BlockScriptSerialization: Re-generate block definition for resource file blocks

Drag & drop resouce files as blocks into canvas has been implemented.
This commit focuses on serializing from the resource file blocks to AST
nodes and values.

The resource file's path is saved as in the arguments "file_path" feild.
So, pass the arguments, which may have "file_path" into
get_block_definition() to rebuild resource file's block definition.

https://phabricator.endlessm.com/T35712

Author: starnight

addons/block_code/serialization/block_script_serialization.gd

@@ -72,7 +72,7 @@ func instantiate_block(block_definition: BlockDefinition) -> Block:
 
 
 func instantiate_block_by_name(block_name: String) -> Block:
-	var block_definition := get_block_definition(block_name)
+	var block_definition := get_block_definition(block_name, {})
 
 	if block_definition == null:
 		push_warning("Cannot find a block definition for %s" % block_name)
@@ -81,12 +81,14 @@ func instantiate_block_by_name(block_name: String) -> Block:
 	return instantiate_block(block_definition)
 
 
-func get_block_definition(block_name: String) -> BlockDefinition:
+func get_block_definition(block_name: String, arguments: Dictionary) -> BlockDefinition:
 	var split := block_name.split(":", true, 1)
 	var block_definition: BlockDefinition
 
 	if len(split) > 1:
-		return _get_parameter_block_definition(split[0], split[1])
+		block_definition = _get_parameter_block_definition(split[0], split[1])
+		if block_definition:
+			return block_definition
 
 	block_definition = _get_base_block_definition(block_name)
 	if block_definition != null:
@@ -96,6 +98,11 @@ func get_block_definition(block_name: String) -> BlockDefinition:
 	if block_definition != null:
 		return block_definition
 
+	var file_path = arguments.get("file_path", "")
+	block_definition = _get_resource_block_definition(block_name, file_path)
+	if block_definition != null:
+		return block_definition
+
 	# FIXME: This is a workaround for old-style output block references.
 	#        These were generated ahead of time using a block name that has
 	#        a "_" before the parameter name. Now, these parameter blocks
@@ -182,6 +189,16 @@ func _get_parent_node_property_info(property_name: String) -> Dictionary:
 	return {}
 
 
+func _get_resource_block_definition(block_name: String, file_path: String) -> BlockDefinition:
+	if block_name != "get_resource_file_path":
+		return null
+
+	if file_path.is_empty() or not FileAccess.file_exists(file_path) or not ResourceLoader.exists(file_path):
+		return null
+
+	return BlocksCatalog.get_resource_block_definition(file_path)
+
+
 func _update_block_definitions():
 	_available_blocks.clear()
 	_available_blocks.append_array(_get_inherited_block_definitions())
@@ -251,14 +268,15 @@ func _tree_to_ast(tree: BlockSerializationTree) -> BlockAST:
 
 func _block_to_ast_node(node: BlockSerialization) -> BlockAST.ASTNode:
 	var ast_node := BlockAST.ASTNode.new()
-	ast_node.data = get_block_definition(node.name)
 
 	for arg_name in node.arguments:
 		var argument = node.arguments[arg_name]
 		if argument is ValueBlockSerialization:
 			argument = _value_to_ast_value(argument)
 		ast_node.arguments[arg_name] = argument
 
+	ast_node.data = get_block_definition(node.name, ast_node.arguments)
+
 	var children: Array[BlockAST.ASTNode]
 	for c in node.children:
 		children.append(_block_to_ast_node(c))
@@ -269,14 +287,15 @@ func _block_to_ast_node(node: BlockSerialization) -> BlockAST.ASTNode:
 
 func _value_to_ast_value(value_node: ValueBlockSerialization) -> BlockAST.ASTValueNode:
 	var ast_value_node := BlockAST.ASTValueNode.new()
-	ast_value_node.data = get_block_definition(value_node.name)
 
 	for arg_name in value_node.arguments:
 		var argument = value_node.arguments[arg_name]
 		if argument is ValueBlockSerialization:
 			argument = _value_to_ast_value(argument)
 		ast_value_node.arguments[arg_name] = argument
 
+	ast_value_node.data = get_block_definition(value_node.name, ast_value_node.arguments)
+
 	return ast_value_node