In order to customize and update GroIMP, the software comes with a plugin manager, which allows user to install, update or remove plugins.

By default the available plugins are loaded from a Repository provided by the GroIMP developer team (a online version can be found [[https://grogra.gitlab.io/groimp-utils/plugin_web_explorer/ | here]], yet it is easily possible to add an own list (see [[dev-guide:plugins|here]]). 

====== GUI ======


The easiest way to use the Plugin Manager is the Graphical user interface, which can be found in GroIMP under ''help/plugin manager''.{{ :user-guide:pluginmanagergui.png?nolink&600 |}}

The view for installed plugins and available plugins and updates is the same, all have the plugins of their category in a list on the left and a description of this plugin if selected on the right. Every change is listed in the text filed below for reviewing.
To install a available plugin or to upgrade a plugin the box next to it needs to be checked. 
For the installed plugins a three way selection is possible: if their box is checked with a check mark they stay installed, if the box is not checked they are removed and if the box is checked with a small square they are deactivated but not removed. 

On the last tab "Repositories" different sources for plugins can be added or selected, for further info see [[dev-guide:plugins|here]]). 

===== Deleting/ Deactivating plugins =====

1. The parameter file: GroIMP can load options as parameters from either: the default file (in ~/.grogra.de-platform/groimp.properties) or from a file given when starting groimp: "java -jar core.jar -t "path/to/perfs.properties".
The preference file is loaded when groimp starts and its content is used instead of java preferences when an option is queried in groimp. The option name follow the complete name of its registry path (I will provide a list of all option and their paths in the wiki). But for example the option useJRT can be defined as :
/de/grogra/options/rgg/javaimport/useJRT=true
  2. The plugin manager is accessible from the GUI under "Help>Plugin manager". Its goal is to help install/ remove/ update groimp plugins. So users can get small fixes in plugins without having to re download /reinstall a whole new groimp version.
And (maybe?) if users create new plugins and decide to share them, It could make them available for all other users.
From the plugin manager GUI, you can "install", "update", "disable", "remove" plugins.
install will try to download it from the given source then dump it in the selected path (selected in the options/ by default ~/.grogra.de-platform/plugins).
update: each plugin display its available versions. By selecting a different version you can upgrade/downgrade a plugin. This will download the new version from the given source, extract it under the plugin path, and remove the old version.
disable is more usefull for me to debug. It set some groimp option to load the given plugin as disabled. They are then not usable from groimp. But they are not removed. It adds the option under the currently used property file (either one passed with "-t" or the default one).
remove simply delete the plugin. It removes it from the computer (so be careful). For groimp instances where the installation path is not writable (usually on windows if you don't run groimp in admin) then, there is an option in groimp to "blacklist" plugin instead of deleting them. It adds their path to a file under (~/.grogra.de-plaftorm/blacklist). Blacklisted plugins are not loaded in groimp so a new version can be installed. (blacklist and disable are different: one is loaded but disabled the other is not loaded).
The list of available plugin is provided by the "repositories" that you can see under the plugin manager "repositories".
You can add your repositories that contains plugin metadata as (a JSON that contains the plugins data or a local directory in which some groimp plugin exist).
All of these actions are doable from groim commands. Thus, accessible from the api, cli, and in headless with the command parameter.


====== GroIMP commands ======

The plugin manager's operations are based on GroIMP commands. Thus, usable without using the GUI (neither the Plugin Manager nor GroIMP GUI are required).
The list of commands is :

Exporting the list of currently installed plugins. This create a file with the list of plugin and their version installed. - complete path: /pluginmanager/commands/file/exportPlugins.
Importing a list of plugins. The plugin manager will install a list of plugins provided by file containing the plugin id and version - complete path: /pluginmanager/commands/file/importPlugins.
Reload the plugin repositories. This refresh the list of available plugins - complete path: /pluginmanager/commands/data/reloadRepo.
Clear the cache. This delete all cached data of both plugin, and repositories - complete path: /pluginmanager/commands/data/clearCache.


===== Usage from commandline =====

it is possilbe to install plugins without opening GroIMP by using the following commands:
<code>
#install
java -jar core.jar --headless -- -cmd /pluginmanager/commands/installCMD=de.grogra.gltf;de.grogra.cli

#uninstall
java -jar core.jar --headless -- -cmd /pluginmanager/commands/uninstallCMD=de.grogra.gltf;de.grogra.cli

#disable
java -jar core.jar --headless -- -cmd /pluginmanager/commands/disableCMD=de.grogra.gltf;de.grogra.cli

</code>