How can I install a Gsettings Schema without root privileges?

The typical workflow to install a Gsettings Schema is this:

1. Create a schema, with the extension .gschema.xml, with contents like this:

   <?xml version="1.0" encoding="UTF-8"?>
   <schemalist>
     <schema id="com.companyname.appname" path="/com/companyname/appname/">
         <key type="b" name="mybool">
             <default>false</default>
             <summary>Example summary</summary>
             <description>Example description</description>
         </key>
     </schema>
   </schemalist>
   

2. Copy the schema to /usr/share/glib-2.0/schemas/.

3. Compile the schema by running this command:

   sudo glib-compile-schemas /usr/share/glib-2.0/schemas/
   

However, writing to /usr/share/glib-2.0/schemas/ requires root privileges. Is there a way to install a schema to a non-global user directory?

Solution 1:

You can copy and compile your Gsettings Schemas to a user-writable directory:

$ cp com.companyname.appname ~/schemas/
$ glib-compile-schemas ~/schemas/

The tricky bit is to configure the application to use that particular directory. There are two ways to do this:

• With the GSETTINGS_SCHEMA_DIR environment variable:

  $ GSETTINGS_SCHEMA_DIR=~/schemas/ ./example.py
  

• Or using GSettingsSchemaSource and GSettingSchema objects:

  If you have access to the source code of your program, you can modify it to load compiled schemas from any directory. Here's how would do it in Python, although you could do this in any programming language with GObject introspection:

  schema_source = Gio.SettingsSchemaSource.new_from_directory(
      os.path.expanduser("~/schemas"),
      Gio.SettingsSchemaSource.get_default(),
      False,
  )
  schema = schema_source.lookup('com.companyname.appname', False)
  settings = Gio.Settings.new_full(schema, None, None)
  settings.set_boolean('mybool', True)
  

References:

• C API documentation for GSettingsSchema and GSettingsSchemaSource
• Introductory blog post about GSettings in Python