path: root/doc/classes/Object.xml

<?xml version="1.0" encoding="UTF-8" ?>
<class name="Object" version="4.0">
	<brief_description>
		Base class for all non built-in types.
	</brief_description>
	<description>
		Every class which is not a built-in type inherits from this class.
		You can construct Objects from scripting languages, using [code]Object.new()[/code] in GDScript, [code]new Object[/code] in C#, or the "Construct Object" node in VisualScript.
		Objects do not manage memory. If a class inherits from Object, you will have to delete instances of it manually. To do so, call the [method free] method from your script or delete the instance from C++.
		Some classes that extend Object add memory management. This is the case of [Reference], which counts references and deletes itself automatically when no longer referenced. [Node], another fundamental type, deletes all its children when freed from memory.
		Objects export properties, which are mainly useful for storage and editing, but not really so much in programming. Properties are exported in [method _get_property_list] and handled in [method _get] and [method _set]. However, scripting languages and C++ have simpler means to export them.
		Property membership can be tested directly in GDScript using [code]in[/code]:
		[codeblock]
		var n = Node2D.new()
		print("position" in n) # Prints "True".
		print("other_property" in n) # Prints "False".
		[/codeblock]
		The [code]in[/code] operator will evaluate to [code]true[/code] as long as the key exists, even if the value is [code]null[/code].
		Objects also receive notifications. Notifications are a simple way to notify the object about different events, so they can all be handled together. See [method _notification].
		[b]Note:[/b] Unlike references to a [Reference], references to an Object stored in a variable can become invalid without warning. Therefore, it's recommended to use [Reference] for data classes instead of [Object].
	</description>
	<tutorials>
		<link title="When and how to avoid using nodes for everything">https://docs.godotengine.org/en/latest/getting_started/workflow/best_practices/node_alternatives.html</link>
	</tutorials>
	<methods>
		<method name="_get" qualifiers="virtual">
			<return type="Variant">
			</return>
			<argument index="0" name="property" type="StringName">
			</argument>
			<description>
				Virtual method which can be overridden to customize the return value of [method get].
				Returns the given property. Returns [code]null[/code] if the [code]property[/code] does not exist.
			</description>
		</method>
		<method name="_get_property_list" qualifiers="virtual">
			<return type="Array">
			</return>
			<description>
				Virtual method which can be overridden to customize the return value of [method get_property_list].
				Returns the object's property list as an [Array] of dictionaries.
				Each property's [Dictionary] must contain at least [code]name: String[/code] and [code]type: int[/code] (see [enum Variant.Type]) entries. Optionally, it can also include [code]hint: int[/code] (see [enum PropertyHint]), [code]hint_string: String[/code], and [code]usage: int[/code] (see [enum PropertyUsageFlags]).
			</description>
		</method>
		<method name="_init" qualifiers="virtual">
			<return type="void">
			</return>
			<description>
				Called when the object is initialized.
			</description>
		</method>
		<method name="_notification" qualifiers="virtual">
			<return type="void">
			</return>
			<argument index="0" name="what" type="int">
			</argument>
			<description>
				Called whenever the object receives a notification, which is identified in [code]what[/code] by a constant. The base [Object] has two constants [constant NOTIFICATION_POSTINITIALIZE] and [constant NOTIFICATION_PREDELETE], but subclasses such as [Node] define a lot more notifications which are also received by this method.
			</description>
		</method>
		<method name="_set" qualifiers="virtual">
			<return type="bool">
			</return>
			<argument index="0" name="property" type="StringName">
			</argument>
			<argument index="1" name="value" type="Variant">
			</argument>
			<description>
				Virtual method which can be overridden to customize the return value of [method set].
				Sets a property. Returns [code]true[/code] if the [code]property[/code] exists.
			</description>
		</method>
		<method name="_to_string" qualifiers="virtual">
			<return type="String">
			</return>
			<description>
				Virtual method which can be overridden to customize the return value of [method to_string], and thus the object's representation where it is converted to a string, e.g. with [code]print(obj)[/code].
				Returns a [String] representing the object. If not overridden, defaults to [code]"[ClassName:RID]"[/code].
			</description>
		</method>
		<method name="add_user_signal">
			<return type="void">
			</return>
			<argument index="0" name="signal" type="String">
			</argument>
			<argument index="1" name="arguments" type="Array" default="[  ]">
			</argument>
			<description>
				Adds a user-defined [code]signal[/code]. Arguments are optional, but can be added as an [Array] of dictionaries, each containing [code]name: String[/code] and [code]type: int[/code] (see [enum Variant.Type]) entries.
			</description>
		</method>
		<method name="call" qualifiers="vararg">
			<return type="Variant">
			</return>
			<argument index="0" name="method" type="StringName">
			</argument>
			<description>
				Calls the [code]method[/code] on the object and returns the result. This method supports a variable number of arguments, so parameters are passed as a comma separated list. Example:
				[codeblock]
				call("set", "position", Vector2(42.0, 0.0))
				[/codeblock]
				[b]Note:[/b] In C#, the method name must be specified as snake_case if it is defined by a built-in Godot node. This doesn't apply to user-defined methods where you should use the same convention as in the C# source (typically PascalCase).
			</description>
		</method>
		<method name="call_deferred" qualifiers="vararg">
			<return type="void">
			</return>
			<argument index="0" name="method" type="StringName">
			</argument>
			<description>
				Calls the [code]method[/code] on the object during idle time. This method supports a variable number of arguments, so parameters are passed as a comma separated list. Example:
				[codeblock]
				call_deferred("set", "position", Vector2(42.0, 0.0))
				[/codeblock]
				[b]Note:[/b] In C#, the method name must be specified as snake_case if it is defined by a built-in Godot node. This doesn't apply to user-defined methods where you should use the same convention as in the C# source (typically PascalCase).
			</description>
		</method>
		<method name="callv">
			<return type="Variant">
			</return>
			<argument index="0" name="method" type="StringName">
			</argument>
			<argument index="1" name="arg_array" type="Array">
			</argument>
			<description>
				Calls the [code]method[/code] on the object and returns the result. Contrarily to [method call], this method does not support a variable number of arguments but expects all parameters to be via a single [Array].
				[codeblock]
				callv("set", [ "position", Vector2(42.0, 0.0) ])
				[/codeblock]
			</description>
		</method>
		<method name="can_translate_messages" qualifiers="const">
			<return type="bool">
			</return>
			<description>
				Returns [code]true[/code] if the object can translate strings. See [method set_message_translation] and [method tr].
			</description>
		</method>
		<method name="connect">
			<return type="int" enum="Error">
			</return>
			<argument index="0" name="signal" type="StringName">
			</argument>
			<argument index="1" name="callable" type="Callable">
			</argument>
			<argument index="2" name="binds" type="Array" default="[  ]">
			</argument>
			<argument index="3" name="flags" type="int" default="0">
			</argument>
			<description>
				[b]FIXME:[/b] The syntax changed with the addition of [Callable], this should be updated.
				Connects a [code]signal[/code] to a [code]method[/code] on a [code]target[/code] object. Pass optional [code]binds[/code] to the call as an [Array] of parameters. These parameters will be passed to the method after any parameter used in the call to [method emit_signal]. Use [code]flags[/code] to set deferred or one-shot connections. See [enum ConnectFlags] constants.
				A [code]signal[/code] can only be connected once to a [code]method[/code]. It will throw an error if already connected, unless the signal was connected with [constant CONNECT_REFERENCE_COUNTED]. To avoid this, first, use [method is_connected] to check for existing connections.
				If the [code]target[/code] is destroyed in the game's lifecycle, the connection will be lost.
				Examples:
				[codeblock]
				connect("pressed", self, "_on_Button_pressed") # BaseButton signal
				connect("text_entered", self, "_on_LineEdit_text_entered") # LineEdit signal
				connect("hit", self, "_on_Player_hit", [ weapon_type, damage ]) # User-defined signal
				[/codeblock]
				An example of the relationship between [code]binds[/code] passed to [method connect] and parameters used when calling [method emit_signal]:
				[codeblock]
				connect("hit", self, "_on_Player_hit", [ weapon_type, damage ]) # weapon_type and damage are passed last
				emit_signal("hit", "Dark lord", 5) # "Dark lord" and 5 are passed first
				func _on_Player_hit(hit_by, level, weapon_type, damage):
				    print("Hit by %s (lvl %d) with weapon %s for %d damage" % [hit_by, level, weapon_type, damage])
				[/codeblock]
			</description>
		</method>
		<method name="disconnect">
			<return type="void">
			</return>
			<argument index="0" name="signal" type="StringName">
			</argument>
			<argument index="1" name="callable" type="Callable">
			</argument>
			<description>
				[b]FIXME:[/b] The syntax changed with the addition of [Callable], this should be updated.
				Disconnects a [code]signal[/code] from a [code]method[/code] on the given [code]target[/code].
				If you try to disconnect a connection that does not exist, the method will throw an error. Use [method is_connected] to ensure that the connection exists.
			</description>
		</method>
		<method name="emit_signal" qualifiers="vararg">
			<return type="void">
			</return>
			<argument index="0" name="signal" type="StringName">
			</argument>
			<description>
				Emits the given [code]signal[/code]. The signal must exist, so it should be a built-in signal of this class or one of its parent classes, or a user-defined signal. This method supports a variable number of arguments, so parameters are passed as a comma separated list. Example:
				[codeblock]
				emit_signal("hit", weapon_type, damage)
				emit_signal("game_over")
				[/codeblock]
			</description>
		</method>
		<method name="free">
			<return type="void">
			</return>
			<description>
				Deletes the object from memory. Any pre-existing reference to the freed object will become invalid, e.g. [code]is_instance_valid(object)[/code] will return [code]false[/code].
			</description>
		</method>
		<method name="get" qualifiers="const">
			<return type="Variant">
			</return>
			<argument index="0" name="property" type="String">
			</argument>
			<description>
				Returns the [Variant] value of the given [code]property[/code]. If the [code]property[/code] doesn't exist, this will return [code]null[/code].
				[b]Note:[/b] In C#, the property name must be specified as snake_case if it is defined by a built-in Godot node. This doesn't apply to user-defined properties where you should use the same convention as in the C# source (typically PascalCase).
			</description>
		</method>
		<method name="get_class" qualifiers="const">
			<return type="String">
			</return>
			<description>
				Returns the object's class as a [String].
			</description>
		</method>
		<method name="get_incoming_connections" qualifiers="const">
			<return type="Array">
			</return>
			<description>
				Returns an [Array] of dictionaries with information about signals that are connected to the object.
				Each [Dictionary] contains three String entries:
				- [code]source[/code] is a reference to the signal emitter.
				- [code]signal_name[/code] is the name of the connected signal.
				- [code]method_name[/code] is the name of the method to which the signal is connected.
			</description>
		</method>
		<method name="get_indexed" qualifiers="const">
			<return type="Variant">
			</return>
			<argument index="0" name="property" type="NodePath">
			</argument>
			<description>
				Gets the object's property indexed by the given [NodePath]. The node path should be relative to the current object and can use the colon character ([code]:[/code]) to access nested properties. Examples: [code]"position:x"[/code] or [code]"material:next_pass:blend_mode"[/code].
			</description>
		</method>
		<method name="get_instance_id" qualifiers="const">
			<return type="int">
			</return>
			<description>
				Returns the object's unique instance ID.
				This ID can be saved in [EncodedObjectAsID], and can be used to retrieve the object instance with [method @GlobalScope.instance_from_id].
			</description>
		</method>
		<method name="get_meta" qualifiers="const">
			<return type="Variant">
			</return>
			<argument index="0" name="name" type="String">
			</argument>
			<description>
				Returns the object's metadata entry for the given [code]name[/code].
			</description>
		</method>
		<method name="get_meta_list" qualifiers="const">
			<return type="PackedStringArray">
			</return>
			<description>
				Returns the object's metadata as a [PackedStringArray].
			</description>
		</method>
		<method name="get_method_list" qualifiers="const">
			<return type="Array">
			</return>
			<description>
				Returns the object's methods and their signatures as an [Array].
			</description>
		</method>
		<method name="get_property_list" qualifiers="const">
			<return type="Array">
			</return>
			<description>
				Returns the object's property list as an [Array] of dictionaries.
				Each property's [Dictionary] contain at least [code]name: String[/code] and [code]type: int[/code] (see [enum Variant.Type]) entries. Optionally, it can also include [code]hint: int[/code] (see [enum PropertyHint]), [code]hint_string: String[/code], and [code]usage: int[/code] (see [enum PropertyUsageFlags]).
			</description>
		</method>
		<method name="get_script" qualifiers="const">
			<return type="Variant">
			</return>
			<description>
				Returns the object's [Script] instance, or [code]null[/code] if none is assigned.
			</description>
		</method>
		<method name="get_signal_connection_list" qualifiers="const">
			<return type="Array">
			</return>
			<argument index="0" name="signal" type="String">
			</argument>
			<description>
				Returns an [Array] of connections for the given [code]signal[/code].
			</description>
		</method>
		<method name="get_signal_list" qualifiers="const">
			<return type="Array">
			</return>
			<description>
				Returns the list of signals as an [Array] of dictionaries.
			</description>
		</method>
		<method name="has_meta" qualifiers="const">
			<return type="bool">
			</return>
			<argument index="0" name="name" type="String">
			</argument>
			<description>
				Returns [code]true[/code] if a metadata entry is found with the given [code]name[/code].
			</description>
		</method>
		<method name="has_method" qualifiers="const">
			<return type="bool">
			</return>
			<argument index="0" name="method" type="StringName">
			</argument>
			<description>
				Returns [code]true[/code] if the object contains the given [code]method[/code].
			</description>
		</method>
		<method name="has_signal" qualifiers="const">
			<return type="bool">
			</return>
			<argument index="0" name="signal" type="StringName">
			</argument>
			<description>
				Returns [code]true[/code] if the given [code]signal[/code] exists.
			</description>
		</method>
		<method name="has_user_signal" qualifiers="const">
			<return type="bool">
			</return>
			<argument index="0" name="signal" type="StringName">
			</argument>
			<description>
				Returns [code]true[/code] if the given user-defined [code]signal[/code] exists. Only signals added using [method add_user_signal] are taken into account.
			</description>
		</method>
		<method name="is_blocking_signals" qualifiers="const">
			<return type="bool">
			</return>
			<description>
				Returns [code]true[/code] if signal emission blocking is enabled.
			</description>
		</method>
		<method name="is_class" qualifiers="const">
			<return type="bool">
			</return>
			<argument index="0" name="class" type="String">
			</argument>
			<description>
				Returns [code]true[/code] if the object inherits from the given [code]class[/code].
			</description>
		</method>
		<method name="is_connected" qualifiers="const">
			<return type="bool">
			</return>
			<argument index="0" name="signal" type="StringName">
			</argument>
			<argument index="1" name="callable" type="Callable">
			</argument>
			<description>
				[b]FIXME:[/b] The syntax changed with the addition of [Callable], this should be updated.
				Returns [code]true[/code] if a connection exists for a given [code]signal[/code], [code]target[/code], and [code]method[/code].
			</description>
		</method>
		<method name="is_queued_for_deletion" qualifiers="const">
			<return type="bool">
			</return>
			<description>
				Returns [code]true[/code] if the [method Node.queue_free] method was called for the object.
			</description>
		</method>
		<method name="notification">
			<return type="void">
			</return>
			<argument index="0" name="what" type="int">
			</argument>
			<argument index="1" name="reversed" type="bool" default="false">
			</argument>
			<description>
				Send a given notification to the object, which will also trigger a call to the [method _notification] method of all classes that the object inherits from.
				If [code]reversed[/code] is [code]true[/code], [method _notification] is called first on the object's own class, and then up to its successive parent classes. If [code]reversed[/code] is [code]false[/code], [method _notification] is called first on the highest ancestor ([Object] itself), and then down to its successive inheriting classes.
			</description>
		</method>
		<method name="property_list_changed_notify">
			<return type="void">
			</return>
			<description>
				Notify the editor that the property list has changed, so that editor plugins can take the new values into account. Does nothing on export builds.
			</description>
		</method>
		<method name="remove_meta">
			<return type="void">
			</return>
			<argument index="0" name="name" type="String">
			</argument>
			<description>
				Removes a given entry from the object's metadata. See also [method set_meta].
			</description>
		</method>
		<method name="set">
			<return type="void">
			</return>
			<argument index="0" name="property" type="String">
			</argument>
			<argument index="1" name="value" type="Variant">
			</argument>
			<description>
				Assigns a new value to the given property. If the [code]property[/code] does not exist, nothing will happen.
				[b]Note:[/b] In C#, the property name must be specified as snake_case if it is defined by a built-in Godot node. This doesn't apply to user-defined properties where you should use the same convention as in the C# source (typically PascalCase).
			</description>
		</method>
		<method name="set_block_signals">
			<return type="void">
			</return>
			<argument index="0" name="enable" type="bool">
			</argument>
			<description>
				If set to [code]true[/code], signal emission is blocked.
			</description>
		</method>
		<method name="set_deferred">
			<return type="void">
			</return>
			<argument index="0" name="property" type="StringName">
			</argument>
			<argument index="1" name="value" type="Variant">
			</argument>
			<description>
				Assigns a new value to the given property, after the current frame's physics step. This is equivalent to calling [method set] via [method call_deferred], i.e. [code]call_deferred("set", property, value)[/code].
				[b]Note:[/b] In C#, the property name must be specified as snake_case if it is defined by a built-in Godot node. This doesn't apply to user-defined properties where you should use the same convention as in the C# source (typically PascalCase).
			</description>
		</method>
		<method name="set_indexed">
			<return type="void">
			</return>
			<argument index="0" name="property" type="NodePath">
			</argument>
			<argument index="1" name="value" type="Variant">
			</argument>
			<description>
				Assigns a new value to the property identified by the [NodePath]. The node path should be relative to the current object and can use the colon character ([code]:[/code]) to access nested properties. Example:
				[codeblock]
				set_indexed("position", Vector2(42, 0))
				set_indexed("position:y", -10)
				print(position) # (42, -10)
				[/codeblock]
			</description>
		</method>
		<method name="set_message_translation">
			<return type="void">
			</return>
			<argument index="0" name="enable" type="bool">
			</argument>
			<description>
				Defines whether the object can translate strings (with calls to [method tr]). Enabled by default.
			</description>
		</method>
		<method name="set_meta">
			<return type="void">
			</return>
			<argument index="0" name="name" type="String">
			</argument>
			<argument index="1" name="value" type="Variant">
			</argument>
			<description>
				Adds, changes or removes a given entry in the object's metadata. Metadata are serialized and can take any [Variant] value.
				To remove a given entry from the object's metadata, use [method remove_meta]. Metadata is also removed if its value is set to [code]null[/code]. This means you can also use [code]set_meta("name", null)[/code] to remove metadata for [code]"name"[/code].
			</description>
		</method>
		<method name="set_script">
			<return type="void">
			</return>
			<argument index="0" name="script" type="Variant">
			</argument>
			<description>
				Assigns a script to the object. Each object can have a single script assigned to it, which are used to extend its functionality.
				If the object already had a script, the previous script instance will be freed and its variables and state will be lost. The new script's [method _init] method will be called.
			</description>
		</method>
		<method name="to_string">
			<return type="String">
			</return>
			<description>
				Returns a [String] representing the object. If not overridden, defaults to [code]"[ClassName:RID]"[/code].
				Override the method [method _to_string] to customize the [String] representation.
			</description>
		</method>
		<method name="tr" qualifiers="const">
			<return type="String">
			</return>
			<argument index="0" name="message" type="StringName">
			</argument>
			<argument index="1" name="context" type="StringName" default="&quot;&quot;">
			</argument>
			<description>
				Translates a message using translation catalogs configured in the Project Settings. An additional context could be used to specify the translation context.
				Only works if message translation is enabled (which it is by default), otherwise it returns the [code]message[/code] unchanged. See [method set_message_translation].
				See [url=https://docs.godotengine.org/en/latest/tutorials/i18n/internationalizing_games.html]Internationalizing games[/url] for examples of the usage of this method.
			</description>
		</method>
		<method name="tr_n" qualifiers="const">
			<return type="String">
			</return>
			<argument index="0" name="message" type="StringName">
			</argument>
			<argument index="1" name="plural_message" type="StringName">
			</argument>
			<argument index="2" name="n" type="int">
			</argument>
			<argument index="3" name="context" type="StringName" default="&quot;&quot;">
			</argument>
			<description>
				Translates a message involving plurals using translation catalogs configured in the Project Settings. An additional context could be used to specify the translation context.
				Only works if message translation is enabled (which it is by default), otherwise it returns the [code]message[/code] or [code]plural_message[/code] unchanged. See [method set_message_translation].
				The number [code]n[/code] is the number or quantity of the plural object. It will be used to guide the translation system to fetch the correct plural form for the selected language.
				[b]Note:[/b] Negative and floating-point values usually represent physical entities for which singular and plural don't clearly apply. In such cases, use [method tr].
				See [url=https://docs.godotengine.org/en/latest/tutorials/i18n/localization_using_gettext.html]Localization using gettext[/url] for examples of the usage of this method.
			</description>
		</method>
	</methods>
	<signals>
		<signal name="script_changed">
			<description>
				Emitted whenever the object's script is changed.
			</description>
		</signal>
	</signals>
	<constants>
		<constant name="NOTIFICATION_POSTINITIALIZE" value="0">
			Called right when the object is initialized. Not available in script.
		</constant>
		<constant name="NOTIFICATION_PREDELETE" value="1">
			Called before the object is about to be deleted.
		</constant>
		<constant name="CONNECT_DEFERRED" value="1" enum="ConnectFlags">
			Connects a signal in deferred mode. This way, signal emissions are stored in a queue, then set on idle time.
		</constant>
		<constant name="CONNECT_PERSIST" value="2" enum="ConnectFlags">
			Persisting connections are saved when the object is serialized to file.
		</constant>
		<constant name="CONNECT_ONESHOT" value="4" enum="ConnectFlags">
			One-shot connections disconnect themselves after emission.
		</constant>
		<constant name="CONNECT_REFERENCE_COUNTED" value="8" enum="ConnectFlags">
			Connect a signal as reference-counted. This means that a given signal can be connected several times to the same target, and will only be fully disconnected once no references are left.
		</constant>
	</constants>
</class>