Expose scene unique id functionality in Resource

3 files changed, 28 insertions, 1 deletions

diff --git a/core/io/resource.cpp b/core/io/resource.cpp
index 7e8d0b43cd..6d32035d25 100644
--- a/core/io/resource.cpp
+++ b/core/io/resource.cpp
@@ -130,6 +130,16 @@ String Resource::generate_scene_unique_id() {
 }
 
 void Resource::set_scene_unique_id(const String &p_id) {
+	bool is_valid = true;
+	for (int i = 0; i < p_id.length(); i++) {
+		if (!is_ascii_identifier_char(p_id[i])) {
+			is_valid = false;
+			scene_unique_id = Resource::generate_scene_unique_id();
+			break;
+		}
+	}
+
+	ERR_FAIL_COND_MSG(!is_valid, "The scene unique ID must contain only letters, numbers, and underscores.");
 	scene_unique_id = p_id;
 }
 
@@ -532,6 +542,10 @@ void Resource::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("get_local_scene"), &Resource::get_local_scene);
 	ClassDB::bind_method(D_METHOD("setup_local_to_scene"), &Resource::setup_local_to_scene);
 
+	ClassDB::bind_static_method("Resource", D_METHOD("generate_scene_unique_id"), &Resource::generate_scene_unique_id);
+	ClassDB::bind_method(D_METHOD("set_scene_unique_id", "id"), &Resource::set_scene_unique_id);
+	ClassDB::bind_method(D_METHOD("get_scene_unique_id"), &Resource::get_scene_unique_id);
+
 	ClassDB::bind_method(D_METHOD("emit_changed"), &Resource::emit_changed);
 
 	ClassDB::bind_method(D_METHOD("duplicate", "subresources"), &Resource::duplicate, DEFVAL(false));
@@ -542,6 +556,7 @@ void Resource::_bind_methods() {
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "resource_local_to_scene"), "set_local_to_scene", "is_local_to_scene");
 	ADD_PROPERTY(PropertyInfo(Variant::STRING, "resource_path", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_EDITOR), "set_path", "get_path");
 	ADD_PROPERTY(PropertyInfo(Variant::STRING, "resource_name"), "set_name", "get_name");
+	ADD_PROPERTY(PropertyInfo(Variant::STRING, "resource_scene_unique_id", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NONE), "set_scene_unique_id", "get_scene_unique_id");
 
 	MethodInfo get_rid_bind("_get_rid");
 	get_rid_bind.return_val.type = Variant::RID;
diff --git a/doc/classes/Resource.xml b/doc/classes/Resource.xml
index 85372288e7..cec936ac3e 100644
--- a/doc/classes/Resource.xml
+++ b/doc/classes/Resource.xml
@@ -59,6 +59,12 @@
 				[/codeblock]
 			</description>
 		</method>
+		<method name="generate_scene_unique_id" qualifiers="static">
+			<return type="String" />
+			<description>
+				Generates a unique identifier for a resource to be contained inside a [PackedScene], based on the current date, time, and a random value. The returned string is only composed of letters ([code]a[/code] to [code]y[/code]) and numbers ([code]0[/code] to [code]8[/code]). See also [member resource_scene_unique_id].
+			</description>
+		</method>
 		<method name="get_local_scene" qualifiers="const">
 			<return type="Node" />
 			<description>
@@ -98,6 +104,12 @@
 			The unique path to this resource. If it has been saved to disk, the value will be its filepath. If the resource is exclusively contained within a scene, the value will be the [PackedScene]'s filepath, followed by a unique identifier.
 			[b]Note:[/b] Setting this property manually may fail if a resource with the same path has already been previously loaded. If necessary, use [method take_over_path].
 		</member>
+		<member name="resource_scene_unique_id" type="String" setter="set_scene_unique_id" getter="get_scene_unique_id">
+			An unique identifier relative to the this resource's scene. If left empty, the ID is automatically generated when this resource is saved inside a [PackedScene]. If the resource is not inside a scene, this property is empty by default.
+			[b]Note:[/b] When the [PackedScene] is saved, if multiple resources in the same scene use the same ID, only the earliest resource in the scene hierarchy keeps the original ID. The other resources are assigned new IDs from [method generate_scene_unique_id].
+			[b]Note:[/b] Setting this property does not emit the [signal changed] signal.
+			[b]Warning:[/b] When setting, the ID must only consist of letters, numbers, and underscores. Otherwise, it will fail and default to a randomly generated ID.
+		</member>
 	</members>
 	<signals>
 		<signal name="changed">
diff --git a/editor/doc_tools.cpp b/editor/doc_tools.cpp
index ee3e54e9df..52b0d485cf 100644
--- a/editor/doc_tools.cpp
+++ b/editor/doc_tools.cpp
@@ -477,7 +477,7 @@ void DocTools::generate(BitField<GenerateFlags> p_flags) {
 				}
 
 				if (properties_from_instance) {
-					if (E.name == "resource_local_to_scene" || E.name == "resource_name" || E.name == "resource_path" || E.name == "script") {
+					if (E.name == "resource_local_to_scene" || E.name == "resource_name" || E.name == "resource_path" || E.name == "script" || E.name == "resource_scene_unique_id") {
 						// Don't include spurious properties from Object property list.
 						continue;
 					}