Creating Your First Extension¶
Plugins consist of two things. First, a meta-data file describing the extension which includes things like a name, the author, and where to find the extension. Second, the code which can take the form of a shared library or python module.
Builder supports writing extensions in C, Vala, or Python. We will be using Python for our examples in this tutorial because it is both succinct and easy to get started with.
First, we will look at our extension meta-data file. The file should have the file-suffix of ”.plugin” and it’s format is familiar. It starts with a line containing “[Plugin]” indicating this is extension metadata. Then it is followed by a series of “Key=Value” key-pairs.
We often use the words “extension” and “plugin” interchangeably.
# my_plugin.plugin [Plugin] Name=My Plugin Loader=python3 Module=my_plugin Author=Angela Avery
Now we can create a simple plugin that will print “hello” when Builder starts and “goodbye” when Builder exits.
# my_plugin.py import gi from gi.repository import GObject from gi.repository import Ide class MyAppAddin(GObject.Object, Ide.ApplicationAddin): def do_load(self, application): print("hello") def do_unload(self, application): print("goodbye")
In the python file above, we define a new extension called
It inherits from
GObject.Object (which is our base object) and implements the interface
We wont get too much into objects and interfaces here, but the plugin manager uses this information to determine when and how to load our extension.
Ide.ApplicationAddin requires that two methods are implemented.
The first is called
do_load and is executed when the extension should load.
And the second is called
do_unload and is executed when the plugin should cleanup after itself.
Each of the two functions take a parameter called
application which is an
Loading our Extension¶
Now place the two files in
If we run Builder from the command line, we should see the output from our plugin!
[angela@localhost ~] gnome-builder hello
Now if we close the window, we should see that our plugin was unloaded.
[angela@localhost ~] gnome-builder hello goodbye
Sometimes plugins need to embed resources. Builder will automatically
load a file that matches the name
$module_name.gresource if it
placed alongside the
If you are writing an extension in C or Vala, simply embed GResources as normal.
<?xml version="1.0" encoding="UTF-8"?> <gresources> <gresource prefix="/org/gnome/builder/plugins/my-plugin"> <file preprocess="xml-stripblanks" compressed="true">gtk/menus.ui</file> </gresource> </gresources>
Next, compile the resources using
glib-compile-resources --generate my-plugin.gresource my-plugin.gresource.xml
Now you should have a file named
my-plugin.gresource in the current directory.
Ship this file along with your
my-plugin.plugin and Python module.
Next, continue on to learn about other interfaces you can implement in Builder to extend it’s features!