Fix Addon requires editor restart to become functional

4 files changed, 91 insertions, 20 deletions

diff --git a/core/io/resource_importer.cpp b/core/io/resource_importer.cpp
index b4c43abe00..a572dd562e 100644
--- a/core/io/resource_importer.cpp
+++ b/core/io/resource_importer.cpp
@@ -35,6 +35,8 @@
 #include "core/os/os.h"
 #include "core/variant/variant_parser.h"
 
+ResourceFormatImporterLoadOnStartup ResourceImporter::load_on_startup = nullptr;
+
 bool ResourceFormatImporter::SortImporterByName::operator()(const Ref<ResourceImporter> &p_a, const Ref<ResourceImporter> &p_b) const {
 	return p_a->get_importer_name() < p_b->get_importer_name();
 }
@@ -137,6 +139,20 @@ Error ResourceFormatImporter::_get_path_and_type(const String &p_path, PathAndTy
 }
 
 Ref<Resource> ResourceFormatImporter::load(const String &p_path, const String &p_original_path, Error *r_error, bool p_use_sub_threads, float *r_progress, CacheMode p_cache_mode) {
+#ifdef TOOLS_ENABLED
+	// When loading a resource on startup, we use the load_on_startup callback,
+	// which executes the loading in the EditorFileSystem. It can reimport
+	// the resource and retry the load, allowing the resource to be loaded
+	// even if it is not yet imported.
+	if (ResourceImporter::load_on_startup != nullptr) {
+		return ResourceImporter::load_on_startup(this, p_path, r_error, p_use_sub_threads, r_progress, p_cache_mode);
+	}
+#endif
+
+	return load_internal(p_path, r_error, p_use_sub_threads, r_progress, p_cache_mode, false);
+}
+
+Ref<Resource> ResourceFormatImporter::load_internal(const String &p_path, Error *r_error, bool p_use_sub_threads, float *r_progress, CacheMode p_cache_mode, bool p_silence_errors) {
 	PathAndType pat;
 	Error err = _get_path_and_type(p_path, pat);
 
@@ -148,6 +164,13 @@ Ref<Resource> ResourceFormatImporter::load(const String &p_path, const String &p
 		return Ref<Resource>();
 	}
 
+	if (p_silence_errors) {
+		// Note: Some importers do not create files in the .godot folder, so we need to check if the path is empty.
+		if (!pat.path.is_empty() && !FileAccess::exists(pat.path)) {
+			return Ref<Resource>();
+		}
+	}
+
 	Ref<Resource> res = ResourceLoader::_load(pat.path, p_path, pat.type, p_cache_mode, r_error, p_use_sub_threads, r_progress);
 
 #ifdef TOOLS_ENABLED
diff --git a/core/io/resource_importer.h b/core/io/resource_importer.h
index 7b1806c3d2..6ea5d0972a 100644
--- a/core/io/resource_importer.h
+++ b/core/io/resource_importer.h
@@ -35,6 +35,9 @@
 #include "core/io/resource_saver.h"
 
 class ResourceImporter;
+class ResourceFormatImporter;
+
+typedef Ref<Resource> (*ResourceFormatImporterLoadOnStartup)(ResourceFormatImporter *p_importer, const String &p_path, Error *r_error, bool p_use_sub_threads, float *r_progress, ResourceFormatLoader::CacheMode p_cache_mode);
 
 class ResourceFormatImporter : public ResourceFormatLoader {
 	struct PathAndType {
@@ -60,6 +63,7 @@ class ResourceFormatImporter : public ResourceFormatLoader {
 public:
 	static ResourceFormatImporter *get_singleton() { return singleton; }
 	virtual Ref<Resource> load(const String &p_path, const String &p_original_path = "", Error *r_error = nullptr, bool p_use_sub_threads = false, float *r_progress = nullptr, CacheMode p_cache_mode = CACHE_MODE_REUSE) override;
+	Ref<Resource> load_internal(const String &p_path, Error *r_error, bool p_use_sub_threads, float *r_progress, CacheMode p_cache_mode, bool p_silence_errors);
 	virtual void get_recognized_extensions(List<String> *p_extensions) const override;
 	virtual void get_recognized_extensions_for_type(const String &p_type, List<String> *p_extensions) const override;
 	virtual bool recognize_path(const String &p_path, const String &p_for_type = String()) const override;
@@ -94,6 +98,7 @@ public:
 
 	String get_import_base_path(const String &p_for_file) const;
 	Error get_resource_import_info(const String &p_path, StringName &r_type, ResourceUID::ID &r_uid, String &r_import_group_file) const;
+
 	ResourceFormatImporter();
 };
 
@@ -104,6 +109,8 @@ protected:
 	static void _bind_methods();
 
 public:
+	static ResourceFormatImporterLoadOnStartup load_on_startup;
+
 	virtual String get_importer_name() const = 0;
 	virtual String get_visible_name() const = 0;
 	virtual void get_recognized_extensions(List<String> *p_extensions) const = 0;
diff --git a/editor/editor_file_system.cpp b/editor/editor_file_system.cpp
index bcfc29f7a3..8cd130066e 100644
--- a/editor/editor_file_system.cpp
+++ b/editor/editor_file_system.cpp
@@ -33,8 +33,6 @@
 #include "core/config/project_settings.h"
 #include "core/extension/gdextension_manager.h"
 #include "core/io/file_access.h"
-#include "core/io/resource_importer.h"
-#include "core/io/resource_loader.h"
 #include "core/io/resource_saver.h"
 #include "core/object/worker_thread_pool.h"
 #include "core/os/os.h"
@@ -892,6 +890,7 @@ void EditorFileSystem::scan() {
 		// Set first_scan to false before the signals so the function doing_first_scan can return false
 		// in editor_node to start the export if needed.
 		first_scan = false;
+		ResourceImporter::load_on_startup = nullptr;
 		emit_signal(SNAME("filesystem_changed"));
 		emit_signal(SNAME("sources_changed"), sources_changed.size() > 0);
 	} else {
@@ -1502,6 +1501,7 @@ void EditorFileSystem::_notification(int p_what) {
 						// Set first_scan to false before the signals so the function doing_first_scan can return false
 						// in editor_node to start the export if needed.
 						first_scan = false;
+						ResourceImporter::load_on_startup = nullptr;
 						if (changed) {
 							emit_signal(SNAME("filesystem_changed"));
 						}
@@ -1524,6 +1524,7 @@ void EditorFileSystem::_notification(int p_what) {
 					// Set first_scan to false before the signals so the function doing_first_scan can return false
 					// in editor_node to start the export if needed.
 					first_scan = false;
+					ResourceImporter::load_on_startup = nullptr;
 					emit_signal(SNAME("filesystem_changed"));
 					emit_signal(SNAME("sources_changed"), sources_changed.size() > 0);
 				}
@@ -2401,14 +2402,16 @@ Error EditorFileSystem::_reimport_group(const String &p_group_file, const Vector
 	return err;
 }
 
-Error EditorFileSystem::_reimport_file(const String &p_file, const HashMap<StringName, Variant> &p_custom_options, const String &p_custom_importer, Variant *p_generator_parameters) {
+Error EditorFileSystem::_reimport_file(const String &p_file, const HashMap<StringName, Variant> &p_custom_options, const String &p_custom_importer, Variant *p_generator_parameters, bool p_update_file_system) {
 	print_verbose(vformat("EditorFileSystem: Importing file: %s", p_file));
 	uint64_t start_time = OS::get_singleton()->get_ticks_msec();
 
 	EditorFileSystemDirectory *fs = nullptr;
 	int cpos = -1;
-	bool found = _find_file(p_file, &fs, cpos);
-	ERR_FAIL_COND_V_MSG(!found, ERR_FILE_NOT_FOUND, "Can't find file '" + p_file + "'.");
+	if (p_update_file_system) {
+		bool found = _find_file(p_file, &fs, cpos);
+		ERR_FAIL_COND_V_MSG(!found, ERR_FILE_NOT_FOUND, "Can't find file '" + p_file + "'.");
+	}
 
 	//try to obtain existing params
 
@@ -2462,11 +2465,13 @@ Error EditorFileSystem::_reimport_file(const String &p_file, const HashMap<Strin
 
 	if (importer_name == "keep" || importer_name == "skip") {
 		//keep files, do nothing.
-		fs->files[cpos]->modified_time = FileAccess::get_modified_time(p_file);
-		fs->files[cpos]->import_modified_time = FileAccess::get_modified_time(p_file + ".import");
-		fs->files[cpos]->deps.clear();
-		fs->files[cpos]->type = "";
-		fs->files[cpos]->import_valid = false;
+		if (p_update_file_system) {
+			fs->files[cpos]->modified_time = FileAccess::get_modified_time(p_file);
+			fs->files[cpos]->import_modified_time = FileAccess::get_modified_time(p_file + ".import");
+			fs->files[cpos]->deps.clear();
+			fs->files[cpos]->type = "";
+			fs->files[cpos]->import_valid = false;
+		}
 		EditorResourcePreview::get_singleton()->check_for_invalidation(p_file);
 		return OK;
 	}
@@ -2626,16 +2631,18 @@ Error EditorFileSystem::_reimport_file(const String &p_file, const HashMap<Strin
 		}
 	}
 
-	// Update cpos, newly created files could've changed the index of the reimported p_file.
-	_find_file(p_file, &fs, cpos);
+	if (p_update_file_system) {
+		// Update cpos, newly created files could've changed the index of the reimported p_file.
+		_find_file(p_file, &fs, cpos);
 
-	// Update modified times, to avoid reimport.
-	fs->files[cpos]->modified_time = FileAccess::get_modified_time(p_file);
-	fs->files[cpos]->import_modified_time = FileAccess::get_modified_time(p_file + ".import");
-	fs->files[cpos]->deps = _get_dependencies(p_file);
-	fs->files[cpos]->type = importer->get_resource_type();
-	fs->files[cpos]->uid = uid;
-	fs->files[cpos]->import_valid = fs->files[cpos]->type == "TextFile" ? true : ResourceLoader::is_import_valid(p_file);
+		// Update modified times, to avoid reimport.
+		fs->files[cpos]->modified_time = FileAccess::get_modified_time(p_file);
+		fs->files[cpos]->import_modified_time = FileAccess::get_modified_time(p_file + ".import");
+		fs->files[cpos]->deps = _get_dependencies(p_file);
+		fs->files[cpos]->type = importer->get_resource_type();
+		fs->files[cpos]->uid = uid;
+		fs->files[cpos]->import_valid = fs->files[cpos]->type == "TextFile" ? true : ResourceLoader::is_import_valid(p_file);
+	}
 
 	if (ResourceUID::get_singleton()->has_id(uid)) {
 		ResourceUID::get_singleton()->set_id(uid, p_file);
@@ -2879,6 +2886,33 @@ Error EditorFileSystem::_resource_import(const String &p_path) {
 	return OK;
 }
 
+Ref<Resource> EditorFileSystem::_load_resource_on_startup(ResourceFormatImporter *p_importer, const String &p_path, Error *r_error, bool p_use_sub_threads, float *r_progress, ResourceFormatLoader::CacheMode p_cache_mode) {
+	ERR_FAIL_NULL_V(p_importer, Ref<Resource>());
+
+	if (!FileAccess::exists(p_path)) {
+		ERR_FAIL_V_MSG(Ref<Resource>(), vformat("Failed loading resource: %s. The file doesn't seem to exist.", p_path));
+	}
+
+	Ref<Resource> res;
+	bool can_retry = true;
+	bool retry = true;
+	while (retry) {
+		retry = false;
+
+		res = p_importer->load_internal(p_path, r_error, p_use_sub_threads, r_progress, p_cache_mode, can_retry);
+
+		if (res.is_null() && can_retry) {
+			can_retry = false;
+			Error err = singleton->_reimport_file(p_path, HashMap<StringName, Variant>(), "", nullptr, false);
+			if (err == OK) {
+				retry = true;
+			}
+		}
+	}
+
+	return res;
+}
+
 bool EditorFileSystem::_should_skip_directory(const String &p_path) {
 	String project_data_path = ProjectSettings::get_singleton()->get_project_data_path();
 	if (p_path == project_data_path || p_path.begins_with(project_data_path + "/")) {
@@ -3126,6 +3160,10 @@ EditorFileSystem::EditorFileSystem() {
 
 	scan_total = 0;
 	ResourceSaver::set_get_resource_id_for_path(_resource_saver_get_resource_id_for_path);
+
+	// Set the callback method that the ResourceFormatImporter will use
+	// if resources are loaded during the first scan.
+	ResourceImporter::load_on_startup = _load_resource_on_startup;
 }
 
 EditorFileSystem::~EditorFileSystem() {
diff --git a/editor/editor_file_system.h b/editor/editor_file_system.h
index 1bc24416eb..e1e0d83bfb 100644
--- a/editor/editor_file_system.h
+++ b/editor/editor_file_system.h
@@ -32,6 +32,8 @@
 #define EDITOR_FILE_SYSTEM_H
 
 #include "core/io/dir_access.h"
+#include "core/io/resource_importer.h"
+#include "core/io/resource_loader.h"
 #include "core/os/thread.h"
 #include "core/os/thread_safe.h"
 #include "core/templates/hash_set.h"
@@ -252,7 +254,7 @@ class EditorFileSystem : public Node {
 
 	void _update_extensions();
 
-	Error _reimport_file(const String &p_file, const HashMap<StringName, Variant> &p_custom_options = HashMap<StringName, Variant>(), const String &p_custom_importer = String(), Variant *generator_parameters = nullptr);
+	Error _reimport_file(const String &p_file, const HashMap<StringName, Variant> &p_custom_options = HashMap<StringName, Variant>(), const String &p_custom_importer = String(), Variant *generator_parameters = nullptr, bool p_update_file_system = true);
 	Error _reimport_group(const String &p_group_file, const Vector<String> &p_files);
 
 	bool _test_for_reimport(const String &p_path, bool p_only_imported_files);
@@ -296,6 +298,7 @@ class EditorFileSystem : public Node {
 	String _get_global_script_class(const String &p_type, const String &p_path, String *r_extends, String *r_icon_path) const;
 
 	static Error _resource_import(const String &p_path);
+	static Ref<Resource> _load_resource_on_startup(ResourceFormatImporter *p_importer, const String &p_path, Error *r_error, bool p_use_sub_threads, float *r_progress, ResourceFormatLoader::CacheMode p_cache_mode);
 
 	bool using_fat32_or_exfat; // Workaround for projects in FAT32 or exFAT filesystem (pendrives, most of the time)