29.1. QGIS Plugins

QGIS has been designed with a plugin architecture. This allows many new features and functions to be easily added to the application. Some of the features in QGIS are actually implemented as plugins.

29.1.1. Core and External plugins

QGIS plugins are implemented either as Core Plugins or External Plugins.

Core Plugins are maintained by the QGIS Development Team and are automatically part of every QGIS distribution. They are written in one of two languages: C++ or Python.

Most of External Plugins are currently written in Python. They are stored either in the ‘Official’ QGIS Repository at https://plugins.qgis.org/plugins/ or in external repositories and are maintained by the individual authors. Detailed documentation about the usage, minimum QGIS version, home page, authors, and other important information are provided for the plugins in the Official repository. For other external repositories, documentation might be available with the external plugins themselves. External plugins documentation is not included in this manual.

To install or activate a plugin, go to Plugins menu and select showPluginManager Manage and install plugins…. Installed external python plugins are placed under the python/plugins folder of the active user profile path.

Paths to Custom C++ plugins libraries can also be added under Settings ► Options ► System.

29.1.2. The Plugins Dialog

29.1.2.1. The Settings tab

At the bottom of the left panel, the transformSettings Settings tab is the main place you can configure which plugins can be displayed in your application. You can use the following options:

  • checkbox Check for Updates on Startup. Whenever an installed plugin has update available, QGIS will inform you Every Time QGIS starts, Once a Day, Every 3 Days, Every Week, Every 2 Weeks or Every month.

  • checkbox Show also Experimental Plugins. QGIS will show you plugins in early stages of development, which are generally unsuitable for production use. For these plugins, you can install either the stable or the experimental version, and at any moment switch from one to the other.

  • checkbox Show also Deprecated Plugins. These plugins are usually unmaintained because they have replacement functions in QGIS, a lack of maintainers, they rely on functions that are no longer available in QGIS… They are generally unsuitable for production use and appear grayed in the plugins list.

By default, in the Plugin Repositories section, QGIS provides you with its official plugin repository with the URL https://plugins.qgis.org/plugins/plugins.xml?qgis=version (where <version> represents the exact QGIS version you are running). To add external author repositories, click symbologyAdd Add… and fill in the Repository Details form with a name and the URL. The URL can be of http:// or file:// protocol type.

The default QGIS repository is an open repository and you don’t need any authentication to access it. You can however deploy your own plugin repository and require an authentication (basic authentication, PKI). You can get more information on QGIS authentication support in Authentication chapter.

If you do not want one or more of the added repositories, they can be disabled from the Settings tab via the symbologyEdit Edit… button, or completely removed with the symbologyRemove Delete button.

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Fig. 29.1 The transformSettings Settings tab

29.1.2.2. Browsing the plugins

The tabs

The upper tabs in the Plugins dialog provide you with lists of plugins based on their install, creation or update status. Depending on the plugins settings, available tabs can be:

  • showPluginManager All: shows all the available plugins in the enabled repositories

  • pluginInstalled Installed: shows both the plugins you installed and the core plugins that are installed by default and you can not uninstall

  • plugin Not installed: shows uninstalled or not yet installed plugins in the enabled repositories

  • plugin-new New: shows plugins released since the last Check for Updates on Startup

  • plugin-upgrade Upgradeable: shows installed plugins that have published a more recent version in the repository

  • pluginIncompatible Invalid: shows all installed plugins that are currently broken for any reason (missing dependency, errors while loading, incompatible functions with QGIS version…)

At the top of the tabs, a Search function helps you find any plugin using metadata information (author, name, description, tag,…).

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Fig. 29.2 Searching a plugin from the showPluginManager All tab

The Plugins

Select a plugin and you will have some metadata displayed in the right panel:

  • information on whether the plugin is experimental or has an experimental version available (if Show also Experimental Plugins is checked)

  • summary and description

  • rating vote(s) (you can vote for your preferred plugin!)

  • tags

  • some useful links to the home page, tracker and code repository

  • author(s)

  • version(s) available with link to download page in the repository, or path to local folder for installed plugins

The Plugin Manager dialog allows you to interact with the latest version of the plugins. When enabled, the experimental version can be shown only if it is more recent than the latest stable version. Depending on the active tab, whether the selected plugin is installed, you will be given some of the following options:

  • Install: installs the latest stable version of the selected plugin

  • Install Experimental Plugin: installs the experimental version of the selected plugin

  • Reinstall Plugin: installs the same stable version of the plugin e.g. after it has failed to load

  • Reinstall Experimental Plugin: installs the same stable version of the plugin e.g. after it has failed to load

  • Upgrade Plugin: upgrades selected plugin to its latest stable version

  • Upgrade Experimental Plugin: upgrades selected plugin to its experimental version

  • Upgrade All: upgrades all installed plugins to their more recent stable or experimental version (depending on whether their previously installed version was stable or experimental).

  • Downgrade Plugin: moves from the experimental version of the plugin to its previous stable version

  • Downgrade Experimental Plugin: moves from an experimental version of the plugin to its latest published experimental version. This may occur when playing with a not yet published version.

  • Uninstall Plugin: removes the installed plugin from the user profile

An installed plugin displays a checkbox checkbox on its left. Uncheck it to temporarily deactivate the plugin.

Right-click on a plugin in the list and you will be able to sort the plugins list by various metadata. The new order applies to all the tabs. Sort options are:

  • Sort by Name

  • Sort by Downloads

  • Sort by Vote

  • Sort by Status

  • Sort by Date Created

  • Sort by Date Updated

29.1.2.3. The Install from ZIP tab

The installPluginFromZip Install from ZIP tab provides a file selector widget to import plugins in a zipped format, e.g. plugins downloaded directly from their repository. Encrypted files are supported.

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Fig. 29.3 The installPluginFromZip Install from zip tab