<li><a href="#Preinstalled Plugins"> Preinstalled Plugins</a></li>
<li><a href="#Installing Plugins"> Installing Plugins</a><ul>
<li><a href="#On-Site Pretesting"> On-Site Pretesting</a></li>
+ <li><a href="#A Note on Plugin Performance"> A Note on Plugin Performance</a></li>
</ul>
</li>
<li><a href="#Managing Plugins"> Managing Plugins</a><ul>
<li><a href="#The TWiki Plugin API"> The TWiki Plugin API</a><ul>
<li><a href="#Available Core Functions"> Available Core Functions</a></li>
<li><a href="#Predefined Hooks"> Predefined Hooks</a></li>
+ <li><a href="#Hints on Writing Fast Plugins"> Hints on Writing Fast Plugins</a></li>
<li><a href="#Plugin Version Detection"> Plugin Version Detection</a></li>
</ul>
</li>
## <a name="Preinstalled Plugins"></a> Preinstalled Plugins
-TWiki comes with three Plugins as part of the standard installation.
+TWiki comes with a set of Plugins as part of the standard installation.
-- **[[DefaultPlugin]]** optionally handles some legacy variables from older versions of TWiki. You can control this option from [[TWikiPreferences]]. (Perl programmers can also [[add rules|Main/WebHome#DefaultPluginAlt]] for simple custom processing.)
-
-- **[[EmptyPlugin]]** is a fully functional module, minus active code; it does nothing and serves as a template for new Plugin development.
-
-- **[[InterwikiPlugin]]** is preinstalled but can be disabled or removed. Use it for shorthand linking to remote sites, ex: `TWiki:Plugins` expands to TWiki:Plugins on TWiki.org. You can edit the predefined set of of Wiki-related sites, and add your own.
+- [[DefaultPlugin]]: Optionally handles some legacy variables from older versions of TWiki. You can control this option from [[TWikiPreferences]]. (Perl programmers can also [[add rules|Main/WebHome#DefaultPluginAlt]] for simple custom processing.)
+- [[EmptyPlugin]]: Is a fully functional module, minus active code; it does nothing and serves as a template for new Plugin development.
+- [[InterwikiPlugin]]: Use it for shorthand linking to remote sites, ex: `TWiki:Plugins` expands to TWiki:Plugins on TWiki.org. You can edit the predefined set of of Wiki-related sites, and add your own.
+- [[EditTablePlugin]]: %EDITTABLEPLUGIN\_SHORTDESCRIPTION%
+- [[RenderListPlugin]]: %RENDERLISTPLUGIN\_SHORTDESCRIPTION%
+- [[SlideShowPlugin]]: %SLIDESHOWPLUGIN\_SHORTDESCRIPTION%
+- [[SmiliesPlugin]]: %SMILIESPLUGIN\_SHORTDESCRIPTION%
+- [[SpreadSheetPlugin]]: %SPREADSHEETPLUGIN\_SHORTDESCRIPTION%
+- [[TablePlugin]]: %TABLEPLUGIN\_SHORTDESCRIPTION%
<a name="InstallPlugin"></a>
To test new Plugins on your installation before making them public, you may want to use one of these two approaches:
- **Method 1:** Safely test on-the-fly by creating separate Production and Test branches in your live TWiki installation.
- - **Duplicate** the `twiki/bin` and `twiki/lib` directories for the Test version, adjusting the paths in the new `lib/TWiki.cfg`, the `twiki/data`; the `twiki/templates` and `twiki/pub` directories are shared.
+ - **Duplicate** the `twiki/bin` and `twiki/lib` directories for the Test version, and adjust the paths in the new `lib/TWiki.cfg`. The following directories are shared: `twiki/data`, `twiki/templates` and `twiki/pub`.
- **Test** Plugins and other new features in the Test installation until you're satisfied.
- %X% If you modify topics using the new features, live users will likely see unfamiliar new META tags showing up on their pages - to avoid this, create and edit test-only topics to try out new features.
- **Copy** the modified files to the Production installation. You can update a TWiki installation live and users won't even notice.
-- **Method 2:** List the Plugin under `Test` in the `DISABLEDPLUGINS` variable in [[TWikiPreferences]]. Redefine the `DISABLEDPLUGINS` variable in the Test web and do the testing there.
+- **Method 2:** List the Plugin being tested in the `DISABLEDPLUGINS` variable in [[TWikiPreferences]]. Redefine the `DISABLEDPLUGINS` variable in the `Sandbox` web and do the testing there.
+
+### <a name="A Note on Plugin Performance"></a> A Note on Plugin Performance
+
+The performance of the system depends on the number of Plugins installed and on the Plugin implementation. Some Plugins impose no measurable performance decrease, some do. For example, `outsidePREHandler` is an expensive callback function, or a Plugin might use many Perl libraries that need to be initialized with each page view (unless you run mod\_perl). It is recommended to measure the performance with and without a new Plugin. Example for Unix:%BR% `time wget -qO /dev/null http://www.dementia.org/twiki//view/TWiki/AbcPlugin`
+
+In case you need to install an "expensive" Plugin and you need its functionality only in one web you can place the Plugin topic into that web. TWiki will initialize the Plugin only if the Plugin topic is found (which won't be the case for other webs.)
## <a name="Managing Plugins"></a> Managing Plugins
### <a name="Available Core Functions"></a> Available Core Functions
-The `lib/TWiki/Func.pm` implements ALL official Plugin functions. Plugins should ONLY use functions published in this module.
+The [[TWikiFuncModule]] (`lib/TWiki/Func.pm`) implements ALL official Plugin functions. Plugins should ONLY use functions published in this module.
%X% If you use functions not 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.
-- For best performance, enable only the functions you really need. NOTE: `outsidePREHandler` and `insidePREHandler` are particularly expensive.
-
### <a name="Predefined Hooks"></a> Predefined Hooks
In addition to TWiki core functions, Plugins can use **predefined hooks**, or **call backs**, listed in the `lib/TWiki/Plugins/EmptyPlugin.pm` module.
- All but the initPlugin are disabled. To enable a call back, remove `DISABLE_` from the function name.
+- For best performance, enable only the functions you really need. NOTE: `outsidePREHandler` and `insidePREHandler` are particularly expensive.
+
+Most Plugins use either the `commonTagsHandler` or `startRenderingHandler` for rendering tasks:
+
+- `commonTagsHandler:` Use it to expand `%XYZPLUGIN%` and `%XYZPLUGIN{...}%` variables
+- `startRenderingHandler:` Use it for your own rendering rules or to overload TWiki's internal rendering like `[[links]]`
+
+TWiki:Codev/StepByStepRenderingOrder helps you decide which rendering handler to use.
+
+### <a name="Hints on Writing Fast Plugins"></a> Hints on Writing Fast Plugins
+
+- Delay the Plugin initialization to the actual function which is handling the tag. This way all the expensive initialization is done only when needed.
+- For example, use an `eval` block like:%BR% `eval { require IPC::Run }` %BR% `return "<font color=\"red\">SamplePlugin: Can't load required modules ($@)</font>" if $@;`
+- You could return errors as strings to show what happened
+- You can use a flag to avoid running the initialization twice
### <a name="Plugin Version Detection"></a> Plugin Version Detection
### <a name="Creating the Perl Module"></a> Creating the Perl Module
-Copy file `lib/TWiki/Plugins/EmptyPlugin.pm` to `<name>Plugin.pm`. `EmptyPlugin.pm` contains no executable code, so it does nothing, but it's ready to be used. Customize it. Refer to the [[Plugin API|Main/WebHome#PluginAPI]] specs for more information.
+Copy file `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|Main/WebHome#PluginAPI]] 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();
<a name="CreatePluginTopic"></a>
The Plugin documentation topic contains usage instructions and version details. It serves the Plugin files as [[FileAttachments]] for downloading. (The doc topic is also included _in_ the [[distribution package|Main/WebHome#CreatePluginPackage]].) To create a documentation topic:
-1. **Copy** the Plugin topic template from [[EmptyPlugin]]. To copy the text, go to the page and:
- - click Edit
+1. **Copy** the Plugin topic template from TWiki.org. To copy the text, go to TWiki:Plugins/PluginPackage and:
+ - enter the Plugin name in the "How to Create a Plugin" section
+ - click Create
- select all in the Edit box & copy
- Cancel the edit
- - paste & save as a text file or new topic on your site
-2. **Customize** the template for your Plugin; you'll probably want to post a working version on your local TWiki site.
-3. **Save** your topic as a text file, for use in [[packaging|Main/WebHome#CreatePluginPackage]] and [[publishing|Main/WebHome#PublishPlugin]] your Plugin.
+ - go back to your site to the TWiki web
+ - In the [[GoBox]] enter your Plugin name, for example `MyFirstPlugin`, press enter and create the new topic
+ - paste & save new Plugin topic on your site
+2. **Customize** your Plugin topic.
+ - In case you plan to publish your Plugin at TWiki.org, use Interwiki names for author names, like TWiki:Main/admin.
+3. **Save** your topic, for use in [[packaging|Main/WebHome#CreatePluginPackage]] and [[publishing|Main/WebHome#PublishPlugin]] your Plugin.
> **OUTLINE: Doc Topic Contents**
>
> <br />
>
-> Check
->
-> [[EmptyPlugin]]
->
-> on TWiki.org for the latest Plugin doc topic template. Here's a quick overview of what's covered:
+> 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._>"
>
-> **MyFirstPlugin Settings:** <_Description and settings for custom Plugin %VARIABLES%, and those required by TWiki._>"
->
-> **Plugins Preferences** <_If user settings are needed, explain... Entering valuse works exactly like [[TWikiPreferences]] and [[WebPreferences]]: six (6) spaces and then:_>"
+> **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!_>"
>
-> - - **Set <_EXAMPLE = value added_>**
+> **Plugin Global Settings:** <_Description and settings for custom Plugin %VARIABLES%, and those required by TWiki._>"
>
-> **How-to Instructions:** <_Step-by-step set-up guide, user help, whatever it takes to install and run, goes here._>"
+> - **Plugins Preferences** <_If user settings are needed, explain... Entering values works exactly like [[TWikiPreferences]] and [[WebPreferences]]: six (6) spaces and then:_>"
+> - **Set <_EXAMPLE = value added_>**
>
-> **Test Example:** <_Include an example of the Plugin in action: if it works, the installation was a success!_>"
+> **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 web._>"
2. **Attach** the distribution zip file to the topic, ex: `MyFirstPlugin.zip`
3. **Link** from the doc page to a new, blank page named after the Plugin, and ending in `Dev`, ex: `MyFirstPluginDev`. This is the discussion page for future development. (User support for Plugins is handled in TWiki:Support.)
--- [[AndreaSterbini]] - 29 May 2001 <br /> -- [[MikeMannix]] - 01 Sep 2001 <br /> -- [[PeterThoeny]] - 14 Sep 2001 <br />
+-- [[AndreaSterbini]] - 29 May 2001 <br /> -- [[PeterThoeny]] - 11 Dec 2003 <br /> -- [[MikeMannix]] - 03 Dec 2001