Edgewall Software

Changes between Version 5 and Version 6 of 1.3/TracPlugins


Ignore:
Timestamp:
Aug 27, 2019, 1:08:41 AM (5 months ago)
Author:
Ryan J Ollos
Comment:

Minor edits.

Legend:

Unmodified
Added
Removed
Modified
  • 1.3/TracPlugins

    v5 v6  
    1717Packages built for a single project must use the egg
    1818format, as the wheel format (described below) is not
    19 supported by the setuptool loading mechanism. Build the `egg` file from the plugin source:
     19supported by the setuptools loading mechanism. Build the `egg` file from the plugin source:
    2020
    2121* Checkout or download and unpack the source.
     
    3030Make sure the web server has sufficient permissions to read the plugin egg and restart the web server. If you are running as a [TracStandalone "tracd" standalone server], restart tracd (i.e. kill the process and run again).
    3131
    32 Trac also searches for plugins installed in the shared plugins directory, see TracIni#GlobalConfiguration. This is a convenient way to share the installation of plugins across several, but not all, environments.
    33 
    34 '''Note''': the minor version number of the Python used to build the egg ''must'' match the minor version number of the Python running Trac. For example, if you are running Trac with Python 2.6, but build the egg with Python 2.7, the egg won't be recognized.
    35 
    36 '''Note''': in a multi-project setup, a pool of Python interpreter instances will be dynamically allocated to projects based on need; since plugins occupy a place in Python's module system, the first version of any given plugin to be loaded will be used for all projects. In other words, you cannot use different versions of a single plugin in two projects of a multi-project setup. It may be safer to install plugins for all projects (see below), and then enable them selectively on a project-by-project basis.
     32Trac also searches for plugins installed in the [TracIni#GlobalConfiguration global shared] plugins directory. This is a convenient way to share the installation of plugins across several, but not all, environments.
     33
     34'''Note''': The minor version number of the Python used to build the egg ''must'' match the minor version number of the Python running Trac. For example, if you are running Trac with Python 2.6, but build the egg with Python 2.7, the egg won't be recognized.
     35
     36'''Note''': In a multi-project setup, a pool of Python interpreters will be dynamically allocated to projects based on need. Since plugins occupy a place in Python's module system, the first version of any given plugin to be loaded will be used for all projects. In other words, you cannot use different versions of a plugin in different projects of a multi-project setup. Install plugins for all projects (see below) and enable them as needed for each project.
    3737
    3838==== Uninstalling
     
    5959The version can be specified, which can be useful if you don't want to install the latest:
    6060{{{#!sh
    61 $ pip install TracTags==0.9
     61$ pip install TracTags==0.10
    6262}}}
    6363
     
    9393}}}
    9494
    95 The name of the option is the plugin package name. This should be specified in the documentation of the plugin, but can also be easily discovered by looking at the source: look for a top-level directory that contains a file named `__init__.py`.
     95The name of the option is the plugin package name. This should be specified in the documentation of the plugin, but can also be discovered by looking at the source: it is usually the top-level directory name containing a file named `__init__.py`.
    9696
    9797Plugins can also be enabled from the [#Web-basedpluginadministration administration] page.
     
    151151== Web-based plugin administration
    152152
    153 The !WebAdmin interface offers limited support for plugin configuration through the web to users with `TRAC_ADMIN` permission:
    154 
    155 * en/disabling installed plugins
     153The admin page offers limited support for plugin configuration to users with `TRAC_ADMIN` permission:
     154
     155* en/dis-abling installed plugins
    156156* installing plugins by uploading them as eggs
    157157
     
    165165== Setting up the plugin cache
    166166
    167 Some plugins installed as eggs will need to be extracted by the Python egg's runtime (`pkg_resources`), so that their contents are actual files on the file system. The directory in which they are extracted defaults to `.python-eggs` in the home directory of the current user, which may or may not be a problem. You can, however, override the default location using the `PYTHON_EGG_CACHE` environment variable.
     167Some plugins installed as eggs will need to be extracted by the Python egg's runtime (`pkg_resources`), so that their contents are actual files on the file system. The directory to which they are extracted defaults to `.python-eggs` in the home directory of the current user, which may or may not be a problem. You can, however, override the default location using the `PYTHON_EGG_CACHE` environment variable.
    168168
    169169To do this from the Apache configuration, use the `SetEnv` directive:
     
    172172}}}
    173173
    174 This works whether you're using the [wiki:TracCgi CGI] or the [wiki:TracModPython mod_python] front-end. Put this directive next to where you set the path to the [wiki:TracEnvironment Trac environment], ie in the same `<Location>` block.
     174This works whether you're using the [TracCgi CGI] or the [TracModPython mod_python] front-end. Put this directive next to where you set the path to the [TracEnvironment Trac environment], i.e. in the same `<Location>` block.
    175175
    176176For example for CGI:
     
    193193'''Note''': !SetEnv requires the `mod_env` module, which needs to be activated for Apache. In this case the !SetEnv directive can also be used in the `mod_python` Location block.
    194194
    195 For [wiki:TracFastCgi FastCGI], you'll need to `-initial-env` option, or whatever is provided by your web server for setting environment variables.
     195For [TracFastCgi FastCGI], you'll need to `-initial-env` option, or whatever is provided by your web server for setting environment variables.
    196196
    197197'''Note''': if you already use -initial-env to set the project directory for either a single project or parent, you will need to add an additional -initial-env directive to the !FastCgiConfig directive:
     
    203203=== About hook scripts
    204204
    205 If you have set up some Subversion hook scripts that call the Trac engine, such as the post-commit hook script provided in the `/contrib` directory, make sure you define the `PYTHON_EGG_CACHE` environment variable within these scripts as well.
     205If you have Subversion hook scripts that invoke Trac, such as the post-commit hook script provided in the `/contrib` directory, make sure you define the `PYTHON_EGG_CACHE` environment variable within these scripts.
    206206
    207207== Writing Trac Plugins
     
    210210* [trac:TracDev Developer documentation]
    211211* [https://trac-hacks.org Examples on trac-hacks.org]
    212 * [trac:browser:branches/1.2-stable/sample-plugins sample-plugins]
     212* [trac:browser:branches/1.4-stable/sample-plugins sample-plugins]
    213213
    214214== Troubleshooting
     
    218218Python eggs have the Python version encoded in their filename. For example, `MyPlugin-1.0-py2.5.egg` is an egg for Python 2.5, and will '''not''' be loaded if you're running a different Python version (such as 2.4 or 2.6).
    219219
    220 Also, verify that the egg file you downloaded is indeed a .zip archive. If you downloaded it from a Trac site, chances are you downloaded the HTML preview page instead.
     220Also, verify that the egg file you downloaded is indeed a .zip archive. If you downloaded it from a Trac site, you may have downloaded the HTML preview page instead.
    221221
    222222=== Is the plugin enabled?
    223223
    224 If you install a plugin globally, ie ''not'' inside the `plugins` directory of the Trac project environment, you must explicitly enable it in [TracIni trac.ini]. Make sure that:
     224If you install a plugin globally, i.e. ''not'' inside the `plugins` directory of the Trac project environment, you must explicitly enable it in [TracIni trac.ini]. Make sure that:
    225225
    226226 * you added the necessary line(s) to the `[components]` section.
     
    229229 * the section name is `components`, not `component`.
    230230
    231 === Check the permissions on the .egg file
    232 
    233 Trac must be able to read the .egg file.
     231=== Check the permissions
     232
     233Trac must be able to read the .py file or package (.egg or .whl).
    234234
    235235=== Check the log files
     
    239239=== Verify you have the proper permissions
    240240
    241 Some plugins require you have special permissions in order to use them. !TracTags, for example, requires `TAGS_VIEW` permissions for the //Tags// navigation item to be added.
     241Some plugins require you have special permissions. !TracTags, for example, requires `TAGS_VIEW` permissions for the //Tags// navigation item to be added.
    242242
    243243=== Is the wrong version of the plugin loading?
    244244
    245 If you put your plugins inside plugins directories, and certainly if you have more than one project, you need to make sure that the correct version of the plugin is loading. Here are some basic rules:
    246 
    247 * Only one version of the plugin can be loaded for each running Trac server, ie each Python process. The Python namespaces and module list will be shared, and it cannot handle duplicates. Whether a plugin is `enabled` or `disabled` makes no difference.
     245If you put your plugins in one of the `plugins` directories, and certainly if you have more than one project, you need to make sure that the correct version of the plugin is loading. Here are some basic rules:
     246
     247* Only one version of the plugin can be loaded for each running Trac server, i.e. each Python process. The Python namespaces and module list will be shared, and it cannot handle duplicates. Whether a plugin is `enabled` or `disabled` makes no difference.
    248248* A globally installed plugin will override any version in the global or project plugins directories. A plugin from the global plugins directory will be discovered ''before'' any project plugins directory.
    249249* If your Trac server hosts more than one project (as with `TRAC_ENV_PARENT_DIR` setups), having two versions of a plugin in two different projects will give unpredicatable results. Only one of them will load, and the one loaded will be shared by both projects. Trac will load the first plugin found, usually from the project that receives the first request.
     
    252252=== If all of the above failed
    253253
    254 Okay, so the logs don't mention plugins, the egg is readable, the Python version is correct, ''and'' the egg has been installed globally (and is enabled in trac.ini)... and it ''still'' doesn't work or give any error messages or any other indication as to why. Hop on the [trac:IrcChannel IrcChannel] or [trac:MailingList].
     254See TracSupport.
    255255
    256256----
    257 See also TracGuide, [trac:PluginList plugin list], [trac:TracDev/ComponentArchitecture component architecture].
     257See also TracGuide, TracIni.