Remove the INSTALLED_APPS setting

The INSTALLED APPS setting is now replaced by the
new COMMON_EXTRA_APPS and COMMON_DISABLED_APPS.

Exposing the INSTALLED_APPS setting had the side effect
of blocking new apps that were added in new versions.

Signed-off-by: Roberto Rosario <roberto.rosario@mayan-edms.com>

HISTORY.rst

@@ -18,6 +18,8 @@
   existing tags.
 * Add proper redirection after moving a document to the
   trash.
+* Remove the INSTALLED_APPS setting. Replace it with
+  the new COMMON_EXTRA_APPS and COMMON_DISABLED_APPS.
 
 3.2.3 (2019-06-21)
 ==================

docs/releases/3.2.4.rst

@@ -26,6 +26,8 @@ Changes
   existing tags.
 - Add proper redirection after moving a document to the
   trash.
+- Remove the INSTALLED_APPS setting. Replace it with
+  the new COMMON_EXTRA_APPS and COMMON_DISABLED_APPS.
 
 Removals
 --------

mayan/apps/common/settings.py

@@ -26,6 +26,26 @@ settings_db_sync_task_delay = namespace.add_setting(
         'propagate.'
     )
 )
+setting_disabled_apps = namespace.add_setting(
+    global_name='COMMON_DISABLED_APPS',
+    default=settings.COMMON_DISABLED_APPS,
+    help_text=_(
+        'A list of strings designating all applications that are to be removed '
+        'from the list normally installed by Mayan EDMS. Each string should be '
+        'a dotted Python path to: an application configuration class (preferred), '
+        'or a package containing an application.'
+    ),
+)
+setting_extra_apps = namespace.add_setting(
+    global_name='COMMON_EXTRA_APPS',
+    default=settings.COMMON_EXTRA_APPS,
+    help_text=_(
+        'A list of strings designating all applications that are installed '
+        'beyond those normally installed by Mayan EDMS. Each string should be '
+        'a dotted Python path to: an application configuration class (preferred), '
+        'or a package containing an application.'
+    ),
+)
 setting_home_view = namespace.add_setting(
     global_name='COMMON_HOME_VIEW',
     default=DEFAULT_COMMON_HOME_VIEW, help_text=_(
@@ -254,16 +274,6 @@ setting_django_file_upload_max_memory_size = namespace.add_setting(
         'DATA_UPLOAD_MAX_MEMORY_SIZE.'
     ),
 )
-setting_django_installed_apps = namespace.add_setting(
-    global_name='INSTALLED_APPS',
-    default=settings.INSTALLED_APPS,
-    help_text=_(
-        'A list of strings designating all applications that are enabled '
-        'in this Django installation. Each string should be a dotted '
-        'Python path to: an application configuration class (preferred), '
-        'or a package containing an application.'
-    ),
-)
 setting_django_login_url = namespace.add_setting(
     global_name='LOGIN_URL',
     default=settings.LOGIN_URL,

mayan/settings/base.py

@@ -360,6 +360,8 @@ else:
 
 
 BASE_INSTALLED_APPS = INSTALLED_APPS
+COMMON_EXTRA_APPS = ()
+COMMON_DISABLED_APPS = ()
 
 CONFIGURATION_FILEPATH = os.path.join(MEDIA_ROOT, CONFIGURATION_FILENAME)
 CONFIGURATION_LAST_GOOD_FILEPATH = os.path.join(
@@ -378,3 +380,12 @@ for app in INSTALLED_APPS:
             'Update the app references in the file config.yml as detailed '
             'in https://docs.mayan-edms.com/releases/3.2.html#backward-incompatible-changes'
         )
+
+
+for APP in COMMON_EXTRA_APPS:
+    INSTALLED_APPS = INSTALLED_APPS + (APP,)
+
+
+INSTALLED_APPS = [
+    APP for APP in INSTALLED_APPS if APP not in COMMON_DISABLED_APPS
+]