JavaScriptCore.Value.new_function
Description: Reference for JavaScriptCore.Value.new_function

### Constructor

# JavaScriptCore Valuenew_function

#### Declaration [src]

    JSCValue*
    jsc_value_new_function (
      JSCContext* context,
      const char* name,
      GCallback callback,
      gpointer user_data,
      GDestroyNotify destroy_notify,
      GType return_type,
      guint n_params,
      ...
    )

#### Description [src]

Create a function in `context`. If `name` is `NULL` an anonymous function will be created. When the function is called by JavaScript or jsc_value_function_call(), `callback` is called receiving the function parameters and then `user_data` as last parameter. When the function is cleared in `context`, `destroy_notify` is called with `user_data` as parameter.

Note that the value returned by `callback` must be fully transferred. In case of boxed types, you could 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 instance parameter.

This constructor is not directly available to language bindings

#### Parameters

`context` | `JSCContext`
| A `JSCContext`:
| The data is owned by the caller of the function.
`name` | `const char*`
| The function name or `NULL`.
| The argument can be `NULL`.
| The data is owned by the caller of the function.
| The value is a NUL terminated UTF-8 string.
`callback` | `GCallback`
| A `GCallback`.
`user_data` | `gpointer`
| User data to pass to `callback`.
| The argument can be `NULL`.
| The data is owned by the caller of the function.
`destroy_notify` | `GDestroyNotify`
| Destroy notifier for `user_data`.
| The argument can be `NULL`.
`return_type` | `GType`
| The `GType` of the function return value, or `G_TYPE_NONE` if the function is void.
`n_params` | `guint`
| The number of parameter types to follow or 0 if the function doesn’t receive parameters.
`...` | ``
| A list of `GType`s, one for each parameter.

#### Return value

Returns: | `JSCValue`
| A `JSCValue`.
| The caller of the function takes ownership of the data, and is responsible for freeing it.