Feature toggling is done at build time, with a check for toggleOnCustom in the gradle.properties file. The
build.gradle file in the db module has an extra task called enableCustom that only runs if toggleOnCustom is set
to true.
The actual implementation of toggling is mostly done by using the existing permissions framework. The UI shows and hides certain menu items and pages if the logged in user has the corresponding permission. Features are effectively toggled off by removing the applicable permission completely from the system. Since the permission does not exist, the user does not have the permission and is not able to interact with the applicable feature.
The settings and tabs in the Other Settings page are shown by getting all of the settings in the
configuration_settings table that have isConfigurable to true, grouped by groupName. So these settings and tabs
are toggled off by changing the custom settings isConfigurable column to false.
A final setting is toggled off by changing the default page setting back to the home page, and not the custom dashboard.
The build process removes the custom permissions, sets the custom settings to not configurable, and changes the default
page to the home page, in a file called disable_custom.sql. The enableCustom task re-adds these permissions, sets the
custom settings to configurable again, and changes the home page back to the dashboard page, in a file called
enable_custom.sql.
For minor changes in toggling UI items, new permissions should be created in the seed, toggled off in the
disable_custom.sql script, toggled back on in the enable_custom.sql script, and checked for in the HTML.
For more extensive changes, the toggling mechanism can be copied for how to toggle at build time.