BlockScriptSerialization: Re-generate block definition for object property blocks

The drag & drop object property's blocks disappear after save & re-open
the Godot project. And, shows error:

core/variant/variant_utility.cpp:1092 - Cannot construct block from null block definition.
res://addons/block_code/ui/block_canvas/block_canvas.gd:348 - Invalid call. Nonexistent function 'set_parameter_values_on_ready' in base 'Nil'.

It is because the object property blocks are not the predefined blocks
in the catalog. So, Block Coding plugin cannot find the block definition
from the catalog when places the object property blocks into the cavas
via _block_to_ast_node() after re-open the project.

Therefore, introduce _get_obj_property_block_definition() generating
object property's getter/setter block definition for
get_block_definition(). Besides, it also needs the object property's
value type. So, pass the AST node's arguments which is a Dictionary and
may contain the "value" feild into get_block_definition(), too.

https://phabricator.endlessm.com/T35649

Author: starnight

addons/block_code/serialization/block_script_serialization.gd

@@ -70,7 +70,7 @@ 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)
@@ -79,24 +79,29 @@ 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])
 
-	var block_definition = _get_base_block_definition(block_name)
+	block_definition = _get_base_block_definition(block_name)
+	if block_definition != null:
+		return block_definition
 
-	if block_definition == null:
-		# 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
-		#        are generated on demand for any block name containing a ":".
-		#        Please remove this fallback when it is no longer necessary.
-		split = block_name.rsplit("_", true, 1)
-		return _get_parameter_block_definition(split[0], split[1])
+	var property_value = arguments.get("value", null)
+	block_definition = _get_obj_property_block_definition(block_name, property_value)
+	if block_definition != null:
+		return block_definition
 
-	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
+	#        are generated on demand for any block name containing a ":".
+	#        Please remove this fallback when it is no longer necessary.
+	split = block_name.rsplit("_", true, 1)
+	return _get_parameter_block_definition(split[0], split[1])
 
 
 func _get_base_block_definition(block_name: String) -> BlockDefinition:
@@ -133,6 +138,33 @@ func _get_parameter_block_definition(block_name: String, parameter_name: String)
 	return block_definition
 
 
+func _get_obj_property_block_definition(block_name: String, property_value: Variant) -> BlockDefinition:
+	var block_definition: BlockDefinition
+	var variable: VariableDefinition
+	var property_name: String
+	var is_getter = true
+
+	if block_name.find("get_var_") == 0:
+		property_name = block_name.get_slice("get_var_", 1)
+	elif block_name.find("set_var_") == 0:
+		property_name = block_name.get_slice("set_var_", 1)
+		is_getter = false
+	else:
+		return null
+
+	if is_getter:
+		# Getter block needs the property name and variant type information by
+		# decoding block name
+		var split := property_name.rsplit("_", true, 1)
+		variable = VariableDefinition.new(split[0], int(split[1]))
+		block_definition = BlocksCatalog.get_property_getter_block_definition(variable)
+	else:
+		variable = VariableDefinition.new(property_name, typeof(property_value))
+		block_definition = BlocksCatalog.get_property_setter_block_definition(variable)
+
+	return block_definition
+
+
 func _update_block_definitions():
 	_available_blocks.clear()
 	_available_blocks.append_array(_get_inherited_block_definitions())
@@ -202,14 +234,15 @@ 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))
@@ -220,14 +253,15 @@ 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, value_node.arguments)
+
 	return ast_value_node