alias Gio::DBusMessageFilterFunction


Signature for function used in g_dbus_connection_add_filter().

A filter function is passed a #GDBusMessage and expected to return a #GDBusMessage too. Passive filter functions that don't modify the message can simply return the message object: |[ static GDBusMessage * passive_filter (GDBusConnection *connection GDBusMessage *message, gboolean incoming, gpointer user_data) { // inspect message return message; } ]| Filter functions that wants to drop a message can simply return nil: |[ static GDBusMessage * drop_filter (GDBusConnection *connection GDBusMessage *message, gboolean incoming, gpointer user_data) { if (should_drop_message) { g_object_unref (message); message = NULL; } return message; } ]| Finally, a filter function may modify a message by copying it: |[ static GDBusMessage * modifying_filter (GDBusConnection *connection GDBusMessage *message, gboolean incoming, gpointer user_data) { GDBusMessage *copy; GError *error;

error = NULL; copy = g_dbus_message_copy (message, &error); // handle error being set g_object_unref (message);

// modify copy

return copy; } ]| If the returned #GDBusMessage is different from message and cannot be sent on connection (it could use features, such as file descriptors, not compatible with connection), then a warning is logged to standard error. Applications can check this ahead of time using g_dbus_message_to_blob() passing a #GDBusCapabilityFlags value obtained from connection.

Alias Definition

Gio::DBusConnection, Gio::DBusMessage, Bool -> Gio::DBusMessage

Defined in: