## TpBaseConnection

TpBaseConnection — base class for TpSvcConnection implementations

## Synopsis

    #include <telepathy-glib/base-connection.h>

    #define             TP_INTERNAL_CONNECTION_STATUS_NEW
                        TpBaseConnection;
                        TpBaseConnectionClass;
    GPtrArray *         (*TpBaseConnectionCreateChannelFactoriesImpl)
                                                            (TpBaseConnection *self);
    GPtrArray *         (*TpBaseConnectionCreateChannelManagersImpl)
                                                            (TpBaseConnection *self);
    void                (*TpBaseConnectionCreateHandleReposImpl)
                                                            (TpBaseConnection *self,
                                                             TpHandleRepoIface *repos[NUM_TP_HANDLE_TYPES]);
    gchar *             (*TpBaseConnectionGetUniqueConnectionNameImpl)
                                                            (TpBaseConnection *self);
    void                (*TpBaseConnectionProc)             (TpBaseConnection *self);
    gboolean            (*TpBaseConnectionStartConnectingImpl)
                                                            (TpBaseConnection *self,
                                                             GError **error);
    gboolean            tp_base_connection_register         (TpBaseConnection *self,
                                                             const gchar *cm_name,
                                                             gchar **bus_name,
                                                             gchar **object_path,
                                                             GError **error);
    TpHandleRepoIface * tp_base_connection_get_handles      (TpBaseConnection *self,
                                                             TpHandleType handle_type);
    TpHandle            tp_base_connection_get_self_handle  (TpBaseConnection *self);
    void                tp_base_connection_set_self_handle  (TpBaseConnection *self,
                                                             TpHandle self_handle);
    void                tp_base_connection_change_status    (TpBaseConnection *self,
                                                             TpConnectionStatus status,
                                                             TpConnectionStatusReason reason);
    void                tp_base_connection_disconnect_with_dbus_error
                                                            (TpBaseConnection *self,
                                                             const gchar *error_name,
                                                             GHashTable *details,
                                                             TpConnectionStatusReason reason);
    void                tp_base_connection_finish_shutdown  (TpBaseConnection *self);
    void                tp_base_connection_add_interfaces   (TpBaseConnection *self,
                                                             const gchar **interfaces);
    void                tp_base_connection_dbus_request_handles
                                                            (TpSvcConnection *iface,
                                                             guint handle_type,
                                                             const gchar **names,
                                                             DBusGMethodInvocation *context);
    #define             TP_BASE_CONNECTION_ERROR_IF_NOT_CONNECTED(conn, context)
    void                tp_base_connection_register_with_contacts_mixin
                                                            (TpBaseConnection *self);

                        TpChannelManagerIter;
    void                tp_base_connection_channel_manager_iter_init
                                                            (TpChannelManagerIter *iter,
                                                             TpBaseConnection *self);
    gboolean            tp_base_connection_channel_manager_iter_next
                                                            (TpChannelManagerIter *iter,
                                                             TpChannelManager **manager_out);

## Object Hierarchy

      GObject
       +----TpBaseConnection

## Implemented Interfaces

TpBaseConnection implements TpSvcConnection, TpSvcDBusProperties and TpSvcConnectionInterfaceRequests.

## Properties

      "protocol"                 gchar*                : Read / Write / Construct Only
      "self-handle"              guint                 : Read / Write

## Signals

      "shutdown-finished"                              : Run Last / Has Details

## Description

This base class makes it easier to write TpSvcConnection implementations by managing connection status, channel factories and handle tracking. A subclass should often not need to implement any of the Connection methods itself.

However, methods may be reimplemented if needed: for instance, Gabble overrides RequestHandles so it can validate MUC rooms, which must be done asynchronously.

## Details

### TP_INTERNAL_CONNECTION_STATUS_NEW

    #   define TP_INTERNAL_CONNECTION_STATUS_NEW ((TpConnectionStatus)(-1))

A special value for TpConnectionStatus, used within GLib connection managers to indicate that the connection is disconnected because connection has never been attempted (as distinct from disconnected after connection has started, either by user request or an error).

Must never be visible on the D-Bus - `TP_CONNECTION_STATUS_DISCONNECTED` is sent instead.

### TpBaseConnection

    typedef struct {
        GObject parent;

        gchar *bus_name;
        gchar *object_path;

        TpConnectionStatus status;

        TpHandle self_handle;
    } TpBaseConnection;

Data structure representing a generic TpSvcConnection implementation.

In addition to the fields documented here, there are four gpointer fields which must currently be `NULL` (a meaning may be defined for these in a future version of telepathy-glib), and a pointer to opaque private data.

GObject `parent`; | Fields shared by the superclass.
gchar *`bus_name`; | A D-Bus well-known bus name, owned by the connection manager process and associated with this connection. Set by tp_base_connection_register; should be considered read-only by subclasses.
gchar *`object_path`; | The object-path of this connection. Set by tp_base_connection_register; should be considered read-only by subclasses.
TpConnectionStatus `status`; | Connection status - may either be a valid TpConnectionStatus or TP_INTERNAL_CONNECTION_STATUS_NEW. Should be considered read-only by subclasses: use `tp_base_connection_change_status()` to set it.

TpHandle `self_handle`;

The handle of type `TP_HANDLE_TYPE_CONTACT` representing the local user. Must be set nonzero by the subclass before moving to state CONNECTED. Since 0.7.15, setting this property directly is deprecated, in favour of `tp_base_connection_set_self_handle()`; if this property is set directly, the connection must ensure it holds a reference to the handle. Changing this property directly having moved to state CONNECTED is very strongly discouraged, as this will prevent the SelfHandleChanged signal being emitted.

### TpBaseConnectionClass

    typedef struct {
        GObjectClass parent_class;

        TpBaseConnectionCreateHandleReposImpl create_handle_repos;

        TpBaseConnectionCreateChannelFactoriesImpl create_channel_factories;

        TpBaseConnectionGetUniqueConnectionNameImpl get_unique_connection_name;

        TpBaseConnectionProc connecting;
        TpBaseConnectionProc connected;
        TpBaseConnectionProc disconnected;

        TpBaseConnectionProc shut_down;

        TpBaseConnectionStartConnectingImpl start_connecting;

        const gchar **interfaces_always_present;

        TpBaseConnectionCreateChannelManagersImpl create_channel_managers;
    } TpBaseConnectionClass;

The class of a TpBaseConnection. Many members are virtual methods etc. to be filled in in the subclass' class_init function.

In addition to the fields documented here, there are three gpointer fields which must currently be `NULL` (a meaning may be defined for these in a future version of telepathy-glib), and a pointer to opaque private data.

GObjectClass `parent_class`; | The superclass' structure
TpBaseConnectionCreateHandleReposImpl `create_handle_repos`; | Fill in suitable handle repositories in the given array for all those handle types this Connection supports. Must be set by subclasses to a non-`NULL` value; the function must create at least a CONTACT handle repository (failing to do so will cause a crash).
TpBaseConnectionCreateChannelFactoriesImpl `create_channel_factories`; | Create an array of channel factories for this Connection. At least one of this or `create_channel_managers` must be set by subclasses to a non-`NULL` value; in new code, setting this to `NULL` and using channel managers exclusively is recommended.
TpBaseConnectionGetUniqueConnectionNameImpl `get_unique_connection_name`; | Construct a unique name for this connection (for example using the protocol's format for usernames). If `NULL` (the default), a unique name will be generated. Subclasses should usually override this to get more obvious names, to aid debugging and prevent multiple connections to the same account.
TpBaseConnectionProc `connecting`; | If set by subclasses, will be called just after the state changes to CONNECTING. May be `NULL` if nothing special needs to happen.
TpBaseConnectionProc `connected`; | If set by subclasses, will be called just after the state changes to CONNECTED. May be `NULL` if nothing special needs to happen.
TpBaseConnectionProc `disconnected`; | If set by subclasses, will be called just after the state changes to DISCONNECTED. May be `NULL` if nothing special needs to happen.
TpBaseConnectionProc `shut_down`; | Called after `disconnected()` is called, to clean up the connection. Must start the shutdown process for the underlying network connection, and arrange for `tp_base_connection_finish_shutdown()` to be called after the underlying connection has been closed. May not be left as `NULL`.
TpBaseConnectionStartConnectingImpl `start_connecting`; | Asynchronously start connecting - called to implement the Connect D-Bus method. See TpBaseConnectionStartConnectingImpl for details. May not be left as `NULL`.
const gchar **`interfaces_always_present`; | A strv of extra D-Bus interfaces which are always implemented by instances of this class, which may be filled in by subclasses. The default is to list no additional interfaces. Individual instances may detect which additional interfaces they support and signal them before going to state CONNECTED by calling `tp_base_connection_add_interfaces()`.
TpBaseConnectionCreateChannelManagersImpl `create_channel_managers`; | Create an array of channel managers for this Connection. At least one of this or `create_channel_factories` must be set by subclasses to a non-`NULL` value. Since: 0.7.15

### TpBaseConnectionCreateChannelFactoriesImpl ()

    GPtrArray *         (*TpBaseConnectionCreateChannelFactoriesImpl)
                                                            (TpBaseConnection *self);

Signature of an implementation of the create_channel_factories method of TpBaseConnection.

`self` : | The implementation, a subclass of TpBaseConnection
Returns : | a GPtrArray of objects implementing TpChannelFactoryIface which, between them, implement all channel types this Connection supports.

### TpBaseConnectionCreateChannelManagersImpl ()

    GPtrArray *         (*TpBaseConnectionCreateChannelManagersImpl)
                                                            (TpBaseConnection *self);

Signature of an implementation of the create_channel_managers method of TpBaseConnection.

`self` : | The implementation, a subclass of TpBaseConnection
Returns : | a GPtrArray of objects implementing TpChannelManager which, between them, implement all channel types this Connection supports.

### TpBaseConnectionCreateHandleReposImpl ()

    void                (*TpBaseConnectionCreateHandleReposImpl)
                                                            (TpBaseConnection *self,
                                                             TpHandleRepoIface *repos[NUM_TP_HANDLE_TYPES]);

Signature of an implementation of the create_handle_repos method of TpBaseConnection.

`self` : | The connection object
`repos` : | An array of pointers to be filled in; the implementation may assume all are initially NULL.

### TpBaseConnectionGetUniqueConnectionNameImpl ()

    gchar *             (*TpBaseConnectionGetUniqueConnectionNameImpl)
                                                            (TpBaseConnection *self);

Signature of the `get_unique_connection_name` virtual method on TpBaseConnection.

`self` : | The implementation, a subclass of TpBaseConnection
Returns : | a name for this connection which will be unique within this connection manager process, as a string which the caller must free with g_free.

### TpBaseConnectionProc ()

    void                (*TpBaseConnectionProc)             (TpBaseConnection *self);

Signature of a virtual method on TpBaseConnection that takes no additional parameters and returns nothing.

`self` : | The connection object

### TpBaseConnectionStartConnectingImpl ()

    gboolean            (*TpBaseConnectionStartConnectingImpl)
                                                            (TpBaseConnection *self,
                                                             GError **error);

Signature of an implementation of the start_connecting method of TpBaseConnection.

On entry, the implementation may assume that it is in state NEW.

If `TRUE` is returned, the Connect D-Bus method succeeds; the implementation must either have already set the status to CONNECTED by calling `tp_base_connection_change_status()`, or have arranged for a status change to either state DISCONNECTED or CONNECTED to be signalled by calling `tp_base_connection_change_status()` at some later time. If the status is still NEW after returning `TRUE`, TpBaseConnection will automatically change it to CONNECTING for reason REQUESTED.

If `FALSE` is returned, the error will be raised from Connect as an exception. If the status is not DISCONNECTED after `FALSE` is returned, TpBaseConnection will automatically change it to DISCONNECTED with a reason appropriate to the error; NetworkError results in NETWORK_ERROR, PermissionDenied results in AUTHENTICATION_FAILED, and all other errors currently result in NONE_SPECIFIED.

All except the simplest connection managers are expected to implement this asynchronously, returning `TRUE` in most cases and changing the status to CONNECTED or DISCONNECTED later.

`self` : | The connection object
`error` : | Set to the error if `FALSE` is returned
Returns : | `FALSE` if failure has already occurred, else `TRUE`.

### tp_base_connection_register ()

    gboolean            tp_base_connection_register         (TpBaseConnection *self,
                                                             const gchar *cm_name,
                                                             gchar **bus_name,
                                                             gchar **object_path,
                                                             GError **error);

Make the connection object appear on the bus, returning the bus name and object path used. If `TRUE` is returned, the connection owns the bus name, and will release it when destroyed.

`self` : | A connection
`cm_name` : | The name of the connection manager in the Telepathy protocol
`bus_name` : | Used to return the bus name corresponding to the connection if `TRUE` is returned; must not be `NULL`. To be freed by the caller.
`object_path` : | Used to return the object path of the connection if `TRUE` is returned; must not be `NULL`. To be freed by the caller.
`error` : | Used to return an error if `FALSE` is returned; may be `NULL`
Returns : | `TRUE` on success, `FALSE` on error.

### tp_base_connection_get_handles ()

    TpHandleRepoIface * tp_base_connection_get_handles      (TpBaseConnection *self,
                                                             TpHandleType handle_type);

`self` : | A connection
`handle_type` : | The handle type
Returns : | the handle repository corresponding to the given handle type, or NULL if it's unsupported or invalid.

### tp_base_connection_get_self_handle ()

    TpHandle            tp_base_connection_get_self_handle  (TpBaseConnection *self);

Returns the "self-handle" property, which is guaranteed not to be 0 once the connection has moved to the CONNECTED state.

`self` : | A connection
Returns : | the current self handle of the connection.

Since 0.7.15

### tp_base_connection_set_self_handle ()

    void                tp_base_connection_set_self_handle  (TpBaseConnection *self,
                                                             TpHandle self_handle);

Sets the "self-handle" property. self_handle may not be 0 once the connection has moved to the CONNECTED state.

`self` : | A connection
`self_handle` : | The new self handle for the connection.

Since 0.7.15

### tp_base_connection_change_status ()

    void                tp_base_connection_change_status    (TpBaseConnection *self,
                                                             TpConnectionStatus status,
                                                             TpConnectionStatusReason reason);

Change the status of the connection. The allowed state transitions are:

- NEW -> CONNECTING
- CONNECTING -> CONNECTED
- NEW -> CONNECTED (equivalent to both of the above one after the other - see below)
- (anything except DISCONNECTED) -> DISCONNECTED

Before the transition to CONNECTED, the implementation must have discovered the handle for the local user, obtained a reference to that handle and stored it in the `self_handle` member of TpBaseConnection.

Changing from NEW to CONNECTED is implemented by doing the transition from NEW to CONNECTING, followed by the transition from CONNECTING to CONNECTED; it's exactly equivalent to calling tp_base_connection_change_status for those two transitions one after the other.

Any other valid transition does the following, in this order:

- Update the `status` member of TpBaseConnection
- If the new state is DISCONNECTED, call the close_all_channels callback on all channel factories
- If the new state is DISCONNECTED, unref the `self_handle`, if any, and set it to 0
- Emit the D-Bus StatusChanged signal
- Call the subclass' status change callback
- Call the channel factories' status change callbacks
- If the new state is DISCONNECTED, call the subclass' `shut_down` callback

`self` : | The connection
`status` : | The new status
`reason` : | The reason for the status change

### tp_base_connection_disconnect_with_dbus_error ()

    void                tp_base_connection_disconnect_with_dbus_error
                                                            (TpBaseConnection *self,
                                                             const gchar *error_name,
                                                             GHashTable *details,
                                                             TpConnectionStatusReason reason);

Change the status of the connection to `TP_CONNECTION_STATUS_DISCONNECTED`, as if by a call to `tp_base_connection_change_status()`. Before doing so, emit the ConnectionError D-Bus signal to give more details of the error.

`details` may contain, among other entries, the well-known key "debug-message", whose value should have type G_TYPE_STRING.

`self` : | The connection
`error_name` : | The D-Bus error with which the connection changed status to Disconnected
`details` : | Further details of the error, as a hash table where the keys are strings as defined in the Telepathy specification, and the values are GValues. `NULL` is allowed, and treated as empty.
`reason` : | The reason code to use in the StatusChanged signal (a less specific, non-extensible version of `error_name`)

Since 0.7.24

### tp_base_connection_finish_shutdown ()

    void                tp_base_connection_finish_shutdown  (TpBaseConnection *self);

Tell the connection manager that this Connection has been disconnected, has emitted StatusChanged and is ready to be removed from D-Bus.

`self` : | The connection

### tp_base_connection_add_interfaces ()

    void                tp_base_connection_add_interfaces   (TpBaseConnection *self,
                                                             const gchar **interfaces);

Add some interfaces to the list supported by this Connection. If you're going to call this function at all, you must do so before moving to state CONNECTED (or DISCONNECTED); if you don't call it, only the set of interfaces always present (`interfaces_always_present` in TpBaseConnectionClass) will be supported.

`self` : | A TpBaseConnection in state TP_INTERNAL_CONNECTION_STATUS_NEW or TP_CONNECTION_STATUS_CONNECTING
`interfaces` : | A `NULL`-terminated array of D-Bus interface names, which must remain valid at least until the connection enters state TP_CONNECTION_STATUS_DISCONNECTED (in practice, you should either use static strings, or use strdup'd strings and free them in the dispose callback).

### tp_base_connection_dbus_request_handles ()

    void                tp_base_connection_dbus_request_handles
                                                            (TpSvcConnection *iface,
                                                             guint handle_type,
                                                             const gchar **names,
                                                             DBusGMethodInvocation *context);

Implements D-Bus method RequestHandles on interface org.freedesktop.Telepathy.Connection. Exported so subclasses can use it as a basis for their own implementations (for instance, at the time of writing Gabble's GabbleConnection does its own processing for room handles, in order to validate them asynchronously, but delegates to this implementation for all other types).

`iface` : | A pointer to TpBaseConnection, cast to a pointer to TpSvcConnection
`handle_type` : | The handle type (TpHandleType) as a guint
`names` : | A strv of handle names
`context` : | The dbus-glib method invocation context

### TP_BASE_CONNECTION_ERROR_IF_NOT_CONNECTED()

    #define             TP_BASE_CONNECTION_ERROR_IF_NOT_CONNECTED(conn, context)

If `conn` is not in state TP_CONNECTION_STATUS_CONNECTED, complete the D-Bus method invocation `context` by raising the Telepathy error TP_ERROR_DISCONNECTED, and return from the current function (which must be void). For use in D-Bus method implementations.

`conn` : | A TpBaseConnection
`context` : | A DBusGMethodInvocation

### tp_base_connection_register_with_contacts_mixin ()

    void                tp_base_connection_register_with_contacts_mixin
                                                            (TpBaseConnection *self);

Register the Connection interface with the Contacts interface to make it inspectable. The Contacts mixin should be initialized before this function is called

`self` : | An instance of the TpBaseConnections that uses the Contacts mixin

### TpChannelManagerIter

    typedef struct {
    } TpChannelManagerIter;

An iterator over the TpChannelManager objects known to a TpBaseConnection. It has no public fields.

Since 0.7.15

### tp_base_connection_channel_manager_iter_init ()

    void                tp_base_connection_channel_manager_iter_init
                                                            (TpChannelManagerIter *iter,
                                                             TpBaseConnection *self);

Initializes an iterator over the TpChannelManager objects known to `self`. It is intended to be used as followed:

    TpChannelManagerIter iter;
    TpChannelManager *manager;

    tp_base_connection_channel_manager_iter_init (&iter, base_conn);
    while (tp_base_connection_channel_manager_iter_next (&iter, &manager))
      {
        ...do something with manager...
      }

`iter` : | an uninitialized TpChannelManagerIter
`self` : | a connection

Since 0.7.15

### tp_base_connection_channel_manager_iter_next ()

    gboolean            tp_base_connection_channel_manager_iter_next
                                                            (TpChannelManagerIter *iter,
                                                             TpChannelManager **manager_out);

Advances `iter`, and retrieves the TpChannelManager it now points to. If there are no more channel managers, `manager_out` is not set and `FALSE` is returned.

`iter` : | an initialized TpChannelManagerIter
`manager_out` : | a location to store the channel manager, or `NULL`.
Returns : | `FALSE` if there are no more channel managers; else `TRUE`.

Since 0.7.15

## Property Details

### The `"protocol"` property

      "protocol"                 gchar*                : Read / Write / Construct Only

Identifier used in the Telepathy protocol when this connection's protocol name is required.

Default value: NULL

### The `"self-handle"` property

      "self-handle"              guint                 : Read / Write

The handle of type `TP_HANDLE_TYPE_CONTACT` representing the local user. Must be set nonzero by the subclass before moving to state CONNECTED.

Default value: 0

Since 0.7.15

## Signal Details

### The `"shutdown-finished"` signal

    void                user_function                      (TpBaseConnection *arg0,
                                                            gpointer          user_data)      : Run Last / Has Details

Emitted by `tp_base_connection_finish_shutdown()` when the underlying network connection has been closed; TpBaseConnectionManager listens for this signal and removes connections from its table of active connections when it is received.

`user_data` : | user data set when the signal handler was connected.

## See Also

#TpBaseConnectionManager, TpSvcConnection