feat: ✨ Mod Hooks

addons/mod_loader/_export_plugin/export_plugin.gd

@@ -0,0 +1,28 @@
+extends EditorExportPlugin
+
+const ModHookPreprocessorScript := preload("res://addons/mod_loader/internal/mod_hook_preprocessor.gd")
+static var ModHookPreprocessor
+
+
+func _get_name() -> String:
+	return "Godot Mod Loader Export Plugin"
+
+
+func _export_begin(features: PackedStringArray, is_debug: bool, path: String, flags: int) -> void:
+	ModHookPreprocessor = ModHookPreprocessorScript.new()
+	ModHookPreprocessor.process_begin()
+
+
+func _export_file(path: String, type: String, features: PackedStringArray) -> void:
+	if path.begins_with("res://addons") or path.begins_with("res://mods-unpacked"):
+		return
+
+	if type != "GDScript":
+		return
+
+	skip()
+	add_file(
+		path,
+		ModHookPreprocessor.process_script(path).to_utf8_buffer(),
+		false
+	)

addons/mod_loader/_export_plugin/plugin.cfg

@@ -0,0 +1,7 @@
+[plugin]
+
+name="A Mod Loader Export"
+description="Export plugin to generate the necessary callable stack."
+author="KANA"
+version="0.1"
+script="plugin.gd"

addons/mod_loader/_export_plugin/plugin.gd

@@ -0,0 +1,14 @@
+@tool
+extends EditorPlugin
+
+
+var _export_plugin: EditorExportPlugin
+
+
+func _enter_tree():
+	_export_plugin = preload("res://addons/mod_loader/_export_plugin/export_plugin.gd").new()
+	add_export_plugin(_export_plugin)
+
+
+func _exit_tree() -> void:
+	remove_export_plugin(_export_plugin)

addons/mod_loader/api/mod.gd

@@ -11,6 +11,32 @@ extends Object
 const LOG_NAME := "ModLoader:Mod"
 
 
+static func set_modding_hooks(new_callable_stack: Dictionary) -> void:
+	ModLoaderStore.modding_hooks = new_callable_stack
+
+
+static func add_hook(mod_callable: Callable, script_path: String, method_name: String, is_before := false) -> void:
+	ModLoaderStore.any_mod_hooked = true
+	var hash = get_hook_hash(script_path,method_name,is_before)
+	if not ModLoaderStore.modding_hooks.has(hash):
+		ModLoaderStore.modding_hooks[hash] = []
+	ModLoaderStore.modding_hooks[hash].push_back(mod_callable)
+	ModLoaderLog.debug("Added hook script: \"%s\" method: \"%s\" is_before: \"%s\"" % [script_path, method_name, is_before], LOG_NAME)
+	if not ModLoaderStore.hooked_script_paths.has(script_path):
+		ModLoaderStore.hooked_script_paths[script_path] = null
+
+
+static func call_hooks(self_object: Object, args: Array, hook_hash:int) -> void:
+	var hooks = ModLoaderStore.modding_hooks.get(hook_hash, null)
+	if hooks:
+		for mod_func in hooks:
+			mod_func.call(self_object, args)
+
+
+static func get_hook_hash(path:String, method:String, is_before:bool) -> int:
+	return hash(path + method + ("before" if is_before else "after"))
+
+
 ## Installs a script extension that extends a vanilla script.[br]
 ## The [code]child_script_path[/code] should point to your mod's extender script.[br]
 ## Example: [code]"MOD/extensions/singletons/utils.gd"[/code][br]

addons/mod_loader/internal/cache.gd

@@ -31,7 +31,7 @@ static func add_data(key: String, data: Dictionary) -> Dictionary:
 # Get data from a specific key
 static func get_data(key: String) -> Dictionary:
 	if not ModLoaderStore.cache.has(key):
-		ModLoaderLog.error("key: \"%s\" not found in \"ModLoaderStore.cache\"" % key, LOG_NAME)
+		ModLoaderLog.info("key: \"%s\" not found in \"ModLoaderStore.cache\"" % key, LOG_NAME)
 		return {}
 
 	return ModLoaderStore.cache[key]

addons/mod_loader/internal/file.gd

@@ -227,4 +227,3 @@ static func dir_exists(path: String) -> bool:
 # modders in understanding and troubleshooting issues.
 static func _code_note(_msg:String):
 	pass
-

addons/mod_loader/internal/mod_hook_packer.gd

@@ -0,0 +1,65 @@
+class_name _ModLoaderModHookPacker
+extends RefCounted
+
+
+# This class is used to generate mod hooks on demand and pack them into a zip file.
+# Currently all of the included functions are internal and should only be used by the mod loader itself.
+
+const LOG_NAME := "ModLoader:ModHookPacker"
+
+
+static func start() -> void:
+	var hook_pre_processor = _ModLoaderModHookPreProcessor.new()
+	hook_pre_processor.process_begin()
+
+	var mod_hook_pack_path := _ModLoaderPath.get_path_to_hook_pack()
+
+	# Create mod hook pack path if necessary
+	if not DirAccess.dir_exists_absolute(mod_hook_pack_path.get_base_dir()):
+		var error := DirAccess.make_dir_recursive_absolute(mod_hook_pack_path.get_base_dir())
+		if not error == OK:
+			ModLoaderLog.error("Error creating the mod hook directory at %s" % mod_hook_pack_path, LOG_NAME)
+			return
+		ModLoaderLog.debug("Created dir at: %s" % mod_hook_pack_path, LOG_NAME)
+
+	# Create mod hook zip
+	var zip_writer := ZIPPacker.new()
+	var error: Error
+
+	if not FileAccess.file_exists(mod_hook_pack_path):
+		# Clear cache if the hook pack does not exist
+		_ModLoaderCache.remove_data("hooks")
+		error = zip_writer.open(mod_hook_pack_path)
+	else:
+		# If there is a pack already append to it
+		error = zip_writer.open(mod_hook_pack_path, ZIPPacker.APPEND_ADDINZIP)
+	if not error == OK:
+		ModLoaderLog.error("Error(%s) writing to zip file at path: %s" % [error, mod_hook_pack_path], LOG_NAME)
+		return
+
+	var cache := _ModLoaderCache.get_data("hooks")
+	var script_paths_with_hook: Array = [] if cache.is_empty() else cache.script_paths
+	var new_hooks_created := false
+
+	# Get all scripts that need processing
+	ModLoaderLog.debug("Scripts requiring hooks: %s" % [ModLoaderStore.hooked_script_paths.keys()], LOG_NAME)
+	for path in ModLoaderStore.hooked_script_paths.keys():
+		if path in script_paths_with_hook:
+			continue
+
+		var processed_source_code := hook_pre_processor.process_script(path)
+
+		zip_writer.start_file(path.trim_prefix("res://"))
+		zip_writer.write_file(processed_source_code.to_utf8_buffer())
+		zip_writer.close_file()
+
+		ModLoaderLog.debug("Hooks created for script: %s" % path, LOG_NAME)
+		new_hooks_created = true
+		script_paths_with_hook.push_back(path)
+
+	if new_hooks_created:
+		_ModLoaderCache.update_data("hooks", {"script_paths": script_paths_with_hook})
+		_ModLoaderCache.save_to_file()
+		ModLoader.new_hooks_created.emit()
+
+	zip_writer.close()