Class reference

ResourceFormatLoader

Inherits RefCounted

Loads a specific resource type from a file.

Description

Redot loads resources in the editor or in exported games using ResourceFormatLoaders. They are queried automatically via the ResourceLoader singleton, or when a resource with internal dependencies is loaded. Each file type may load as a different resource type, so multiple ResourceFormatLoaders are registered in the engine. Extending this class allows you to define your own loader. Be sure to respect the documented return types and values. You should give it a global class name with class_name for it to be registered. Like built-in ResourceFormatLoaders, it will be called automatically when loading resources of its handled type(s). You may also implement a ResourceFormatSaver. Note: You can also extend EditorImportPlugin if the resource type you need exists but Redot is unable to load its format. Choosing one way over another depends on if the format is suitable or not for the final exported game. For example, it's better to import .png textures as .ctex (CompressedTexture2D) first, so they can be loaded with better efficiency on the graphics card.

Methods

`bool _exists(String path) virtual const`

`PackedStringArray _get_classes_used(String path) virtual const`

`PackedStringArray _get_dependencies(String path, bool add_types) virtual const`

Should return the dependencies for the resource at the given path. Each dependency is a string composed of one to three sections separated by ::, with trailing empty sections omitted: - The first section should contain the UID if the resource has one. Otherwise, it should contain the file path. - The second section should contain the class name of the dependency if add_types is true. Otherwise, it should be empty. - The third section should contain the fallback path if the resource has a UID. Otherwise, it should be empty.

				func _get_dependencies(path, add_types):
					return [
						"uid://fqgvuwrkuixh::Script::res://script.gd",
						"uid://fqgvuwrkuixh::::res://script.gd",
						"res://script.gd::Script",
						"res://script.gd",
					]

Note: Custom resource types defined by scripts aren't known by the ClassDB, so "Resource" can be used for the class name.

`PackedStringArray _get_recognized_extensions() virtual const`

Gets the list of extensions for files this loader is able to read.

`String _get_resource_script_class(String path) virtual const`

Returns the script class name associated with the Resource under the given path. If the resource has no script or the script isn't a named class, it should return "".

`String _get_resource_type(String path) virtual const`

Gets the class name of the resource associated with the given path. If the loader cannot handle it, it should return "". Note: Custom resource types defined by scripts aren't known by the ClassDB, so you might just return "Resource" for them.

`int _get_resource_uid(String path) virtual const`

Should return the unique ID for the resource associated with the given path. If this method is not overridden, a .uid file is generated along with the resource file, containing the unique ID.

`bool _handles_type(StringName type) virtual const`

Tells which resource class this loader can load. Note: Custom resource types defined by scripts aren't known by the ClassDB, so you might just handle "Resource" for them.

`Variant _load(String path, String original_path, bool use_sub_threads, int cache_mode) virtual const`

Loads a resource when the engine finds this loader to be compatible. If the loaded resource is the result of an import, original_path will target the source file. Returns a Resource object on success, or an Error constant in case of failure. The cache_mode property defines whether and how the cache should be used or updated when loading the resource. See CacheMode for details.

`bool _recognize_path(String path, StringName type) virtual const`

Tells whether or not this loader should load a resource from its resource path for a given type. If it is not implemented, the default behavior returns whether the path's extension is within the ones provided by _get_recognized_extensions(), and if the type is within the ones provided by _get_resource_type().

`int _rename_dependencies(String path, Dictionary renames) virtual const`

If implemented, renames dependencies within the given resource and saves it. renames is a dictionary { String => String } mapping old dependency paths to new paths. Returns OK on success, or an Error constant in case of failure.

Constants

`CACHE_MODE_IGNORE = 0`

Enum: CacheMode

Neither the main resource (the one requested to be loaded) nor any of its subresources are retrieved from cache nor stored into it. Dependencies (external resources) are loaded with CACHE_MODE_REUSE.

`CACHE_MODE_REUSE = 1`

Enum: CacheMode

The main resource (the one requested to be loaded), its subresources, and its dependencies (external resources) are retrieved from cache if present, instead of loaded. Those not cached are loaded and then stored into the cache. The same rules are propagated recursively down the tree of dependencies (external resources).

`CACHE_MODE_REPLACE = 2`

Enum: CacheMode

Like CACHE_MODE_REUSE, but the cache is checked for the main resource (the one requested to be loaded) as well as for each of its subresources. Those already in the cache, as long as the loaded and cached types match, have their data refreshed from storage into the already existing instances. Otherwise, they are recreated as completely new objects.

`CACHE_MODE_IGNORE_DEEP = 3`

Enum: CacheMode

Like CACHE_MODE_IGNORE, but propagated recursively down the tree of dependencies (external resources).

`CACHE_MODE_REPLACE_DEEP = 4`

Enum: CacheMode

Like CACHE_MODE_REPLACE, but propagated recursively down the tree of dependencies (external resources).

Source revision 5592dc3a7a61