public package Foswiki::Func

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public package Foswiki::Func

Interface for Foswiki extensions developers

This module defines the main interfaces that extensions can use to interact with the Foswiki engine and content.

Refer to lib/Foswiki/Plugins/EmptyPlugin.pm for a template Plugin and starter documentation on how to write a Plugin.

Plugins should only call methods in packages documented in DevelopingPlugins. If you use functions in other Foswiki libraries you risk creating a security hole, and you will probably need to change your plugin when you upgrade Foswiki.

Since: date indicates where functions or parameters have been added since the baseline of the API (Foswiki 1.0.0). The date indicates the earliest date of a Foswiki release that will support that function or parameter. See Foswiki:Download.ReleaseDates for version release dates.

Deprecated date indicates where a function or parameters has been deprecated. Deprecated functions will still work, though they should not be called in new plugins and should be replaced in older plugins as soon as possible. Deprecated parameters are simply ignored in Foswiki releases after date.

Until date indicates where a function or parameter has been removed. The date indicates the latest date at which Foswiki releases still supported the function or parameter.

Note that the Foswiki::Func API should always be the first place extension authors look for methods. Certain other lower-level APIs are also exposed by the core, but those APIs should only be called if there is no alternative available through Foswiki::Func. The APIs in question are documented in DevelopingPlugins.

Environment

getSkin( ) -> $skin

Get the skin path, set by the SKIN and COVER preferences variables or the skin and cover CGI parameters

Return: $skin Comma-separated list of skins, e.g. 'gnu,tartan'. Empty string if none.

getUrlHost( ) -> $host

Get protocol, domain and optional port of script URL

Return: $host URL host, e.g. "http://example.com:80"

getScriptUrl( $web, $topic, $script, ... ) -> $url

Compose fully qualified URL

• $web - Web name, e.g. 'Main'
• $topic - Topic name, e.g. 'WebNotify'
• $script - Script name, e.g. 'view'
• ... - an arbitrary number of name=>value parameter pairs that will be url-encoded and added to the url. The special parameter name '#' is reserved for specifying an anchor. e.g. getScriptUrl('x','y','view','#'=>'XXX',a=>1,b=>2) will give .../view/x/y?a=1&b=2#XXX

Return: $url URL, e.g. "http://example.com:80/cgi-bin/view.pl/Main/WebNotify"

Examples:

my $url;
# $url eq 'http://wiki.example.org/url/to/bin'
$url = Foswiki::Func::getScriptUrl();
# $url eq 'http://wiki.example.org/url/to/bin/edit'
$url = Foswiki::Func::getScriptUrl(undef, undef, 'edit');
# $url eq 'http://wiki.example.org/url/to/bin/edit/Web/Topic'
$url = Foswiki::Func::getScriptUrl('Web', 'Topic', 'edit');

getScriptUrlPath( $web, $topic, $script, ... ) -> $path

Compose absolute URL path. See Foswiki::Func::getScriptUrl

Examples:

my $path;
# $path eq '/path/to/bin'
$path = Foswiki::Func::getScriptUrlPath();
# $path eq '/path/to/bin/edit'
$path = Foswiki::Func::getScriptUrlPath(undef, undef, 'edit');
# $path eq '/path/to/bin/edit/Web/Topic'
$path = Foswiki::Func::getScriptUrlPath('Web', 'Topic', 'edit');

Since: 19 Jan 2012 (when called without parameters, this function is backwards-compatible with the old version which was deprecated 28 Nov 2008).

getViewUrl( $web, $topic ) -> $url

Compose fully qualified view URL

• $web - Web name, e.g. 'Main'. The current web is taken if empty
• $topic - Topic name, e.g. 'WebNotify'

Return: $url URL, e.g. "http://example.com:80/cgi-bin/view.pl/Main/WebNotify"

getPubUrlPath( $web, $topic, $attachment, %options ) -> $url

Get pub URL path/attachment URL

Return: with no parameters, returns the URL path of the root of all attachments.

Prior to Foswiki 2, URLs to attachments had to be constructed by the caller. For example, %PUBURL%/Main/JohnSmith/picture.gif This method of constructing URLs causes many problems, and is strongly discouraged.

Since Foswiki 2 this function accepts parameters as follows:

• $web - name of web
• $topic - name of topic (ignored if web is not given)
• $attachment - name of attachment (ignored if web or topic not given)
• %options - additional options

%options may include:

• topic_version - version of topic to retrieve attachment from
• attachment_version - version of attachment to retrieve
• absolute - requests an absolute URL (rather than a relative path)

If $web is not given, $topic and $attachment are ignored. If $topic is not given, $attachment is ignored.

If topic_version is not given, the most recent revision of the topic will be linked. Similarly if attachment_version= is not given, the most recent revision of the attachment will be assumed. If topic_version is specified but attachment_version is not (or the specified attachment_version is not present), then the most recent version of the attachment in that topic version will be linked. Not all stores support retrieving old attachment versions this way.

If absolute is not specified (or is 0), this function will generate relative URLs. However if Foswiki is running in an absolute URL context (the skin requires absolute URLs, such as print or rss, or Foswiki is running from the command-line) then absolute will be ignored and absolute URLs will always be generated.

getExternalResource( $url ) -> $response

Get whatever is at the other end of a URL (using an HTTP GET request). Will only work for encrypted protocols such as https if the LWP CPAN module is installed.

Note that the $url may have an optional user and password, as specified by the relevant RFC. Any proxy set in configure is honoured.

The $response is an object that is known to implement the following subset of the methods of LWP::Response. It may in fact be an LWP::Response object, but it may also not be if LWP is not available, so callers may only assume the following subset of methods is available:

code()

message()

header($field)

content()

is_error()

is_redirect()

Note that if LWP is not available, this function:

1. can only really be trusted for HTTP/1.0 urls. If HTTP/1.1 or another protocol is required, you are strongly recommended to require LWP.
2. Will not parse multipart content

In the event of the server returning an error, then is_error() will return true, code() will return a valid HTTP status code as specified in RFC 2616 and RFC 2518, and message() will return the message that was received from the server. In the event of a client-side error (e.g. an unparseable URL) then is_error() will return true and message() will return an explanatory message. code() will return 400 (BAD REQUEST).

Note: Callers can easily check the availability of other HTTP::Response methods as follows:

my $response = Foswiki::Func::getExternalResource($url);
if (!$response->is_error() && $response->isa('HTTP::Response')) {
    ... other methods of HTTP::Response may be called
} else {
    ... only the methods listed above may be called
}

getRequestObject( ) -> $query

Get the request object. This is a subclass of Foswiki::Request. The request object can be used to get the parameters passed to the request, either via CGI or on the command line (depending on how the script was called).

A Foswiki::Request object is largely compatible with a CPAN:CGI object. Most of the time, documentation for that class applies directly to Foswiki::Request objects as well.

Note that this method replaces getCgiQuery (which is a synonym for this method). Code that is expected to run with pre-1.1 versions of Foswiki can continue to call getCgiQuery for as long as necessary.

Caution: Direct use of the CGI parameters can introduce security vulnerabilities. Any parameters from the URL should be carefully validated, and encoded for safety before displaying the data back to the user.

Example:

   my $query    = Foswiki::Func::getRequestObject();
   my $single   = $query->param('parm1');        # Get a scalar value (Returns 1st value if multiple valued)
   my @multi    = $query->multi_param('parm2');  # Get multi-valued parameter

Since: 31 Mar 2009

getSessionKeys() -> @keys

Get a list of all the names of session variables. The list is unsorted.

Session keys are stored and retrieved using setSessionValue and getSessionValue.

getSessionValue( $key ) -> $value

Get a session value from the client session module

• $key - Session key

Return: $value Value associated with key; empty string if not set

setSessionValue( $key, $value ) -> $boolean

Set a session value.

• $key - Session key
• $value - Value associated with key

Return: true if function succeeded

clearSessionValue( $key ) -> $boolean

Clear a session value that was set using setSessionValue.

• $key - name of value stored in session to be cleared. Note that you cannot clear AUTHUSER.

Return: true if the session value was cleared

getContext() -> \%hash

Get a hash of context identifiers representing the currently active context.

The context is a set of identifiers that are set during specific phases of processing. For example, each of the standard scripts in the 'bin' directory each has a context identifier - the view script has 'view', the edit script has 'edit' etc. So you can easily tell what 'type' of script your Plugin is being called within.

A comprehensive list of core context identifiers used by Foswiki is found in IfStatements#Context_identifiers. Please be careful not to overwrite any of these identifiers!

Context identifiers can be used to communicate between Plugins, and between Plugins and templates. For example, in FirstPlugin.pm, you might write:

sub initPlugin {
   Foswiki::Func::getContext()->{'MyID'} = 1;
   ...

This can be used in SecondPlugin.pm like this:

sub initPlugin {
   if( Foswiki::Func::getContext()->{'MyID'} ) {
      ...
   }
   ...

or in a template, like this:

%TMPL:DEF{"ON"}% Not off %TMPL:END%
%TMPL:DEF{"OFF"}% Not on %TMPL:END%
%TMPL:P{context="MyID" then="ON" else="OFF"}%

or in a topic:

%IF{"context MyID" then="MyID is ON" else="MyID is OFF"}%

Note: all plugins have an automatically generated context identifier if they are installed and initialised. For example, if the FirstPlugin is working, the context ID 'FirstPlugin' will be set.

pushTopicContext($web, $topic)

• $web - new web
• $topic - new topic

Change the Foswiki context, adding the requested $web.$topic onto the preferences stack. Any preferences found in $web.$topic will be used in place of preferences previously set in the stack, provided that they were not finalized in a lower level. Preferences set in the prior web.topic are not cleared. $web.$topic replaces and adds to preferences but does not remove preferences that it does not set.

Note that if the new topic is not readable by the logged in user due to access control considerations, there will not be an exception. It is the duty of the caller to check access permissions before changing the topic. All other errors will throw an exception.

It is the duty of the caller to restore the original context by calling popTopicContext.

Note that this call does not re-initialise plugins, so if you have used global variables to remember the web and topic in initPlugin, then those values will be unchanged.

popTopicContext()

Returns the Foswiki context to the state it was in before the pushTopicContext was called.

Registering extensions

Plugins work either by using handlers to manipulate the text being processed, or by registering extensions, such as new macros, scripts, or meta-data types.

registerTagHandler( $var, \&fn, $syntax )

Should only be called from initPlugin.

Register a function to handle a simple variable. Handles both %VAR% and %VAR{...}%. Registered variables are treated the same as internal macros, and are expanded at the same time. This is a lot more efficient than using the commonTagsHandler.

• $var - The name of the variable, i.e. the 'MYVAR' part of %MYVAR%. The variable name must match /^[A-Z][A-Z0-9_]*$/ or it won't work.
• \&fn - Reference to the handler function.
• $syntax can be 'classic' (the default) or 'context-free'. (context-free may be removed in future) 'classic' syntax is appropriate where you want the variable to support classic syntax

1. e. to accept the standard %MYVAR{ "unnamed" param1="value1" param2="value2" }% syntax, as well as an unquoted default parameter, such as %MYVAR{unquoted parameter}%. If your variable will only use named parameters, you can use 'context-free' syntax, which supports a more relaxed syntax. For example, %MYVAR{param1=value1, value 2, param3="value 3", param4='value 5"}%

The variable handler function must be of the form:

sub handler(\%session, \%params, $topic, $web, $topicObject)

where:

• \%session - a reference to the session object (may be ignored)
• \%params - a reference to a Foswiki::Attrs object containing parameters. This can be used as a simple hash that maps parameter names to values, with _DEFAULT being the name for the default parameter.
• $topic - name of the topic in the query
• $web - name of the web in the query
• $topicObject - is the Foswiki::Meta object for the topic Since 2009-03-06

for example, to execute an arbitrary command on the server, you might do this:

sub initPlugin{
   Foswiki::Func::registerTagHandler('EXEC', \&boo);
}

sub boo {
    my( $session, $params, $topic, $web, $topicObject ) = @_;
    my $cmd = $params->{_DEFAULT};

    return "NO COMMAND SPECIFIED" unless $cmd;

    my $result = `$cmd 2>&1`;
    return $params->{silent} ? '' : $result;
}

would let you do this: %EXEC{"ps -Af" silent="on"}%

Registered tags differ from tags implemented using the old approach (text substitution in commonTagsHandler) in the following ways:

• registered tags are evaluated at the same time as system tags, such as %SERVERTIME. commonTagsHandler is only called later, when all system tags have already been expanded (though they are expanded again after commonTagsHandler returns).
• registered tag names can only contain alphanumerics and _ (underscore)
• registering a tag FRED defines both %FRED{...}% and also %FRED%.
• registered tag handlers cannot return another tag as their only result (e.g. return '%SERVERTIME%';). It won't work.

registerRESTHandler( $alias, \&fn, %options )

Should only be called from initPlugin.

Adds a function to the dispatch table of the REST interface

• $alias - The name .
• \&fn - Reference to the function.
• %options - additional options affecting the handler

The handler function must be of the form:

sub handler(\%session)

where:

• \%session - a reference to the Foswiki session object (may be ignored)

From the REST interface, the name of the plugin must be used as the subject of the invokation.

Additional options are set in the %options hash. These options are important to ensuring that requests to your handler can't be used in cross-scripting attacks, or used for phishing.

• authenticate - use this boolean option to require authentication for the handler. If this is set, then an authenticated session must be in place or the REST call will be rejected with a 401 (Unauthorized) status code. As of Foswiki 2, authenticate defaults to true. If the handler being registered is usable by guests, and does its own checking, pass authenticate => 0 to remove the requirement for an authenticated session.
• validate - use this boolean option to require validation of any requests made to this handler. Validation is the process by which a secret key is passed to the server so it can identify the origin of the request. As of Foswiki 2, validate will default to true. If your handler is typically invoked multipe times on a page, or doesn not need protection from CSRF attacks, set validate => 0.
• http_allow use this option to specify that the HTTP methods that can be used to invoke the handler. For example, http_allow=>'POST,GET' will constrain the handler to be invoked using POST and GET, but not other HTTP methods, such as DELETE. Normally you will use http_allow=>'POST'. Together with authentication this is an important security tool. Handlers that can be invoked using GET are vulnerable to being called in the src parameter of img tags, a common method for cross-site request forgery (CSRF) attacks. As of Foswiki 2, this option will default to http_allow => 'POST'. If your handler does not update, then explicitly set this to http_allow => 'GET,POST'
• description => 'handler information' This is a completely optional short description of the handler function. It is displayed by the %RESTHANDLERS% macro used for extension diagnostics.

See http://foswiki.org/Support/GuidelinesForSecureExtensions for more information.

Example

The EmptyPlugin has the following call in the initPlugin handler:

   Foswiki::Func::registerRESTHandler('example', \&restExample,
     authenticate  => 1,      # Set to 0 if handler should be useable by WikiGuest
     validate      => 1,      # Set to 0 to disable StrikeOne CSRF protection
     http_allow    => 'POST', # Set to 'GET,POST' to allow use HTTP GET and POST
     description   => 'Example handler for Empty Plugin'
     );

This adds the restExample function to the REST dispatch table for the EmptyPlugin under the 'example' alias, and allows it to be invoked using the URL

http://server:port/bin/rest/EmptyPlugin/example

note that the URL

http://server:port/bin/rest/EmptyPlugin/restExample

(ie, with the name of the function instead of the alias) will not work.

Calling REST handlers from the command-line

The rest script allows handlers to be invoked from the command line. The script is invoked passing the parameters as described in CommandAndCGIScripts. If the handler requires authentication ( authenticate=>1 ) then this can be passed in the username and password parameters.

For example,

perl -wT rest /EmptyPlugin/example -username HughPugh -password trumpton

registerMETA($macro, $spec)

Deprecated: please use Foswiki::Meta::registerMETA instead.

Preferences

getPreferencesValue( $key, $web ) -> $value

Get a preferences value for the currently requested context, from the currently request topic, its web and the site.

• $key - Preference name
• $web - Name of web, optional. If defined, we shortcircuit to WebPreferences (ignoring SitePreferences). This is really only useful for ACLs.

Return: $value Preferences value; undefined if not set

• Example for preferences setting:
  • WebPreferences topic has: * Set WEBBGCOLOR = #FFFFC0
  • my $webColor = Foswiki::Func::getPreferencesValue( 'WEBBGCOLOR', 'Sandbox' );

• Example for MyPlugin setting:
  • if the MyPlugin topic has: * Set COLOR = red
  • Use "MYPLUGIN_COLOR" for $key
  • my $color = Foswiki::Func::getPreferencesValue( "MYPLUGIN_COLOR" );

NOTE: If $NO_PREFS_IN_TOPIC is enabled in the plugin, then preferences set in the plugin topic will be ignored.

getPluginPreferencesValue( $key ) -> $value

Get a preferences value from your Plugin

• $key - Plugin Preferences key w/o PLUGINNAME_ prefix.

Return: $value Preferences value; empty string if not set

Note: This function will will only work when called from the Plugin.pm file itself. it will not work if called from a sub-package (e.g. Foswiki::Plugins::MyPlugin::MyModule)

NOTE: If $NO_PREFS_IN_TOPIC is enabled in the plugin, then preferences set in the plugin topic will be ignored.

getPreferencesFlag( $key, $web ) -> $value

Get a preferences flag from Foswiki or from a Plugin

• $key - Preferences key
• $web - Name of web, optional. Current web if not specified; does not apply to settings of Plugin topics

Return: $value Preferences flag '1' (if set), or "0" (for preferences values "off", "no" and "0")

• Example for Plugin setting:
  • MyPlugin topic has: * Set SHOWHELP = off
  • Use "MYPLUGIN_SHOWHELP" for $key
  • my $showHelp = Foswiki::Func::getPreferencesFlag( "MYPLUGIN_SHOWHELP" );

NOTE: If $NO_PREFS_IN_TOPIC is enabled in the plugin, then preferences set in the plugin topic will be ignored.

getPluginPreferencesFlag( $key ) -> $boolean

Get a preferences flag from your Plugin

• $key - Plugin Preferences key w/o PLUGINNAME_ prefix.

Return: false for preferences values "off", "no" and "0", or values not set at all. True otherwise.

Note: This function will will only work when called from the Plugin.pm file itself. it will not work if called from a sub-package (e.g. Foswiki::Plugins::MyPlugin::MyModule)

NOTE: If $NO_PREFS_IN_TOPIC is enabled in the plugin, then preferences set in the plugin topic will be ignored.

setPreferencesValue($name, $val)

Set the preferences value so that future calls to getPreferencesValue will return this value, and %$name% will expand to the preference when used in future variable expansions.

The preference only persists for the rest of this request. Finalised preferences cannot be redefined using this function.

User Handling and Access Control

getDefaultUserName( ) -> $loginName

Get default user name as defined in the configuration as DefaultUserLogin

Return: $loginName Default user name, e.g. 'guest'

getCanonicalUserID( $user ) -> $cUID

• $user can be a login, wikiname or web.wikiname

Return the cUID of the specified user. A cUID is a unique identifier which is assigned by Foswiki for each user. BEWARE: While the default TopicUserMapping uses a cUID that looks like a user's LoginName, some characters may be modified to make them compatible with rcs. Other usermappings may use other conventions - the JoomlaUserMapping for example, has cUIDs like 'JoomlaeUserMapping_1234'.

If $user is undefined, it assumes the currently logged-in user.

Return: $cUID, an internal unique and portable escaped identifier for registered users. This may be autogenerated for an authenticated but unregistered user.

getWikiName( $user ) -> $wikiName

return the WikiName of the specified user if $user is undefined Get Wiki name of logged in user

• $user can be a cUID, login, wikiname or web.wikiname

Return: $wikiName Wiki Name, e.g. 'JohnDoe'

getWikiUserName( $user ) -> $wikiName

return the userWeb.WikiName of the specified user if $user is undefined Get Wiki name of logged in user

• $user can be a cUID, login, wikiname or web.wikiname

Return: $wikiName Wiki Name, e.g. "Main.JohnDoe"

wikiToUserName( $id ) -> $loginName

Translate a Wiki name to a login name.

• $id - Wiki name, e.g. 'Main.JohnDoe' or 'JohnDoe'. $id may also be a login name. This will normally be transparent, but should be borne in mind if you have login names that are also legal wiki names.

Return: $loginName Login name of user, e.g. 'jdoe', or undef if not matched.

Note that it is possible for several login names to map to the same wikiname. This function will only return the first login name that maps to the wikiname.

returns undef if the WikiName is not found.

userToWikiName( $loginName, $dontAddWeb ) -> $wikiName

Translate a login name to a Wiki name

• $loginName - Login name, e.g. 'jdoe'. This may also be a wiki name. This will normally be transparent, but may be relevant if you have login names that are also valid wiki names.
• $dontAddWeb - Do not add web prefix if "1"

Return: $wikiName Wiki name of user, e.g. 'Main.JohnDoe' or 'JohnDoe'

userToWikiName will always return a name. If the user does not exist in the mapping, the $loginName parameter is returned. (backward compatibility)

emailToWikiNames( $email, $dontAddWeb ) -> @wikiNames

• $email - email address to look up
• $dontAddWeb - Do not add web prefix if "1"

Find the wikinames of all users who have the given email address as their registered address. Since several users could register with the same email address, this returns a list of wikinames rather than a single wikiname.

wikinameToEmails( $user ) -> @emails

• $user - wikiname of user to look up

Returns the registered email addresses of the named user. If $user is undef, returns the registered email addresses for the logged-in user.

$user may also be a group.

isGuest( ) -> $boolean

Test if logged in user is a guest (WikiGuest)

isAnAdmin( $id ) -> $boolean

Find out if the user is an admin or not. If the user is not given, the currently logged-in user is assumed.

• $id can be either a login name or a WikiName

isGroupMember( $group, $id, $options ) -> $boolean

Find out if $id is in the named group. The expand option controls whether or not nested groups are searched.

e.g. Is jordi in the HesperionXXGroup, and not in a nested group. e.g.

if( Foswiki::Func::isGroupMember( "HesperionXXGroup", "jordi", { expand => 0 } )) {
    ...
}

If $user is undef, it defaults to the currently logged-in user.

• $id can be a login name or a WikiName
• Nested groups are expanded unless $options{ expand => } is set to false.

eachUser() -> $iterator

Get an iterator over the list of all the registered users not including groups. The iterator will return each wiki name in turn (e.g. 'FredBloggs').

Use it as follows:

    my $it = Foswiki::Func::eachUser();
    while ($it->hasNext()) {
        my $user = $it->next();
        # $user is a wikiname
    }

WARNING on large sites, this could be a long list!

eachMembership($id) -> $iterator

• $id - WikiName or login name of the user. If $id is undef, defaults to the currently logged-in user.

Get an iterator over the names of all groups that the user is a member of.

eachGroup() -> $iterator

Get an iterator over all groups.

Use it as follows:

    my $iterator = Foswiki::Func::eachGroup();
    while ($it->hasNext()) {
        my $group = $it->next();
        # $group is a group name e.g. AdminGroup
    }

WARNING on large sites, this could be a long list!

isGroup( $group ) -> $boolean

Checks if $group is the name of a user group.

eachGroupMember($group) -> $iterator

Get an iterator over all the members of the named group. Returns undef if $group is not a valid group. Nested groups are expanded unless the expand option is set to false.

Use it as follows: Process all users in RadioHeadGroup without expanding nested groups

    my $iterator = Foswiki::Func::eachGroupMember('RadioheadGroup', {expand => 'false');
    while ($it->hasNext()) {
        my $user = $it->next();
        # $user is a wiki name e.g. 'TomYorke', 'PhilSelway'
        #   With expand set to false, group names can also be returned.
        #   Users are not checked to exist.
    }

WARNING on large sites, this could be a long list!

addUserToGroup( $id, $group, $create ) -> $boolean

• $id can be a login name or a WikiName

removeUserFromGroup( $id, $group ) -> $boolean

• $id can be a login name or a WikiName

checkAccessPermission( $type, $id, $text, $topic, $web, $meta ) -> $boolean

Check access permission for a topic based on the System.AccessControl rules

• $type - Access type, required, e.g. 'VIEW', 'CHANGE'.
• $id - WikiName of remote user, required, e.g. "RickShaw". $id may also be a login name. If $id is '', 0 or undef then access is always permitted. This is used by other functions if the caller should be able to bypass access checks.
• $text - Topic text, optional. If 'perl false' (undef, 0 or ''), topic $web.$topic is consulted. $text may optionally contain embedded %META:PREFERENCE tags. Provide this parameter if:
  1. You are setting different access controls in the text to those defined in the stored topic,
  2. You already have the topic text in hand, and want to help avoid having to read it again,
  3. You are providing a $meta parameter.
• $topic - Topic name, optional, e.g. 'PrivateStuff', '' or undef
  • If undefined, the Web preferences are checked.
  • If null, the default (WebHome) topic is checked.
  • If topic specified but does not exist, the web preferences are checked, allowing the caller to determine "If the topic existed, would the operation be permitted".
• $web - Web name, required, e.g. 'Sandbox'
  • If missing, the default Users Web (Main) is used.
• $meta - Meta-data object, as returned by readTopic. Optional. If undef, but $text is defined, then access controls will be parsed from $text. If defined, then metadata embedded in $text will be ignored. This parameter is always ignored if $text is undefined. Settings in $meta override Set settings in $text.

A perl true result indicates that access is permitted.

Note the weird parameter order is due to compatibility constraints with earlier releases.

Tip: if you want, you can use this method to check your own access control types. For example, if you:

• Set ALLOWTOPICSPIN = IncyWincy

in ThatWeb.ThisTopic, then a call to checkAccessPermission('SPIN', 'IncyWincy', undef, 'ThisTopic', 'ThatWeb', undef) will return true.

Example code:

    use Error qw(:try);
    use Foswiki::AccessControlException;
    ...
    unless (
        Foswiki::Func::checkAccessPermission(
            "VIEW", $session->{user}, undef, $topic, $web
        )
      )
    {
        throw Foswiki::AccessControlException( "VIEW", $session->{user}, $web,
            $topic,  $Foswiki::Meta::reason );
    }

Traversing

getListOfWebs( $filter [, $web] ) -> @webs

• $filter - spec of web types to recover

Gets a list of webs, filtered according to the spec in the $filter, which may include one of:

1. 'user' (for only user webs)
2. 'template' (for only template webs i.e. those starting with "_")

$filter may also contain the word 'public' which will further filter out webs that have NOSEARCHALL set on them. 'allowed' filters out webs the current user can't read.

• $web - (Since 2009-01-01) name of web to get list of subwebs for. Defaults to the root. note that if set, the list will not contain the web specified in $web

For example, the deprecated getPublicWebList function can be duplicated as follows:

   my @webs = Foswiki::Func::getListOfWebs( "user,public" );

isValidWebName( $name [, $system] ) -> $boolean

Check for a valid web name. If $system is true, then system web names are considered valid (names starting with _) otherwise only user web names are valid

If $Foswiki::cfg{EnableHierarchicalWebs} is off, it will also return false when a nested web name is passed to it.

webExists( $web ) -> $boolean

Test if web exists

• $web - Web name, required, e.g. 'Sandbox'

getTopicList( $web ) -> @topics

Get list of all topics in a web

• $web - Web name, required, e.g. 'Sandbox'

Return: @topics Topic list, e.g. ( 'WebChanges',  'WebHome', 'WebIndex', 'WebNotify' )

isValidTopicName( $name [, $allowNonWW] ) -> $boolean

Check for a valid topic name.

• $name - topic name
• $allowNonWW - true to allow non-wikiwords

topicExists( $web, $topic ) -> $boolean

Test if topic exists

• $web - Web name, optional, e.g. 'Main'.
• $topic - Topic name, required, e.g. 'TokyoOffice', or "Main.TokyoOffice"

$web and $topic are parsed as described in the documentation for normalizeWebTopicName. Specifically, the User is used if $web is not specified and $topic has no web specifier. To get an expected behaviour it is recommened to specify the current web for $web; don't leave it empty.

readTopic( $web, $topic, $rev ) -> ( $meta, $text )

Read topic text and meta data, regardless of access permissions.

• $web - Web name, required, e.g. 'Main'
• $topic - Topic name, required, e.g. 'TokyoOffice'
• $rev - revision to read (default latest)

Return: ( $meta, $text ) Meta data object and topic text

$meta is a perl 'object' of class Foswiki::Meta. This class is fully documented in the source code documentation shipped with the release, or can be inspected in the lib/Foswiki/Meta.pm file.

This method ignores topic access permissions. You should be careful to use checkAccessPermission to ensure the current user has read access to the topic.

getRevisionInfo($web, $topic, $rev, $attachment ) -> ( $date, $user, $rev, $comment )

Get revision info of a topic or attachment

• $web - Web name, optional, e.g. 'Main'
• $topic - Topic name, required, e.g. 'TokyoOffice'
• $rev - revsion number, or tag name (can be in the format 1.2, or just the minor number)
• $attachment -attachment filename

Return: ( $date, $user, $rev, $comment ) List with: ( last update date, login name of last user, minor part of top revision number, comment of attachment if attachment ), e.g. ( 1234561, 'phoeny', "5",  )

$date	in epochSec
$user	Wiki name of the author (not login name)
$rev	actual rev number
$comment	comment given for uploaded attachment

NOTE: if you are trying to get revision info for a topic, use $meta->getRevisionInfo instead if you can - it is significantly more efficient.

getRevisionAtTime( $web, $topic, $time ) -> $rev

Get the revision number of a topic at a specific time.

• $web - web for topic
• $topic - topic
• $time - time (in epoch secs) for the rev

Return: Single-digit revision number, or undef if it couldn't be determined (either because the topic isn't that old, or there was a problem)

getAttachmentList( $web, $topic ) -> @list

Get a list of the attachments on the given topic.

Since: 31 Mar 2009

attachmentExists( $web, $topic, $attachment ) -> $boolean

Test if attachment exists

• $web - Web name, optional, e.g. Main.
• $topic - Topic name, required, e.g. TokyoOffice, or Main.TokyoOffice
• $attachment - attachment name, e.g.=logo.gif=

$web and $topic are parsed as described in the documentation for normalizeWebTopicName.

The attachment must exist in the store (it is not sufficient for it to be referenced in the object only)

readAttachment( $web, $topic, $name, $rev ) -> $data

• $web - web for topic - must not be tainted
• $topic - topic - must not be tainted
• $name - attachment name - must not be tainted
• $rev - revision to read (default latest)

Read an attachment from the store for a topic, and return it as a string. The names of attachments on a topic can be recovered from the meta-data returned by readTopic. If the attachment does not exist, or cannot be read, undef will be returned. If the revision is not specified, the latest version will be returned.

View permission on the topic is required for the read to be successful. Access control violations are flagged by a Foswiki::AccessControlException. Permissions are checked for the current user.

use Error qw(:try);
use Foswiki::AccessControlException ();

my( $meta, $text ) = Foswiki::Func::readTopic( $web, $topic );
my @attachments = $meta->find( 'FILEATTACHMENT' );
foreach my $a ( @attachments ) {
   try {
       my $data = Foswiki::Func::readAttachment( $web, $topic, $a->{name} );
       ...
   } catch Foswiki::AccessControlException with {
   };
}

This is the way 99% of extensions will access attachments. See Foswiki::Meta::openAttachment for a lower level interface that does not check access controls.

Manipulating

createWeb( $newWeb, $baseWeb, $opts )

• $newWeb is the name of the new web.
• $baseWeb is the name of an existing web (a template web). If the base web is a system web, all topics in it will be copied into the new web. If it is a normal web, only topics starting with 'Web' will be copied. If no base web is specified, an empty web (with no topics) will be created. If it is specified but does not exist, an error will be thrown.
• $opts is a ref to a hash that contains settings to be modified in

the web preferences topic in the new web.

use Error qw( :try );
use Foswiki::AccessControlException ();

try {
    Foswiki::Func::createWeb( "Newweb" );
} catch Foswiki::AccessControlException with {
    my $e = shift;
    # see documentation on Foswiki::AccessControlException
} catch Foswiki::OopsException with {
        shift->throw();    # propagate
} catch Error with {
    my $e = shift;
    # see documentation on Error
} otherwise {
    ...
};

moveWeb( $oldName, $newName )

Move (rename) a web.

use Error qw( :try );
use Foswiki::AccessControlException ();

try {
    Foswiki::Func::moveWeb( "Oldweb", "Newweb" );
} catch Foswiki::AccessControlException with {
    my $e = shift;
    # see documentation on Foswiki::AccessControlException
} catch Foswiki::OopsException with {
        shift->throw();    # propagate
} catch Error with {
    my $e = shift;
    # see documentation on Error::Simple
} otherwise {
    ...
};

To delete a web, move it to a subweb of Trash

Foswiki::Func::moveWeb( "Deadweb", "Trash.Deadweb" );

checkTopicEditLock( $web, $topic, $script ) -> ( $oopsUrl, $loginName, $unlockTime )

Check if a lease has been taken by some other user.

• $web Web name, e.g. "Main", or empty
• $topic Topic name, e.g. "MyTopic", or "Main.MyTopic"

Return: ( $oopsUrl, $loginName, $unlockTime ) - The $oopsUrl for calling redirectCgiQuery(), user's $loginName, and estimated $unlockTime in minutes, or ( '', '', 0 ) if no lease exists.

• $script The script to invoke when continuing with the edit

setTopicEditLock( $web, $topic, $lock )

• $web Web name, e.g. "Main", or empty
• $topic Topic name, e.g. "MyTopic", or "Main.MyTopic"
• $lock 1 to lease the topic, 0 to clear an existing lease

Takes out a "lease" on the topic. The lease doesn't prevent anyone from editing and changing the topic, but it does redirect them to a warning screen, so this provides some protection. The edit script always takes out a lease.

It is impossible to fully lock a topic. Concurrent changes will be merged.

saveTopic( $web, $topic, $meta, $text, $options )

• $web - web for the topic
• $topic - topic name
• $meta - reference to Foswiki::Meta object (optional, set to undef to create a new topic containing just text, or to just change that topic's text)
• $text - text of the topic (without embedded meta-data!!!
• \%options - ref to hash of save options \%options may include:

  dontlog	mark this change so it doesn't appear in the statistics
  minor	True if this change is not to be notified
  forcenewrevision	force the save to increment the revision counter
  ignorepermissions	don't check acls

For example,

use Error qw( :try );
use Foswiki::AccessControlException ();

my( $meta, $text );
if (Foswiki::Func::topicExists($web, $topic)) {
    ( $meta, $text ) = Foswiki::Func::readTopic( $web, $topic );
} else {
    #if the topic doesn't exist, we can either leave $meta undefined
    #or if we need to set more than just the topic text, we create a new Meta object and use it.
    $meta = new Foswiki::Meta($Foswiki::Plugins::SESSION, $web, $topic );
    $text = '';
}
$text =~ s/APPLE/ORANGE/g;
try {
    Foswiki::Func::saveTopic( $web, $topic, $meta, $text );
} catch Foswiki::AccessControlException with {
    my $e = shift;
    # see documentation on Foswiki::AccessControlException
} catch Foswiki::OopsException with {
        shift->throw();    # propagate
} catch Error with {
    my $e = shift;
    # see documentation on Error::Simple
} otherwise {
    ...
};

In the event of an error an exception will be thrown. Callers can elect to trap the exceptions thrown, or allow them to propagate to the calling environment. May throw Foswiki::OopsException or Error::Simple.

Note: The ignorepermissions option is only available in Foswiki 1.1 and later.

moveTopic( $web, $topic, $newWeb, $newTopic )

• $web source web - required
• $topic source topic - required
• $newWeb dest web
• $newTopic dest topic

Renames the topic. Throws an exception if something went wrong. If $newWeb is undef, it defaults to $web. If $newTopic is undef, it defaults to $topic.

The destination topic must not already exist.

Rename a topic to the $Foswiki::cfg{TrashWebName} to delete it.

use Error qw( :try );

try {
    moveTopic( "Work", "TokyoOffice", "Trash", "ClosedOffice" );
} catch Foswiki::AccessControlException with {
    my $e = shift;
    # see documentation on Foswiki::AccessControlException
} catch Foswiki::OopsException with {
        shift->throw();    # propagate
} catch Error with {
    my $e = shift;
    # see documentation on Error::Simple
} otherwise {
    ...
};

saveAttachment( $web, $topic, $attachment, \%opts )

• $web - web for topic
• $topic - topic to atach to
• $attachment - name of the attachment
• \%opts - Ref to hash of options

Create an attachment on the given topic. \%opts may include:

dontlog	mark this change so it is not picked up in statistics
comment	comment for save
hide	if the attachment is to be hidden in normal topic view
stream	Stream of file to upload
file	Name of a file to use for the attachment data. ignored if stream is set. Local file on the server.
filepath	Client path to file
filesize	Size of uploaded data
filedate	Date
createlink	Set true to create a link at the end of the topic
notopicchange	Set to true to prevent this upload being recorded in the meta-data of the topic.

Save an attachment to the store for a topic. On success, returns undef. If there is an error, an exception will be thrown. The current user must have CHANGE access on the topic being attached to.

    try {
        Foswiki::Func::saveAttachment( $web, $topic, 'image.gif',
                                     { file => 'image.gif',
                                       comment => 'Picture of Health',
                                       hide => 1 } );
   } catch Foswiki::AccessControlException with {
      # Topic CHANGE access denied
   } catch Foswiki::OopsException with {
        shift->throw();    # propagate
   } catch Error with {
      # see documentation on Error
   } otherwise {
      ...
   };

This is the way 99% of extensions will create new attachments. See Foswiki::Meta::openAttachment for a much lower-level interface.

moveAttachment( $web, $topic, $attachment, $newWeb, $newTopic, $newAttachment )

• $web source web - required
• $topic source topic - required
• $attachment source attachment - required
• $newWeb dest web
• $newTopic dest topic
• $newAttachment dest attachment

Renames the attachment. Throws an exception on error or access violation. If $newWeb is undef, it defaults to $web. If $newTopic is undef, it defaults to $topic. If $newAttachment is undef, it defaults to $attachment. If all of $newWeb, $newTopic and $newAttachment are undef, it is an error.

The destination topic must already exist, but the destination attachment must not exist.

Rename an attachment to $Foswiki::cfg{TrashWebName}.TrashAttament to delete it.

use Error qw( :try );

try {
   # move attachment between topics
   moveAttachment( "Countries", "Germany", "AlsaceLorraine.dat",
                     "Countries", "France" );
   # Note destination attachment name is defaulted to the same as source
} catch Foswiki::AccessControlException with {
   my $e = shift;
   # see documentation on Foswiki::AccessControlException
} catch Foswiki::OopsException with {
        shift->throw();    # propagate
} catch Error with {
   my $e = shift;
   # see documentation on Error
};

copyAttachment( $web, $topic, $attachment, $newWeb, $newTopic, $newAttachment )

• $web source web - required
• $topic source topic - required
• $attachment source attachment - required
• $newWeb dest web
• $newTopic dest topic
• $newAttachment dest attachment

Copies the attachment. Throws an exception on error or access violation. If $newWeb is undef, it defaults to $web. If $newTopic is undef, it defaults to $topic. If $newAttachment is undef, it defaults to $attachment. If all of $newWeb, $newTopic and $newAttachment are undef, it is an error.

The destination topic must already exist, but the destination attachment must not exist.

use Error qw( :try );

try {
   # copy attachment between topics
   copyAttachment( "Countries", "Germany", "AlsaceLorraine.dat",
                     "Countries", "France" );
   # Note destination attachment name is defaulted to the same as source
} catch Foswiki::AccessControlException with {
   my $e = shift;
   # see documentation on Foswiki::AccessControlException
} catch Foswiki::OopsException with {
        shift->throw();    # propagate
} catch Error with {
   my $e = shift;
   # see documentation on Error
};

Since: 19 Jul 2010

Finding changes

eachChangeSince($web, $time) -> $iterator

Get an iterator over the list of all the changes in the given web between $time and now. $time is a time in seconds since 1st Jan 1970, and is not guaranteed to return any changes that occurred before (now - {Store}{RememberChangesFor}). {Store}{RememberChangesFor}) is a setting in configure. Changes are returned in most-recent-first order.

Use it as follows:

    my $iterator = Foswiki::Func::eachChangeSince(
        $web, time() - 7 * 24 * 60 * 60); # the last 7 days
    while ($iterator->hasNext()) {
        my $change = $iterator->next();
        ...
    }

$change is a reference to a hash containing the following fields:

• verb - the action - one of
  • update - a web, topic or attachment has been modified
  • insert - a web, topic or attachment is being inserted
  • remove - a topic or attachment is being removed
• time - time of the change, in epoch-secs
• cuid - canonical UID of the user who is making the change
• revision - the revision of the topic that the change appears in
• path - web.topic path for the affected
• attachment - attachment name (optional)
• oldpath - web.topic path for the origin of a move
• oldattachment - origin of move
• minor - boolean true if this change is flagged as minor
• comment - descriptive text

The following additional fields are deprecated and will be removed in Foswiki 2.0:

• more - formatted string indicating if the change was minor or not
• topic - name of the topic the change occurred to
• user - wikiname of the user who made the change

These additional fields

If you are writing an extension that requires compatibility with Foswiki < 2 only the more, revision, time, topic and user can be assumed.

summariseChanges($web, $topic, $orev, $nrev, $tml, $nochecks) -> $text

Generate a summary of the changes between rev $orev and rev $nrev of the given topic.

• $web, $topic - topic (required)
• $orev - older rev (required)
• $nrev - later rev (may be undef for the latest)
• $tml - if true will generate renderable TML (i.e. HTML with NOPs. if false will generate a summary suitable for use in plain text (mail, for example)

Generate a (max 3 line) summary of the differences between the revs.

• $nochecks if true, will suppress access control checks. (Since 2.0)

If there is only one rev, a topic summary will be returned.

If $tml is not set, all HTML will be removed.

In non-tml, lines are truncated to 70 characters. Differences are shown using + and - to indicate added and removed text.

If access is denied to either revision, then it will be treated as blank text.

Since 2009-03-06

Templates

readTemplate( $name, $skin ) -> $text

Read a template or skin. Embedded template directives get expanded

• $name - Template name, e.g. 'view'
• $skin - Comma-separated list of skin names, optional, e.g. 'print'

Return: $text Template text

loadTemplate ( $name, $skin, $web ) -> $text

• $name - template file name
• $skin - comma-separated list of skins to use (default: current skin)
• $web - the web to look in for topics that contain templates (default: current web)

Return: expanded template text (what's left after removal of all %TMPL:DEF% statements)

Reads a template and extracts template definitions, adding them to the list of loaded templates, overwriting any previous definition.

How Foswiki searches for templates is described in SkinTemplates.

If template text is found, extracts include statements and fully expands them.

expandTemplate( $def ) -> $string

Do a %TMPL:P{$def}%, only expanding the template (not expanding any variables other than %TMPL%.)

• $def - template name or parameters (as a string)

Return: the text of the expanded template

A template is defined using a %TMPL:DEF% statement in a template file. See the documentation on Foswiki templates for more information.

eg: #load the templates (relying on the system-wide skin path.) Foswiki::Func::loadTemplate('linkedin'); #get the 'profile' DEF section my $tml = Foswiki::Func::expandTemplate('profile'); #get the 'profile' DEF section expanding the inline Template macros (such as %USER% and %TYPE%) #NOTE: when using it this way, it is important to use the double quotes "" to delineate the values of the parameters. my $tml = Foswiki::Func::expandTemplate( '"profile" USER="' . $user . '" TYPE="' . $type . '"' );

Rendering

expandCommonVariables( $text, $topic, $web, $meta ) -> $text

Expand all common %VARIABLES%

• $text - Text with variables to expand, e.g. 'Current user is %WIKIUSER%'
• $topic - Current topic name, optional, e.g. 'WebNotify'
• $web - Web name, optional, e.g. 'Main'. The current web is taken if missing
• $meta - topic meta-data to use while expanding

Return: $text Expanded text, e.g. 'Current user is WikiGuest'

See also: expandVariablesOnTopicCreation

Caution: This function needs all the installed plugins to have gone through initialization. Never call this function from within an initPlugin handler, bad things happen.

Caution: This function ultimately calls the following handlers:

• beforeCommonTagsHandler
• commonTagsHandler
• registered macro handlers
• afterCommonTagsHandler

It is possible to create an infinite loop if expandCommonVariables is called in any of these handlers. It can be used, but care should be taken to ensure that the text being expanded does not cause this function to be called recursively.

expandVariablesOnTopicCreation ( $text ) -> $text

Expand the limited set of variables that are always expanded during topic creation

• $text - the text to process

Return: text with variables expanded

Expands only the variables expected in templates that must be statically expanded in new content.

The expanded variables are:

• %DATE% Signature-format date
• %SERVERTIME% See Macros
• %GMTIME% See Macros
• %USERNAME% Base login name
• %WIKINAME% Wiki name
• %WIKIUSERNAME% Wiki name with prepended web
• %URLPARAM{...}% - Parameters to the current CGI query
• %NOP% No-op

See also: expandVariables

renderText( $text, $web, $topic ) -> $text

Render text from TML into XHTML as defined in System.TextFormattingRules

• $text - Text to render, e.g. '*bold* text and =fixed font='
• $web - Web name, optional, e.g. 'Main'. The current web is taken if missing
• $topic - topic name, optional, defaults to web home

Return: $text XHTML text, e.g. '<b>bold</b> and <code>fixed font</code>'

NOTE: renderText expects that all %MACROS% have already been expanded - it does not expand them for you (call expandCommonVariables above).

internalLink( $pre, $web, $topic, $label, $anchor, $createLink ) -> $text

Render topic name and link label into an XHTML link. Normally you do not need to call this funtion, it is called internally by renderText()

• $pre - Text occuring before the link syntax, optional
• $web - Web name, required, e.g. 'Main'
• $topic - Topic name to link to, required, e.g. 'WebNotify'
• $label - Link label, required. Usually the same as $topic, e.g. 'notify'
• $anchor - Anchor, optional, e.g. '#Jump'
• $createLink - Set to '1' to add question linked mark after topic name if topic does not exist;
  set to '0' to suppress link for non-existing topics

Return: $text XHTML anchor, e.g. '<a href='/cgi-bin/view/Main/WebNotify#Jump'>notify</a>'

addToZone( $zone, $id, $data, $requires )

Direct interface to %ADDTOZONE (see VarADDTOZONE)

• $zone - name of the zone
• $id - unique ID
• $data - the content.
• requires optional, comma-separated list of $id identifiers that should precede the content

All macros present in $data will be expanded before being inserted into the <head> section.

Note: Read the developer supplement at Foswiki:Development.AddToZoneFromPluginHandlers if you are calling addToZone() from a rendering or macro/tag-related plugin handler

Examples:

Foswiki::Func::addToZone( 'head', 'PATTERN_STYLE',
   '<link rel="stylesheet" type="text/css" href="%PUBURL%/Foswiki/PatternSkin/layout.css" media="all" />');

Foswiki::Func::addToZone( 'script', 'MY_JQUERY',
   '<script type="text/javascript" src="%PUBURL%/Myweb/MyJQuery/myjquery.js"></scipt>',
   'JQUERYPLUGIN::FOSWIKI');

Controlling page output

writeHeader()

Prints a basic content-type HTML header for text/html to standard out.

redirectCgiQuery( $query, $url, $passthru, $status )

Redirect to URL

• $query - CGI query object. Ignored, only there for compatibility. The session CGI query object is used instead.
• $url - URL to redirect to
• $passthru - enable passthrough.
• $status - HTTP status code (30x) to redirect with. Optional, defaults to 302. Since 2012-03-28

Return: none

Issue a Location HTTP header that will cause a redirect to a new URL. Nothing more should be printed to STDOUT after this method has been called.

The $passthru parameter allows you to pass the parameters that were passed to the current query on to the target URL, as long as it is another URL on the same installation. If $passthru is set to a true value, then Foswiki will save the current URL parameters, and then try to restore them on the other side of the redirect. Parameters are stored on the server in a cache file.

Note that if $passthru is set, then any parameters in $url will be lost when the old parameters are restored. if you want to change any parameter values, you will need to do that in the current CGI query before redirecting e.g.

my $query = Foswiki::Func::getRequestObject();
$query->param(-name => 'text', -value => 'Different text');
Foswiki::Func::redirectCgiQuery(
  undef, Foswiki::Func::getScriptUrl($web, $topic, 'edit'), 1);

$passthru does nothing if $url does not point to a script in the current Foswiki installation.

Plugin-specific file handling

getWorkArea( $pluginName ) -> $directorypath

Gets a private directory for Plugin use. The Plugin is entirely responsible for managing this directory; Foswiki will not read from it, or write to it.

The directory is guaranteed to exist, and to be writable by the webserver user. By default it will not be web accessible.

The directory and its contents are permanent, so Plugins must be careful to keep their areas tidy.

For temporary file storage that only exists for the life of the transaction, use the Perl File::Temp or related File::Spec functions.

readFile( $filename, $unicode ) -> $text

Read file, low level. Used for Plugin workarea.

• $filename - Full path name of file
• $unicode - Specify that file contains unicode text New with Foswiki 2.0

Return: $text Content of file, empty if not found

NOTE: Use this function only for the Plugin workarea, not for topics and attachments. Use the appropriate functions to manipulate topics and attachments.

Foswiki 2.0 APIs generally all use UNICODE strings, and all data is properly decoded from/to utf-8 at the edge. This API is an exception! Because this API can be used to retrieve data of any type including binary data, it is not decoded to unicode by default. By default, data is read as raw bytes, without any encoding layer.

If you are using this API to read topic originated data, topic names, etc. then you should set the $unicode flag so that the data returned is a valid perl character string.

saveFile( $filename, $text, $unicode )

Save file, low level. Used for Plugin workarea.

• $filename - Full path name of file
• $text - Text to save
• $unicode - Flag indicates that $text string should be saved as utf-8. New with Foswiki 2.0

Return: none

NOTE: Use this function only for the Plugin workarea, not for topics and attachments. Use the appropriate functions to manipulate topics and attachments.

Foswiki 2.0 APIs generally all use UNICODE strings, and all data is properly decoded from/to utf-8 at the edge. This API is an exception! Because this API can be used to save data of any type including binary data, it is not decoded to unicode by default. By default, data is written as raw bytes, without any encoding layer.

If you are using this API to write topic data, topic names, etc. then you should set the $unicode flag so that the data returned as a valid perl character string.

Failure to set the $unicode flag when required will result in perl "Wide character in print" errors.

General Utilities

normalizeWebTopicName($web, $topic) -> ($web, $topic)

Parse a web and topic name, supplying defaults as appropriate.

• $web - Web name, identifying variable, or empty string
• $topic - Topic name, may be a web.topic string, required.

Return: the parsed Web/Topic pair

Input	Return
( 'Web', 'Topic' )	( 'Web', 'Topic' )
( '', 'Topic' )	( 'Main', 'Topic' )
( '', '' )	( 'Main', 'WebHome' )
( '', 'Web/Topic' )	( 'Web', 'Topic' )
( '', 'Web/Subweb/Topic' )	( 'Web/Subweb', 'Topic' )
( '', 'Web.Topic' )	( 'Web', 'Topic' )
( '', 'Web.Subweb.Topic' )	( 'Web/Subweb', 'Topic' )
( 'Web1', 'Web2.Topic' )	( 'Web2', 'Topic' )
( 'Web1', 'Web2.' )	( 'Web2', 'WebHome' )

Note that sub web names (SubWeb) are only available if hierarchical webs are enabled in configure.

The symbols %USERSWEB%, %SYSTEMWEB% and %DOCWEB% can be used in the input to represent the web names set in $cfg{UsersWebName} and $cfg{SystemWebName}. For example:

Input	Return
( '%USERSWEB%', 'Topic' )	( 'Main', 'Topic' )
( '%SYSTEMWEB%', 'Topic' )	( 'System', 'Topic' )
( '', '%DOCWEB%.Topic' )	( 'System', 'Topic' )

query($searchString, $topics, \%options ) -> iterator (resultset)

Query the topic data in the specified webs. A programatic interface to SEARCH results.

• $searchString - the search string, as appropriate for the selected type
• $topics - undef OR reference to a ResultSet, Iterator, or array containing the web.topics to be evaluated. if undef, then all the topics in the webs specified will be evaluated.
• \%option - reference to an options hash

The \%options hash may contain the following options:

• type - regex, keyword, query, ... defaults to query
• web - The web/s to search in - string can have the same form as the web param of SEARCH (if not specified, defaults to BASEWEB)
• casesensitive - false to ignore case (default true)
• files_without_match - true to return files only (default false). If files_without_match is specified, it will return on the first match in each topic (i.e. it will return only one match per
• topic, excludetopic and other params as per SEARCH)
• includeTopics - Seach only in this topic, a topic with asterisk wildcards, or a list of topics separated by comma
• excludeTopics - Exclude search in this topic, a topic with asterisk wildcards, or a list of topics separated by comma

To iterate over the returned topics use:

    my $matches = Foswiki::Func::query( "Slimy Toad", undef,
            { web => 'Main,San*', casesensitive => 0, files_without_match => 0 } );
    while ($matches->hasNext) {
        my $webtopic = $matches->next;
        my ($web, $topic) = Foswiki::Func::normalizeWebTopicName('', $webtopic);
      ...etc

decodeFormatTokens($str) -> $unencodedString

Foswiki has an informal standard set of tokens used in format parameters that are used to block evaluation of paramater strings. For example, if you were to write

%MYTAG{format="%WURBLE%"}%

then %WURBLE would be expanded before %MYTAG is evaluated. To avoid this Foswiki uses escapes in the format string. For example:

%MYTAG{format="$percentWURBLE$percent"}%

This lets you enter arbitrary strings into parameters without worrying that Foswiki will expand them before your plugin gets a chance to deal with them properly. Once you have processed your tag, you will want to expand these tokens to their proper value. That's what this function does.

The set of tokens that is expanded is described in FormatTokens.

sanitizeAttachmentName($fname) -> ($fileName, $origName)

Given a file path, sanitise it according to the rules for transforming attachment names. Returns the sanitised name together with the basename before sanitisation.

Sanitation includes filtering illegal characters and mapping client file names to legal server names.

Avoid using this if you can; rewriting attachment names uses some very nasty heuristics that cannot be changed because of compatibility issues. It is much better use point-of-source validation to ensure only valid attachment names are uploaded.

spaceOutWikiWord( $word, $sep ) -> $text

Spaces out a wiki word by inserting a string (default: one space) between each word component. With parameter $sep any string may be used as separator between the word components; if $sep is undefined it defaults to a space.

isTrue( $value, $default ) -> $boolean

Returns 1 if $value is true, and 0 otherwise. "true" means set to something with a Perl true value, with the special cases that "off", "false" and "no" (case insensitive) are forced to false. Leading and trailing spaces in $value are ignored.

If the value is undef, then $default is returned. If $default is not specified it is taken as 0.

isValidWikiWord ( $text ) -> $boolean

Check for a valid WikiWord or WikiName

• $text - Word to test

extractParameters($attr ) -> %params

Extract all parameters from a variable string and returns a hash of parameters

• $attr - Attribute string

Return: %params Hash containing all parameters. The nameless parameter is stored in key _DEFAULT

• Example:
  • Variable: %TEST{ 'nameless' name1="val1" name2="val2" }%
  • First extract text between {...} to get: 'nameless' name1="val1" name2="val2"
  • Then call this on the text:
    
• params = Foswiki::Func::extractParameters( $text );=
  • The %params hash contains now:
    _DEFAULT => 'nameless'
name1 => "val1"
name2 => "val2"

extractNameValuePair( $attr, $name ) -> $value

Extract a named or unnamed value from a variable parameter string - Note: | Function Foswiki::Func::extractParameters is more efficient for extracting several parameters

• $attr - Attribute string
• $name - Name, optional

Return: $value Extracted value

• Example:
  • Variable: %TEST{ 'nameless' name1="val1" name2="val2" }%
  • First extract text between {...} to get: 'nameless' name1="val1" name2="val2"
  • Then call this on the text:
    my $noname = Foswiki::Func::extractNameValuePair( $text );
my $val1  = Foswiki::Func::extractNameValuePair( $text, "name1" );
my $val2  = Foswiki::Func::extractNameValuePair( $text, "name2" );

sendEmail ( $text, $retries ) -> $error

• $text - text of the mail, including MIME headers
• $retries - number of times to retry the send (default 1)

Send an e-mail specified as MIME format content. To specify MIME format mails, you create a string that contains a set of header lines that contain field definitions and a message body such as:

To: liz@windsor.gov.uk
From: serf@hovel.net
CC: george@whitehouse.gov
Subject: Revolution

Dear Liz,

Please abolish the monarchy (with King George's permission, of course)

Thanks,

A. Peasant

Leave a blank line between the last header field and the message body.

Logging

writeEvent( $action, $extra )

Log an event.

• $action - name of the event (keep them unique!)
• $extra - arbitrary extra information to add to the log.

You can enumerate the contents of the log using the eachEventSince function.

NOTE: Older plugins may use $Foswiki::cfg{LogFileName}. These plugins must be modified to use writeEvent and eachEventSince instead.

To maintain compatibility with older Foswiki releases, you can write conditional code as follows:

if (defined &Foswiki::Func::writeEvent) {
   # use writeEvent and eachEventSince
} else {
   # old code using {LogFileName}
}

Note that the ability to read/write $Foswiki::cfg{LogFileName} is maintained for compatibility but is deprecated (should not be used in new code intended to work only with Foswiki 1.1 and later) and will not work with any installation that stores logs in a database.

writeWarning( $text )

Log a warning that may require admin intervention to the warnings log (data/warn*.txt)

• $text - Text to write; timestamp gets added

writeDebug( $text )

Log debug message to the debug log

• $text - Text to write; timestamp gets added

eachEventSince($time, $level) -> $iterator

• $time - a time in the past (seconds since the epoch)
• $level - log level to return events for.

Get an iterator over the list of all the events at the given level between $time and now. Events are written to the event log using writeEvent. The Foswiki core will write other events that will also be returned.

If the chosen Logger does not support querying the logs, an empty iterator will be returned. The supplied PlainFile and Compatibility loggers will return events only if the log files have not been archived.

Events are returned in oldest-first order.

Each event is returned as a reference to an array. The elements are:

1. date of the event (seconds since the epoch)
2. login name of the user who triggered the event
3. the event name (the $action passed to writeEvent)
4. the Web.Topic that the event applied to
5. Extras (the $extra passed to writeEvent)
6. The IP address that was the source of the event (if known)

Use the iterator like this:

my $it = Foswiki::Func::eachEventSince(Foswiki::Time::parseTime("1 Apr 2010"));
while ($it->hasNext()) {
   my $entry = $it->next();
   my $date = $entry->[0];
   my $loginName = $entry->[1];
   ...
}

Deprecated functions

From time-to-time, the Foswiki developers will add new functions to the interface (either to Foswiki::Func, or new handlers). Sometimes these improvements mean that old functions have to be deprecated to keep the code manageable. When this happens, the deprecated functions will be supported in the interface for at least one more release, and probably longer, though this cannot be guaranteed.

Updated plugins may still need to define deprecated handlers for compatibility with old Foswiki versions. In this case, the plugin package that defines old handlers can suppress the warnings in %FAILEDPLUGINS%.

This is done by defining a map from the handler name to the Foswiki::Plugins version in which the handler was first deprecated. For example, if we need to define the endRenderingHandler for compatibility with Foswiki::Plugins versions before 1.1, we would add this to the plugin:

package Foswiki::Plugins::SinkPlugin;
use vars qw( %FoswikiCompatibility );
$FoswikiCompatibility{endRenderingHandler} = 1.1;

If the currently-running code version is 1.1 or later, then the handler will not be called and the warning will not be issued. Wersions of Foswiki::Plugins before 1.1 will still call the handler as required.

The following functions are retained for compatibility only. You should stop using them as soon as possible.

getRegularExpression( $name ) -> $expr

Deprecated 28 Nov 2008 - use $Foswiki::regex{...} instead, it is directly equivalent.

See DevelopingPlugins for more information

getWikiToolName( ) -> $name

Deprecated 28 Nov 2008 in Foswiki; use $Foswiki::cfg{WikiToolName} instead

getMainWebname( ) -> $name

Deprecated 28 Nov 2008 in Foswiki; use $Foswiki::cfg{UsersWebName} instead

getTwikiWebname( ) -> $name

Deprecated 28 Nov 2008 in Foswiki; use $Foswiki::cfg{SystemWebName} instead

getOopsUrl( $web, $topic, $template, $param1, $param2, $param3, $param4 ) -> $url

Compose fully qualified 'oops' dialog URL

• $web - Web name, e.g. 'Main'. The current web is taken if empty
• $topic - Topic name, e.g. 'WebNotify'
• $template - Oops template name, e.g. 'oopsmistake'. The 'oops' is optional; 'mistake' will translate to 'oopsmistake'.
• $param1 ... $param4 - Parameter values for %PARAM1% ... %PARAMn% variables in template, optional

Return: $url URL, e.g. "http://example.com:80/cgi-bin/oops.pl/ Main/WebNotify?template=oopslocked&param1=joe"

Deprecated 28 Nov 2008, the recommended approach is to throw an oops exception.

   use Error qw( :try );

   throw Foswiki::OopsException(
      'toestuckerror',
      web => $web,
      topic => $topic,
      params => [ 'I got my toe stuck' ]);

(this example will use the oopstoestuckerror template.)

If this is not possible (e.g. in a REST handler that does not trap the exception) then you can use getScriptUrl instead:

   my $url = Foswiki::Func::getScriptUrl($web, $topic, 'oops',
            template => 'oopstoestuckerror',
            param1 => 'I got my toe stuck');
   Foswiki::Func::redirectCgiQuery( undef, $url );
   return 0;

wikiToEmail( $wikiName ) -> $email

• $wikiname - wiki name of the user

Get the e-mail address(es) of the named user. If the user has multiple e-mail addresses (for example, the user is a group), then the list will be comma-separated.

Deprecated 28 Nov 2008 in favour of wikinameToEmails, because this function only returns a single email address, where a user may in fact have several.

$wikiName may also be a login name.

permissionsSet( $web ) -> $boolean

Test if any access restrictions are set for this web, ignoring settings on individual pages

• $web - Web name, required, e.g. 'Sandbox'

Deprecated 28 Nov 2008 - use getPreferencesValue instead to determine what permissions are set on the web, for example:

foreach my $type (qw( ALLOW DENY )) {
    foreach my $action (qw( CHANGE VIEW )) {
        my $pref = $type . 'WEB' . $action;
        my $val = Foswiki::Func::getPreferencesValue( $pref, $web ) || '';
        if( $val =~ m/\S/ ) {
            print "$pref is set to $val on $web\n";
        }
    }
}

getPublicWebList( ) -> @webs

Deprecated 28 Nov 2008 - use getListOfWebs instead.

Get list of all public webs, e.g. all webs and subwebs that do not have the NOSEARCHALL flag set in the WebPreferences

Return: @webs List of all public webs and subwebs

formatTime( $time, $format, $timezone ) -> $text

Deprecated 28 Nov 2008 - use Foswiki::Time::formatTime instead (it has an identical interface).

Format the time in seconds into the desired time string

• $time - Time in epoch seconds
• $format - Format type, optional. Default e.g. '31 Dec 2002 - 19:30'. Can be '$iso' (e.g. '2002-12-31T19:30Z'), '$rcs' (e.g. '2001/12/31 23:59:59', '$http' for HTTP header format (e.g. 'Thu, 23 Jul 1998 07:21:56 GMT'), or any string with tokens '$seconds, $minutes, $hours, $day, $wday, $month, $mo, $year, $ye, $tz' for seconds, minutes, hours, day of month, day of week, 3 letter month, 2 digit month, 4 digit year, 2 digit year, timezone string, respectively
• $timezone - either not defined (uses the displaytime setting), 'gmtime', or 'servertime'

Return: $text Formatted time string

Note:

if you used the removed formatGmTime, add a third parameter 'gmtime'

formatGmTime( $time, $format ) -> $text

Deprecated 28 Nov 2008 - use Foswiki::Time::formatTime instead.

Format the time to GM time

• $time - Time in epoc seconds
• $format - Format type, optional. Default e.g. '31 Dec 2002 - 19:30', can be 'iso' (e.g. '2002-12-31T19:30Z'), 'rcs' (e.g. '2001/12/31 23:59:59', 'http' for HTTP header format (e.g. 'Thu, 23 Jul 1998 07:21:56 GMT')

Return: $text Formatted time string

getDataDir( ) -> $dir

Deprecated 28 Nov 2008 - use the "Webs, Topics and Attachments" functions to manipulate topics instead

getPubDir( ) -> $dir

Deprecated 28 Nov 2008 - use the "Webs, Topics and Attachments" functions to manipulate attachments instead

getCgiQuery( ) -> $query

Deprecated 31 Mar 2009 - use getRequestObject instead if you can. Code that is expected to run with pre-1.1 versions of Foswiki will still need to use this method, as getRequestObject will not be available.

readTopicText( $web, $topic, $rev, $ignorePermissions ) -> $text

Read topic text, including meta data

• $web - Web name, e.g. 'Main', or empty
• $topic - Topic name, e.g. 'MyTopic', or "Main.MyTopic"
• $rev - Topic revision to read, optional. Specify the minor part of the revision, e.g. "5", not "1.5"; the top revision is returned if omitted or empty.
• $ignorePermissions - Set to "1" if checkAccessPermission() is already performed and OK; an oops URL is returned if user has no permission

Return: $text Topic text with embedded meta data; an oops URL for calling redirectCgiQuery() is returned in case of an error

*Deprecated: 6 Aug 2009. Use readTopic instead. This method returns meta-data embedded in the text. Plugins authors must be very careful to avoid damaging meta-data. Use readTopic instead, which is a lot safer and supports the full set of read options.

saveTopicText( $web, $topic, $text, $ignorePermissions, $dontNotify ) -> $oopsUrl

Save topic text, typically obtained by readTopicText(). Topic data usually includes meta data; the file attachment meta data is replaced by the meta data from the topic file if it exists.

• $web - Web name, e.g. 'Main', or empty
• $topic - Topic name, e.g. 'MyTopic', or "Main.MyTopic"
• $text - Topic text to save, assumed to include meta data
• $ignorePermissions - Set to "1" if checkAccessPermission() is already performed and OK
• $dontNotify - Set to "1" if not to notify users of the change

Deprecated 6 Aug 2009 - use saveTopic instead. saveTopic supports embedded meta-data in the saved text, and also supports the full set of save options.

Return: $oopsUrl Empty string if OK; the $oopsUrl for calling redirectCgiQuery() in case of error

my $text = Foswiki::Func::readTopicText( $web, $topic );

# check for oops URL in case of error:
if( $text =~ m/^http.*?\/oops/ ) {
    Foswiki::Func::redirectCgiQuery( $query, $text );
    return;
}
# do topic text manipulation like:
$text =~ s/old/new/g;
# do meta data manipulation like:
$text =~ s/(META\:FIELD.*?name\=\"TopicClassification\".*?value\=\")[^\"]*/$1BugResolved/;
$oopsUrl = Foswiki::Func::saveTopicText( $web, $topic, $text ); # save topic text

addToHEAD( $id, $data, $requires )

Adds $data to the HTML header (the <head> tag).

Deprecated 26 Mar 2010 - use addZoZone('head', ...).

Note: Any calls using addToHEAD for javascript should be rewritten to use the new script zone in addToZone as soon as possible.

Rewrite:

Foswiki::Func::addToHEAD("id", "<script>...</script>", "JQUERYPLUGIN");

To:

Foswiki::Func::addToZone("script", "id", "<script>...</script>", "JQUERYPLUGIN");

The reason is that all <script> markup should be added to a dedicated zone, script, and so any usage of ADDTOHEAD - which adds to the head zone - will be unable to satisfy ordering requirements when the requirements exist in another zone ( script ).

See Foswiki:Development/UpdatingExtensionsScriptZone for more details.

searchInWebContent($searchString, $web, \@topics, \%options ) -> reference to a hash - keys of which are topic names

Deprecated 17 Oct 2010 - use query( ...). WARNING: This function has been deprecated in foswiki 1.1.0 for scalability reasons

Search for a string in the content of a web. The search is over all content, including meta-data. Meta-data matches will be returned as formatted lines within the topic content (meta-data matches are returned as lines of the format %META:\w+{.*}%)

• $searchString - the search string, in egrep format
• $web - The web/s to search in - string can have the same form as the web param of SEARCH
• \@topics - reference to a list of topics to search (if undef, then the store will search all topics in the specified web/webs.)
• \%option - reference to an options hash

The \%options hash may contain the following options:

• type - regex, keyword, query - defaults to regex
• casesensitive - false to ignore case (default true)
• files_without_match - true to return files only (default false). If files_without_match is specified, it will return on the first match in each topic (i.e. it will return only one match per topic, and will not return matching lines).
• TODO: topic, excludetopic and other params as per SEARCH

The return value is a reference to a hash which maps each matching topic name to a list of the lines in that topic that matched the search, as would be returned by 'grep'.

To iterate over the returned topics use:

    my $matches = Foswiki::Func::searchInWebContent( "Slimy Toad", $searchWeb, \@topics,
            { casesensitive => 0, files_without_match => 0 } );
    foreach my $topic (keys(%$matches)) {
         ...etc