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TWiki PluginsAdd functionality to TWiki with readily available plugins; create plugins based on APIsOn this page:
OverviewYou can add plugins to extend TWiki functionality, without altering the core code. A plug-in approach lets you:
web.
TWiki plugins are developed and contributed by interested members of the community. Plugins are provided on an 'as is' basis; they are not a part of TWiki, but are independently developed and maintained.
Relevant links on TWiki.org:
Installing PluginsThe TWiki:Plugins web on TWiki.org is the repository for TWiki plugins. Each plugin such as the TWiki:Plugins.ChartPlugin has a topic with user guide, step-by-step installation instructions, a detailed description of any special requirements, version details, and a working example for testing. There's usually a number of other related topics, such as a developers page, and an appraisal page.
Most TWiki plugins are packaged so that they can be installed and upgraded using the configure script. To install a plugin, open up the Extensions tab, follow the "Find More Extensions" link, and follow the instructions. A plugin needs to be enabled after installation.
Plugins can also be installed manually: Download the zip or tgz package of a TWiki plugin from the TWiki.org repository, upload it to the TWiki server, unpack it, and follow the installation instructions found in the plugin topic on TWiki.org.
Special Requirements: Some plugins need certain Perl modules to be pre-installed on the host system. Plugins may also use other resources, like graphics, other modules, applications, and templates. You should be able to find detailed instructions in the plugin's documentation. Use the package manager of the server OS (yum, apt-get, rpm, etc) to install dependent libraries.
If available, install CPAN (Comprehensive Perl Archive Network) libraries with the OS package manager. For example, to install IO::Socket::SSL on Fedora/RedHat/CentOS, run yum install perl-IO-Socket-SSL. CPAN modules can also be installed natively, see TWiki:TWiki.HowToInstallCpanModules.
On-Site PretestingIf you have a mission critical TWiki installation and you are concerned about installing new plugins, you can test new plugins before making them available by creating a second test TWiki installation, and test the plugin there. It is also possible to configure this test TWiki to use the live data. You can allow selected users access to the test area. Once you are satisfied that it won't compromise your primary installation, you can install it there as well. InstalledPlugins shows which plugins are: 1) installed, 2) loading properly, and 3) what TWiki:Codev.PluginHandlers they invoke. Any failures are shown in the Errors section. The %FAILEDPLUGINS% variable can be used to debug failures. You may also want to check your webserver error log and the various TWiki log files.
Some Notes on Plugin PerformanceThe performance of the system depends to some extent on the number of plugins installed and on the plugin implementation. Some plugins impose no measurable performance decrease, some do. For example, a Plugin might use many Perl libraries that need to be initialized with each page view (unless you run mod_perl). You can only really tell the performance impact by installing the plugin and by measuring the performance with and without the new plugin. Use the TWiki:Plugins.PluginBenchmarkAddOn, or test manually with the Apache ab utility. Example on Unix:time wget -qO /dev/null /bin/view/TWiki/AbcPlugin
 If you need to install an "expensive" plugin, but you only need its functionality only in a subset of your data, you can disable it elsewhere by defining the %DISABLEDPLUGINS% TWiki variable.
Define DISABLEDPLUGINS to be a comma-separated list of names of plugins to disable. Define it in Main.TWikiPreferences to disable those plugins everywhere, in the WebPreferences topic to disable them in an individual web, or in a topic to disable them in that topic. For example,
* Set DISABLEDPLUGINS = SpreadSheetPlugin, EditTablePlugin Managing Installed PluginsSome plugins require additional settings or offer extra options that you have to select. Also, you may want to make a plugin available only in certain webs, or temporarily disable it. And may want to list all available plugins in certain topics. You can handle all of these management tasks with simple procedures:Enabling/Disabling PluginsPlugins can be enabled and disabled with the configure script in the Plugins section. An installed plugin needs to be enabled before it can be used.Plugin Evaluation OrderBy default, TWiki executes plugins in alphabetical order on plugin name. It is possible to change the order, for example to evaluate database variables before the spreadsheet CALCs. This can be done with{PluginsOrder} in the plugins section of configure.
Plugin-Specific SettingsPlugins can be configured with 1. preferences settings and/or 2. with configure settings. Older plugins use plugin preferences settings defined in the plugin topic, which is no longer recommended. 1. Use preferences settings: Adinistrators can set plugin-specific settings in the local site preferences at Main.TWikiPreferences and users can overload them at the web level and page level. This approach is recommended if users should be able to overload settings. For security this is not recommended for system settings, such as a path to an executable. By convention, preferences setting names start with the plugin name in all caps, and an underscore. For example, to set the cache refresh period of the TWiki:Plugins.VarCachePlugin, add this bullet in Main.TWikiPreferences
%<pluginname>_<setting>%, such as %VARCACHEPLUGIN_REFRESH%.
To learn how this is done, use the TWiki:Plugins.VarCachePlugin documentation and Perl plugin code as a reference.
2. Use configure settings:
The administrator can set plugin settings in the configure interface. Recommended if only site administrators should be able to change settings. Chose this option to set sensitive or dangerous system settings, such as passwords or path to executables. To define plugin-specific configure settings,
documentation and Perl plugin code as a reference.
In either case, define a SHORTDESCRIPTION setting in two places:
our $NO_PREFS_IN_TOPIC = 1;
Listing Active PluginsPlugin status variables let you list all active plugins wherever needed. This site is running TWiki version TWiki-6.1.0, Mon, 16 Jul 2018, build 30610, plugin API version 6.10
On this TWiki site, the enabled plugins are: SpreadSheetPlugin, BackupRestorePlugin, ColorPickerPlugin, CommentPlugin, DatePickerPlugin, EditTablePlugin, HeadlinesPlugin, InterwikiPlugin, JQueryPlugin, PreferencesPlugin, SetGetPlugin, SlideShowPlugin, SmiliesPlugin, TWikiSheetPlugin, TablePlugin, TagMePlugin, TimeSincePlugin, TinyMCEPlugin, TwistyPlugin, WatchlistPlugin, WysiwygPlugin.
|
| Plugin | Errors |
|---|---|
| SpreadSheetPlugin | none |
| BackupRestorePlugin | none |
| ColorPickerPlugin | none |
| CommentPlugin | none |
| DatePickerPlugin | none |
| EditTablePlugin | none |
| HeadlinesPlugin | none |
| InterwikiPlugin | none |
| JQueryPlugin | none |
| PreferencesPlugin | none |
| SetGetPlugin | none |
| SlideShowPlugin | none |
| SmiliesPlugin | none |
| TWikiSheetPlugin | none |
| TablePlugin | none |
| TagMePlugin | none |
| TimeSincePlugin | none |
| TinyMCEPlugin | none |
| TwistyPlugin | none |
| WatchlistPlugin | none |
| WysiwygPlugin | none |
| Handler | Plugins |
|---|---|
| afterEditHandler | WysiwygPlugin |
| afterRenameHandler | TagMePlugin WatchlistPlugin |
| afterSaveHandler | TagMePlugin WatchlistPlugin |
| beforeCommonTagsHandler | EditTablePlugin PreferencesPlugin TWikiSheetPlugin TwistyPlugin WysiwygPlugin |
| beforeEditHandler | TinyMCEPlugin WysiwygPlugin |
| beforeMergeHandler | WysiwygPlugin |
| beforeSaveHandler | CommentPlugin WatchlistPlugin WysiwygPlugin |
| commonTagsHandler | SpreadSheetPlugin BackupRestorePlugin CommentPlugin EditTablePlugin JQueryPlugin SlideShowPlugin SmiliesPlugin TWikiSheetPlugin |
| initPlugin | SpreadSheetPlugin BackupRestorePlugin ColorPickerPlugin CommentPlugin DatePickerPlugin EditTablePlugin HeadlinesPlugin InterwikiPlugin JQueryPlugin PreferencesPlugin SetGetPlugin SlideShowPlugin SmiliesPlugin TWikiSheetPlugin TablePlugin TagMePlugin TimeSincePlugin TinyMCEPlugin TwistyPlugin WatchlistPlugin WysiwygPlugin |
| modifyHeaderHandler | WysiwygPlugin |
| postRenderingHandler | PreferencesPlugin WysiwygPlugin |
| preRenderingHandler | InterwikiPlugin SmiliesPlugin TablePlugin |
lib/TWiki/Func.pm) describes all the interfaces available to plugins. Plugins should only use the interfaces described in this module.
Note: If you use other core functions not described in Func.pm, you run the risk of creating security holes. Also, your plugin will likely break and require updating when you upgrade to a new version of TWiki.
lib/TWiki/Plugins/EmptyPlugin.pm module.
# from all lines of the callback.
helps you decide which rendering handler to use.
eval block like this:eval { require IPC::Run } return "<font color=\"red\">SamplePlugin: Can't load required modules ($@)</font>" if $@;
lib/TWiki/Plugins/BathPlugin/.
$NO_PREFS_IN_TOPIC in your plugin package as that will stop TWiki from reading the plugin topic for every page. Use Config.spec or preferences settings instead. (See details).
$VERSION variable. This should be an integer, or a subversion version id.
initPlugin handler should check all dependencies and return 1 if the initialization is OK or 0 if something went wrong. initPlugin handler).
$TWiki::Plugins::VERSION in the TWiki::Plugins module contains the TWiki plugin API version, currently 6.10. %PLUGINVERSION{}% variable to query the plugin API version or the version of installed plugins.
%TWiki::cfg hash than adding it as preferences in the plugin topic. configure describes the steps
has an example
can help you with this
MyFirstPlugin.pm
MyFirstPlugin.txt
MyFirstPlugin topic. Other needed Perl code is best placed in a lib/TWiki/Plugins/MyFirstPlugin/ directory.
The plugin API handles the details of connecting your Perl module with main TWiki code. When you're familiar with the Plugin API, you're ready to develop plugins.
The TWiki:Plugins.BuildContrib module provides a lot of support for plugins development, including a plugin creator, automatic publishing support, and automatic installation script writer. If you plan on writing more than one plugin, you probably need it.
lib/TWiki/Plugins/EmptyPlugin.pm to <name>Plugin.pm. The EmptyPlugin.pm module contains mostly empty functions, so it does nothing, but it's ready to be used. Customize it. Refer to the Plugin API specs for more information.
If your plugin uses its own modules and objects, you must include the name of the plugin in the package name. For example, write Package MyFirstPlugin::Attrs; instead of just Package Attrs;. Then call it using:
use TWiki::Plugins::MyFirstPlugin::Attrs; $var = MyFirstPlugin::Attrs->new();
and: MyFirstPlugin, press enter and create the new topic
. This is important because links should work properly in a plugin topic installed on any TWiki, not just on TWiki.org.
OUTLINE: Doc Topic Contents
Check the plugins web on TWiki.org for the latest plugin doc topic template. Here's a quick overview of what's covered: Syntax Rules: <Describe any special text formatting that will be rendered.>" Example: <Include an example of the plugin in action. Possibly include a static HTML version of the example to compare if the installation was a success!>" Plugin Settings: <Description and settings for custom plugin %VARIABLES%, and those required by TWiki.>" Plugin Installation Instructions: <Step-by-step set-up guide, user help, whatever it takes to install and run, goes here.>" Plugin Info: <Version, credits, history, requirements - entered in a form, displayed as a table. Both are automatically generated when you create or edit a page in the TWiki:Plugins
is a powerful build environment that is used by the TWiki project to build TWiki itself, as well as many of the plugins. You don't have to use it, but it is highly recommended!
If you don't want (or can't) use the BuildContrib, then a minimum plugin release consists of a Perl module with a WikiName that ends in Plugin, ex: MyFirstPlugin.pm, and a documentation page with the same name(MyFirstPlugin.txt).
lib/TWiki/Plugins/MyFirstPlugin.pm
data/TWiki/MyFirstPlugin.txt
pub/TWiki/MyFirstPlugin/uparrow.gif [a required graphic]
MyFirstPlugin.zip) and add the entire directory structure from Step 1. The archive should look like this: lib/TWiki/Plugins/MyFirstPlugin.pm
data/TWiki/MyFirstPlugin.txt
pub/TWiki/MyFirstPlugin/uparrow.gif
to measure your TWiki:Plugins.PluginBenchmarks. The data is needed as part of the Documentation Topic.
See also Hints on Writing Fast Plugins.
web. All plugins submitted to TWiki.org are available for download and further development in TWiki:Plugins/PluginPackage.
Publish your plugin by following these steps: : MyFirstPlugin
MyFirstPlugin.zip
Dev, ex: MyFirstPluginDev. This is the discussion page for future development. (User support for plugins is handled in TWiki:Support.)
(optional)
Once you have done the above steps once, you can use the BuildContrib to upload updates to your plugin.
Thank you very much for sharing your plugin with the TWiki community 
TWiki::Func::getWorkArea() function, which gives you a persistent directory where you can store data files. By default they will not be web accessible. The directory is guaranteed to exist, and to be writable by the webserver user. For convenience, TWiki::Func::storeFile() and TWiki::Func::readFile() are provided to persistently store and retrieve simple data in this area.
TWiki::Func::saveAttachment() function to store the data.
Recommendation for file name: _GaugePlugin_img123.gif
TWiki::Func::saveAttachment() function to store the data.
Recommendation for file names in plugin attachment area: _Main_roundedge-ul.gif
configure configure rather than trying to use TWiki preferences variables. These extensions use Config.spec files to publish their configuration requirements.
Config.spec files are read during TWiki configuration. Once a Config.spec has defined a configuration item, it is available for edit through the standard configure interface. Config.spec files are stored in the 'plugin directory' e.g. lib/TWiki/Plugins/BathPlugin/Config.spec.
Config.spec file Config.spec file for an extension starts with the extension announcing what it is:
# ---+ Extensions # ---++ BathPlugin # This plugin senses the level of water in your bath, and ensures the plug # is not removed while the water is still warm.This is followed by one or more configuration items. Each configuration item has a type, a description and a default. For example:
# **SELECT Plastic,Rubber,Metal**
# Select the plug type
$TWiki::cfg{BathPlugin}{PlugType} = 'Plastic';
# **NUMBER**
# Enter the chain length in cm
$TWiki::cfg{BathPlugin}{ChainLength} = 30;
# **BOOLEAN EXPERT**
# Set this option to 0 to disable the water temperature alarm
$TWiki::cfg{BathPlugin}{TempSensorEnabled} = 1;
The type (e.g. **SELECT** ) tells configure to how to prompt for the value. It also tells configure how to do some basic checking on the value you actually enter. All the comments between the type and the configuration item are taken as part of the description. The configuration item itself defines the default value for the configuration item. The above spec defines the configuration items $TWiki::cfg{BathPlugin}{PlugType}, $TWiki::cfg{BathPlugin}{ChainLength}, and $TWiki::cfg{BathPlugin}{TempSensorEnabled} for use in your plugin. For example,
if( $TWiki::cfg{BathPlugin}{TempSensorEnabled} && $curTemperature > 50 ) {
die "The bathwater is too hot for comfort";
}
The Config.spec file is read by configure, which then writes LocalSite.cfg with the values chosen by the local site admin.
A range of types are available for use in Config.spec files:
| BOOLEAN | A true/false value, represented as a checkbox |
| COMMAND length | A shell command |
| LANGUAGE | A language (selected from {LocalesDir} |
| NUMBER | A number |
| OCTAL | An octal number |
| PASSWORD length | A password (input is hidden) |
| PATH length | A file path |
| PERL | A perl structure, consisting of arrays and hashes |
| REGEX length | A perl regular expression |
| SELECT choices | Pick one of a range of choices |
| SELECTCLASS root | Select a perl package (class) |
| STRING length | A string |
| URL length | A url |
| URLPATH length | A relative URL path |
| EXPERT | means this an expert option |
| M | means the setting is mandatory (may not be empty) |
| H | means the option is not visible in configure |
lib/TWiki.spec for many more examples.
Config.spec files for non-plugin extensions are stored under the Contrib directory instead of the Plugins directory.
Note that from TWiki 5.0 onwards, CGI scripts (in the TWiki bin directory) provided by extensions must also have an entry in the Config.spec file. This entry looks like this (example taken from PublishContrib)
# **PERL H**
# Bin script registration - do not modify
$TWiki::cfg{SwitchBoard}{publish} = [ "TWiki::Contrib::Publish", "publish", { publishing => 1 } ];
PERL specifies a perl data structure, and H a hidden setting (it won't appear in configure). The first field of the data value specifies the class where the function that implements the script can be found. The second field specifies the name of the function, which must be the same as the name of the script. The third parameter is a hash of initial context settings for the script.
TWiki:TWiki/SpecifyingConfigurationItemsForExtensions has supplemental documentation on configure settings.
Dev, such as MyFirstPluginDev. The plugin development topic is a great resource to discuss feature enhancements and to get feedback from the TWiki community.
Tip: Plugins can be written to be compatible with older and newer TWiki releases. This can be done also for plugins using unofficial TWiki internal functions of an earlier release that no longer work on the latest TWiki codebase.
Here is an example; the TWiki:TWiki.TWikiPluginsSupplement#MaintainPlugins has more details.
if( $TWiki::Plugins::VERSION >= 1.1 ) {
@webs = TWiki::Func::getListOfWebs( 'user,public' );
} else {
@webs = TWiki::Func::getPublicWebList( );
}
TWiki::Plugins version in which the handler was first deprecated. For example, if we need to define the endRenderingHandler for compatibility with TWiki::Plugins versions before 1.1, we would add this to the plugin:
package TWiki::Plugins::SinkPlugin;
use vars qw( %TWikiCompatibility );
$TWikiCompatibility{endRenderingHandler} = 1.1;
If the currently-running TWiki version is 1.1 or later, then the handler will not be called and the warning will not be issued. TWiki with versions of TWiki::Plugins before 1.1 will still call the handler as required.
Related Topics: DeveloperDocumentationCategory, AdminDocumentationCategory, TWiki:TWiki.TWikiPluginsSupplement
-- Contributors: TWiki:Main.PeterThoeny, TWiki:Main.AndreaSterbini, TWiki:Main.MikeMannix, TWiki:Main.CrawfordCurrie, TWiki:Main.ArthurClemens, TWiki:Main.WillNorris