i18n: Expose editor's translation via EditorInterface.

[zaevi]

Closes godotengine/godot-proposals#6885
Closes godotengine/godot-proposals#1262

Expose editor's translation via EditorInterface.get_editor_translation(). This will allow developers to add translations for their plugin.

Example (Updated):

var translation : Translation
var tool_translation := EditorInterface.get_editor_translation()

func load_translation():
    if not tool_translation:
        return
    var tr_path = "res://addons/tr_test/locales/" + tool_translation.locale + ".po"
    if ResourceLoader.exists(tr_path):
        translation = load(tr_path) 
        for msg in translation.get_message_list():
            if tool_translation.get_message(msg) != "":
                push_warning("Translation conflict for '%s'! Please report to the author!" % msg)
                translation.erase_message(msg) # avoid removal on unloading
            else:
                tool_translation.add_message(msg, translation.get_message(msg))

func unload_translation():
    if translation:
        for msg in translation.get_message_list():
            tool_translation.erase_message(msg)
        translation = null

tr_test.zip

[KoBeWi]

Related: #77104

[timothyqiu]

One thing I think #77104 does better is that it keeps track of what messages are actually added. This makes it easy to perform inverse operations.

Exposing Translation directly would require the caller to consider possible collisions. In order to safely add plugin translation, they will need to exclude & record existing messages themselves when the plugin is enabled. When disabling the plugin, they will need to remove the ones that don't exist in the original translation based on the previous record. It's tedious and I don't think most people would comply.

[zaevi]

I think plugin developers should handle conflicts and removals themselves. They will find and resolve translation conflicts when debugging their plugins.

For removal, it's also easy. Continuing with the example above:

func unload_translation():
	if translation:
		for msg in translation.get_message_list():
			tool_translation.erase_message(msg)
		translation = null

[timothyqiu]

I think plugin developers should handle conflicts and removals themselves.

Editor translation changes. Entries from other plugins would also collide with your plugin.

[zaevi]

Editor translation changes. Entries from other plugins would also collide with your plugin.

This can also be handled manually:

        # ...
        for msg in translation.get_message_list():
            if tool_translation.get_message(msg) != "":
                push_warning("Translation conflict for '%s'! Please report to the author!" % msg)
                translation.erase_message(msg) # avoid removal on unloading
            else:
                tool_translation.add_message(msg, translation.get_message(msg))

I think we can document it to guide developers on how to support i18n for their plugins.

[akien-mga]

Superseded by #95787.