JSCClass: JavaScriptCore GLib Reference Manual

## JSCClass JSCClass — JavaScript custom class |

## Functions

JSCValue * | (*JSCClassGetPropertyFunction) ()
gboolean | (*JSCClassSetPropertyFunction) ()
gboolean | (*JSCClassHasPropertyFunction) ()
gboolean | (*JSCClassDeletePropertyFunction) ()
gchar ** | (*JSCClassEnumeratePropertiesFunction) ()
const char * | jsc_class_get_name ()
JSCClass * | jsc_class_get_parent ()
JSCValue * | jsc_class_add_constructor ()
JSCValue * | jsc_class_add_constructorv ()
JSCValue * | jsc_class_add_constructor_variadic ()
void | jsc_class_add_method ()
void | jsc_class_add_methodv ()
void | jsc_class_add_method_variadic ()
void | jsc_class_add_property ()

## Properties

JSCContext * | context | Write / Construct Only
gchar * | name | Read / Write / Construct Only
JSCClass * | parent | Read / Write / Construct Only

## Types and Values

| JSCClass
| JSCClassVTable

## Object Hierarchy

        GObject
        ╰── JSCClass

## Description

A JSSClass represents a custom JavaScript class registered by the user in a JSCContext. It allows to create new JavaScripts objects whose instances are created by the user using this API. It's possible to add constructors, properties and methods for a JSSClass by providing GCallbacks to implement them.

## Functions

### JSCClassGetPropertyFunction ()

    JSCValue *
    (*JSCClassGetPropertyFunction) (JSCClass *jsc_class,
                                    JSCContext *context,
                                    gpointer instance,
                                    const char *name);

The type of get_property in JSCClassVTable. This is only required when you need to handle external properties not added to the prototype.

#### Parameters

jsc_class | a JSCClass |
context | a JSCContext |
instance | the `jsc_class` instance |
name | the property name |

#### Returns

a JSCValue or `NULL` to forward the request to the parent class or prototype chain.

[transfer full][nullable]

### JSCClassSetPropertyFunction ()

    gboolean
    (*JSCClassSetPropertyFunction) (JSCClass *jsc_class,
                                    JSCContext *context,
                                    gpointer instance,
                                    const char *name,
                                    JSCValue *value);

The type of set_property in JSCClassVTable. This is only required when you need to handle external properties not added to the prototype.

#### Parameters

jsc_class | a JSCClass |
context | a JSCContext |
instance | the `jsc_class` instance |
name | the property name |
value | the JSCValue to set |

#### Returns

`TRUE` if handled or `FALSE` to forward the request to the parent class or prototype chain.

### JSCClassHasPropertyFunction ()

    gboolean
    (*JSCClassHasPropertyFunction) (JSCClass *jsc_class,
                                    JSCContext *context,
                                    gpointer instance,
                                    const char *name);

The type of has_property in JSCClassVTable. This is only required when you need to handle external properties not added to the prototype.

#### Parameters

jsc_class | a JSCClass |
context | a JSCContext |
instance | the `jsc_class` instance |
name | the property name |

#### Returns

`TRUE` if `instance` has a property with `name` or `FALSE` to forward the request to the parent class or prototype chain.

### JSCClassDeletePropertyFunction ()

    gboolean
    (*JSCClassDeletePropertyFunction) (JSCClass *jsc_class,
                                       JSCContext *context,
                                       gpointer instance,
                                       const char *name);

The type of delete_property in JSCClassVTable. This is only required when you need to handle external properties not added to the prototype.

#### Parameters

jsc_class | a JSCClass |
context | a JSCContext |
instance | the `jsc_class` instance |
name | the property name |

#### Returns

`TRUE` if handled or `FALSE` to to forward the request to the parent class or prototype chain.

### JSCClassEnumeratePropertiesFunction ()

    gchar **
    (*JSCClassEnumeratePropertiesFunction)
                                   (JSCClass *jsc_class,
                                    JSCContext *context,
                                    gpointer instance);

The type of enumerate_properties in JSCClassVTable. This is only required when you need to handle external properties not added to the prototype.

#### Parameters

jsc_class | a JSCClass |
context | a JSCContext |
instance | the `jsc_class` instance |

#### Returns

a `NULL`-terminated array of strings containing the property names, or `NULL` if `instance` doesn't have enumerable properties.

[array zero-terminated=1][transfer full][nullable]

### jsc_class_get_name ()

    const char *
    jsc_class_get_name (JSCClass *jsc_class);

Get the class name of `jsc_class`

#### Parameters

jsc_class | a `JSCClass` |

#### Returns

the name of `jsc_class` .

[transfer none]

### jsc_class_get_parent ()

    JSCClass *
    jsc_class_get_parent (JSCClass *jsc_class);

Get the parent class of `jsc_class`

#### Parameters

jsc_class | a `JSCClass` |

#### Returns

the parent class of `jsc_class` .

[transfer none]

### jsc_class_add_constructor ()

    JSCValue *
    jsc_class_add_constructor (JSCClass *jsc_class,
                               const char *name,
                               GCallback callback,
                               gpointer user_data,
                               GDestroyNotify destroy_notify,
                               GType return_type,
                               guint n_params,
                               ...);

Add a constructor to `jsc_class` . If `name` is `NULL`, the class name will be used. When `new` is used with the constructor or `jsc_value_constructor_call()` is called, `callback` is invoked receiving the parameters and `user_data` as the last parameter. When the constructor object is cleared in the JSCClass context, `destroy_notify` is called with `user_data` as parameter.

This function creates the constructor, which needs to be added to an object as a property to be able to use it. Use `jsc_context_set_value()` to make the constructor available in the global object.

Note that the value returned by `callback` is adopted by `jsc_class` , and the GDestroyNotify passed to `jsc_context_register_class()` is responsible for disposing of it.

[skip]

#### Parameters

jsc_class | a JSCClass |
name | the constructor name or `NULL`. | [nullable]
callback | a GCallback to be called to create an instance of `jsc_class` . | [scope async]
user_data | user data to pass to `callback` . | [closure]
destroy_notify | destroy notifier for `user_data` . | [nullable]
return_type | the GType of the constructor return value |
n_params | the number of parameter types to follow or 0 if constructor doesn't receive parameters. |
... | a list of GTypes, one for each parameter. |

#### Returns

a JSCValue representing the class constructor.

[transfer full]

### jsc_class_add_constructorv ()

    JSCValue *
    jsc_class_add_constructorv (JSCClass *jsc_class,
                                const char *name,
                                GCallback callback,
                                gpointer user_data,
                                GDestroyNotify destroy_notify,
                                GType return_type,
                                guint n_parameters,
                                GType *parameter_types);

Add a constructor to `jsc_class` . If `name` is `NULL`, the class name will be used. When `new` is used with the constructor or `jsc_value_constructor_call()` is called, `callback` is invoked receiving the parameters and `user_data` as the last parameter. When the constructor object is cleared in the JSCClass context, `destroy_notify` is called with `user_data` as parameter.

This function creates the constructor, which needs to be added to an object as a property to be able to use it. Use `jsc_context_set_value()` to make the constructor available in the global object.

Note that the value returned by `callback` is adopted by `jsc_class` , and the GDestroyNotify passed to `jsc_context_register_class()` is responsible for disposing of it.

[rename-to jsc_class_add_constructor]

#### Parameters

jsc_class | a JSCClass |
name | the constructor name or `NULL`. | [nullable]
callback | a GCallback to be called to create an instance of `jsc_class` . | [scope async]
user_data | user data to pass to `callback` . | [closure]
destroy_notify | destroy notifier for `user_data` . | [nullable]
return_type | the GType of the constructor return value |
n_parameters | the number of parameters |
parameter_types | a list of GTypes, one for each parameter, or `NULL`. | [nullable][array length=n_parameters][element-type GType]

#### Returns

a JSCValue representing the class constructor.

[transfer full]

### jsc_class_add_constructor_variadic ()

    JSCValue *
    jsc_class_add_constructor_variadic (JSCClass *jsc_class,
                                        const char *name,
                                        GCallback callback,
                                        gpointer user_data,
                                        GDestroyNotify destroy_notify,
                                        GType return_type);

Add a constructor to `jsc_class` . If `name` is `NULL`, the class name will be used. When `new` is used with the constructor or `jsc_value_constructor_call()` is called, `callback` is invoked receiving a GPtrArray of JSCValues as arguments and `user_data` as the last parameter. When the constructor object is cleared in the JSCClass context, `destroy_notify` is called with `user_data` as parameter.

This function creates the constructor, which needs to be added to an object as a property to be able to use it. Use `jsc_context_set_value()` to make the constructor available in the global object.

Note that the value returned by `callback` is adopted by `jsc_class` , and the GDestroyNotify passed to `jsc_context_register_class()` is responsible for disposing of it.

#### Parameters

jsc_class | a JSCClass |
name | the constructor name or `NULL`. | [nullable]
callback | a GCallback to be called to create an instance of `jsc_class` . | [scope async]
user_data | user data to pass to `callback` . | [closure]
destroy_notify | destroy notifier for `user_data` . | [nullable]
return_type | the GType of the constructor return value |

#### Returns

a JSCValue representing the class constructor.

[transfer full]

### jsc_class_add_method ()

    void
    jsc_class_add_method (JSCClass *jsc_class,
                          const char *name,
                          GCallback callback,
                          gpointer user_data,
                          GDestroyNotify destroy_notify,
                          GType return_type,
                          guint n_params,
                          ...);

Add method with `name` to `jsc_class` . When the method is called by JavaScript or `jsc_value_object_invoke_method()`, `callback` is called receiving the class instance as first parameter, followed by the method parameters and then `user_data` as last parameter. When the method is cleared in the JSCClass context, `destroy_notify` is called with `user_data` as parameter.

Note that the value returned by `callback` must be transfer full. In case of non-refcounted boxed types, you should use `G_TYPE_POINTER` instead of the actual boxed GType to ensure that the instance owned by JSCClass is used. If you really want to return a new copy of the boxed type, use JSC_TYPE_VALUE and return a JSCValue created with `jsc_value_new_object()` that receives the copy as the instance parameter.

[skip]

#### Parameters

jsc_class | a JSCClass |
name | the method name |
callback | a GCallback to be called to invoke method `name` of `jsc_class` . | [scope async]
user_data | user data to pass to `callback` . | [closure]
destroy_notify | destroy notifier for `user_data` . | [nullable]
return_type | the GType of the method return value, or `G_TYPE_NONE` if the method is void. |
n_params | the number of parameter types to follow or 0 if the method doesn't receive parameters. |
... | a list of GTypes, one for each parameter. |

### jsc_class_add_methodv ()

    void
    jsc_class_add_methodv (JSCClass *jsc_class,
                           const char *name,
                           GCallback callback,
                           gpointer user_data,
                           GDestroyNotify destroy_notify,
                           GType return_type,
                           guint n_parameters,
                           GType *parameter_types);

Add method with `name` to `jsc_class` . When the method is called by JavaScript or `jsc_value_object_invoke_method()`, `callback` is called receiving the class instance as first parameter, followed by the method parameters and then `user_data` as last parameter. When the method is cleared in the JSCClass context, `destroy_notify` is called with `user_data` as parameter.

Note that the value returned by `callback` must be transfer full. In case of non-refcounted boxed types, you should use `G_TYPE_POINTER` instead of the actual boxed GType to ensure that the instance owned by JSCClass is used. If you really want to return a new copy of the boxed type, use JSC_TYPE_VALUE and return a JSCValue created with `jsc_value_new_object()` that receives the copy as the instance parameter.

[rename-to jsc_class_add_method]

#### Parameters

jsc_class | a JSCClass |
name | the method name |
callback | a GCallback to be called to invoke method `name` of `jsc_class` . | [scope async]
user_data | user data to pass to `callback` . | [closure]
destroy_notify | destroy notifier for `user_data` . | [nullable]
return_type | the GType of the method return value, or `G_TYPE_NONE` if the method is void. |
n_parameters | the number of parameter types to follow or 0 if the method doesn't receive parameters. |
parameter_types | a list of GTypes, one for each parameter, or `NULL`. | [nullable][array length=n_parameters][element-type GType]

### jsc_class_add_method_variadic ()

    void
    jsc_class_add_method_variadic (JSCClass *jsc_class,
                                   const char *name,
                                   GCallback callback,
                                   gpointer user_data,
                                   GDestroyNotify destroy_notify,
                                   GType return_type);

Add method with `name` to `jsc_class` . When the method is called by JavaScript or `jsc_value_object_invoke_method()`, `callback` is called receiving the class instance as first parameter, followed by a GPtrArray of JSCValues with the method arguments and then `user_data` as last parameter. When the method is cleared in the JSCClass context, `destroy_notify` is called with `user_data` as parameter.

Note that the value returned by `callback` must be transfer full. In case of non-refcounted boxed types, you should use `G_TYPE_POINTER` instead of the actual boxed GType to ensure that the instance owned by JSCClass is used. If you really want to return a new copy of the boxed type, use JSC_TYPE_VALUE and return a JSCValue created with `jsc_value_new_object()` that receives the copy as the instance parameter.

#### Parameters

jsc_class | a JSCClass |
name | the method name |
callback | a GCallback to be called to invoke method `name` of `jsc_class` . | [scope async]
user_data | user data to pass to `callback` . | [closure]
destroy_notify | destroy notifier for `user_data` . | [nullable]
return_type | the GType of the method return value, or `G_TYPE_NONE` if the method is void. |

### jsc_class_add_property ()

    void
    jsc_class_add_property (JSCClass *jsc_class,
                            const char *name,
                            GType property_type,
                            GCallback getter,
                            GCallback setter,
                            gpointer user_data,
                            GDestroyNotify destroy_notify);

Add a property with `name` to `jsc_class` . When the property value needs to be getted, `getter` is called receiving the the class instance as first parameter and `user_data` as last parameter. When the property value needs to be set, `setter` is called receiving the the class instance as first parameter, followed by the value to be set and then `user_data` as the last parameter. When the property is cleared in the JSCClass context, `destroy_notify` is called with `user_data` as parameter.

Note that the value returned by `getter` must be transfer full. In case of non-refcounted boxed types, you should use `G_TYPE_POINTER` instead of the actual boxed GType to ensure that the instance owned by JSCClass is used. If you really want to return a new copy of the boxed type, use JSC_TYPE_VALUE and return a JSCValue created with `jsc_value_new_object()` that receives the copy as the instance parameter.

#### Parameters

jsc_class | a JSCClass |
name | the property name |
property_type | the GType of the property value |
getter | a GCallback to be called to get the property value. | [scope async][nullable]
setter | a GCallback to be called to set the property value. | [scope async][nullable]
user_data | user data to pass to `getter` and `setter` . | [closure]
destroy_notify | destroy notifier for `user_data` . | [nullable]

## Types and Values

### JSCClass

    typedef struct _JSCClass JSCClass;

### JSCClassVTable

    typedef struct {
        JSCClassGetPropertyFunction get_property;
        JSCClassSetPropertyFunction set_property;
        JSCClassHasPropertyFunction has_property;
        JSCClassDeletePropertyFunction delete_property;
        JSCClassEnumeratePropertiesFunction enumerate_properties;
    } JSCClassVTable;

Virtual table for a JSCClass. This can be optionally used when registering a JSCClass in a JSCContext to provide a custom implementation for the class. All virtual functions are optional and can be set to `NULL` to fallback to the default implementation.

#### Members

JSCClassGetPropertyFunction `get_property`; | a JSCClassGetPropertyFunction for getting a property. |
JSCClassSetPropertyFunction `set_property`; | a JSCClassSetPropertyFunction for setting a property. |
JSCClassHasPropertyFunction `has_property`; | a JSCClassHasPropertyFunction for querying a property. |
JSCClassDeletePropertyFunction `delete_property`; | a JSCClassDeletePropertyFunction for deleting a property. |
JSCClassEnumeratePropertiesFunction `enumerate_properties`; | a JSCClassEnumeratePropertiesFunction for enumerating properties. |

## Property Details

### The `“context”` property

      “context”                  JSCContext *

The JSCContext in which the class was registered.

Flags: Write / Construct Only

### The `“name”` property

      “name”                     gchar *

The name of the class.

Flags: Read / Write / Construct Only

Default value: NULL

### The `“parent”` property

      “parent”                   JSCClass *

The parent class or `NULL` in case of final classes.

Flags: Read / Write / Construct Only

## See Also

JSCContext