WebProcessExtension

Added in version 2.40.

class WebProcessExtension(**properties: Any)

Superclasses: Object

Represents an extension of the web process.

WebKitWebProcessExtension is a loadable module for the web process. It allows you to execute code in the web process and being able to use the DOM API, to change any request or to inject custom JavaScript code, for example.

To create a WebKitWebProcessExtension you should write a module with an initialization function that could be either webkit_web_process_extension_initialize() with prototype WebKitWebProcessExtensionInitializeFunction or webkit_web_process_extension_initialize_with_user_data() with prototype WebKitWebProcessExtensionInitializeWithUserDataFunction. This function has to be public and it has to use the G_MODULE_EXPORT macro. It is called when the web process is initialized.

static void
web_page_created_callback (WebKitWebProcessExtension *extension,
                           WebKitWebPage             *web_page,
                           gpointer                   user_data)
{
    g_print ("Page ``%d`` created for ``%s``\n",
             webkit_web_page_get_id (web_page),
             webkit_web_page_get_uri (web_page));
}

G_MODULE_EXPORT void
webkit_web_process_extension_initialize (WebKitWebProcessExtension *extension)
{
    g_signal_connect (extension, "page-created",
                      G_CALLBACK (web_page_created_callback),
                      NULL);
}

The previous piece of code shows a trivial example of an extension that notifies when a WebPage is created.

WebKit has to know where it can find the created WebKitWebProcessExtension. To do so you should use the webkit_web_context_set_web_extensions_directory() function. The signal WebKitWebContext::initialize-web-extensions is the recommended place to call it.

To provide the initialization data used by the webkit_web_process_extension_initialize_with_user_data() function, you have to call webkit_web_context_set_web_extensions_initialization_user_data() with the desired data as parameter. You can see an example of this in the following piece of code:

``define`` WEB_EXTENSIONS_DIRECTORY // ...

static void
initialize_web_extensions (WebKitWebContext *context,
                           gpointer          user_data)
{
  // Web Extensions get a different ID for each Web Process
  static guint32 unique_id = 0;

  webkit_web_context_set_web_extensions_directory (
     context, WEB_EXTENSIONS_DIRECTORY);
  webkit_web_context_set_web_extensions_initialization_user_data (
     context, g_variant_new_uint32 (unique_id++));
}

int main (int argc, char **argv)
{
  g_signal_connect (webkit_web_context_get_default (),
                   "initialize-web-extensions",
                    G_CALLBACK (initialize_web_extensions),
                    NULL);

  GtkWidget *view = webkit_web_view_new ();

  // ...
}

Methods

class WebProcessExtension

get_page(page_id: int) → WebPage

Get the web page of the given page_id.

Added in version 2.40.

Parameters:

page_id – the identifier of the WebPage to get

send_message_to_context(message: UserMessage, cancellable: Cancellable | None = None, callback: Callable[[...], None] | None = None, *user_data: Any) → None

Send message to the WebKitWebContext corresponding to extension. If message is floating, it’s consumed.

If you don’t expect any reply, or you simply want to ignore it, you can pass None as calback. When the operation is finished, callback will be called. You can then call send_message_to_context_finish() to get the message reply.

Added in version 2.40.

Parameters:

• message – a UserMessage

• cancellable – a Cancellable or None to ignore

• callback – A AsyncReadyCallback to call when the request is satisfied or None

• user_data – the data to pass to callback function

send_message_to_context_finish(result: AsyncResult) → UserMessage

Finish an asynchronous operation started with send_message_to_context().

Added in version 2.40.

Parameters:

result – a AsyncResult

Signals

class WebProcessExtension.signals

page_created(web_page: WebPage) → None

This signal is emitted when a new WebPage is created in the Web Process.

Added in version 2.40.

Parameters:

web_page – the WebPage created

user_message_received(message: UserMessage) → None

This signal is emitted when a UserMessage is received from the WebKitWebContext corresponding to extension. Messages sent by WebKitWebContext are always broadcasted to all web extensions and they can’t be replied to. Calling send_reply() will do nothing.

Added in version 2.40.

Parameters:

message – the UserMessage received