path: root/spec/Channel_Request.xml

<?xml version="1.0" ?>
<node name="/Channel_Request"
  xmlns:tp="http://telepathy.freedesktop.org/wiki/DbusSpec#extensions-v0">

  <tp:copyright>Copyright © 2008–2011 Collabora Ltd.</tp:copyright>
  <tp:copyright>Copyright © 2008–2009 Nokia Corporation</tp:copyright>
  <tp:license xmlns="http://www.w3.org/1999/xhtml">
    <p>This library is free software; you can redistribute it and/or
      modify it under the terms of the GNU Lesser General Public
      License as published by the Free Software Foundation; either
      version 2.1 of the License, or (at your option) any later version.</p>

    <p>This library is distributed in the hope that it will be useful,
      but WITHOUT ANY WARRANTY; without even the implied warranty of
      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      Lesser General Public License for more details.</p>

    <p>You should have received a copy of the GNU Lesser General Public
      License along with this library; if not, write to the Free Software
      Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
      MA 02110-1301, USA.</p>
  </tp:license>

  <interface name="im.telepathy.v1.ChannelRequest">
    <tp:added version="0.17.26">(as a stable interface)</tp:added>

    <tp:docstring xmlns="http://www.w3.org/1999/xhtml">
      <p>A channel request is an object in the <tp:dbus-ref
        namespace='imt1'>ChannelDispatcher</tp:dbus-ref> representing
        an ongoing request for some channels to be created or found. They are
        created by methods such as <tp:dbus-ref
        namespace='imt1.ChannelDispatcher'>CreateChannel</tp:dbus-ref>. There
        can be any number of ChannelRequest objects at the same time.</p>

      <p>Its well-known bus name is the same as that of the ChannelDispatcher,
        <code>"im.telepathy.v1.ChannelDispatcher"</code>.</p>

      <tp:rationale>
        <p>See
          <tp:dbus-ref namespace="im.telepathy.v1">ChannelDispatcher.CreateChannel</tp:dbus-ref>
          for rationale for ChannelRequest being a separate object.</p>
      </tp:rationale>

      <p>A channel request can be cancelled by any client (not just the one
        that requested it). This means that the ChannelDispatcher will
        <tp:dbus-ref namespace="im.telepathy.v1.Channel">Close</tp:dbus-ref>
        the resulting channel, or refrain from requesting it at all, rather
        than dispatching it to a handler.</p>
    </tp:docstring>

    <property name="Account" tp:name-for-bindings="Account"
      type="o" access="read" tp:immutable="yes">
      <tp:docstring>
        The <tp:dbus-ref
          namespace="im.telepathy.v1">Account</tp:dbus-ref>
        on which this request was made. This property cannot change.
      </tp:docstring>
    </property>

    <property name="UserActionTime" tp:name-for-bindings="User_Action_Time"
      type="x" tp:type="User_Action_Timestamp" access="read"
      tp:immutable="yes">
      <tp:docstring xmlns="http://www.w3.org/1999/xhtml">
        <p>The time at which user action occurred, or 0 if this channel
          request is for some reason not involving user action.</p>

        <p>This property is set when the channel request is created,
          and can never change.</p>
      </tp:docstring>
    </property>

    <property name="PreferredHandler" tp:name-for-bindings="Preferred_Handler"
      type="s" tp:type="DBus_Well_Known_Name" access="read" tp:immutable="yes">
      <tp:docstring xmlns="http://www.w3.org/1999/xhtml">
          <p>Either the well-known bus name (starting with
            <code>im.telepathy.v1.Client.</code>)
            of the preferred handler for this
            channel, or an empty string to indicate that any handler would be
            acceptable.</p>

        <p>This property is set when the channel request is created,
          and can never change.</p>
      </tp:docstring>
    </property>

    <property name="Requests" tp:name-for-bindings="Requests" type="aa{sv}"
      tp:type="Qualified_Property_Value_Map[]"
      access="read" tp:immutable="yes">
      <tp:docstring xmlns="http://www.w3.org/1999/xhtml">
        <p>An array of dictionaries containing desirable properties for
          the channel or channels to be created.</p>

        <tp:rationale>
          <p>This is an array so that we could add a CreateChannels method in
            future without redefining the API of ChannelRequest.</p>
        </tp:rationale>

        <p>This property is set when the channel request is created,
          and can never change.</p>
      </tp:docstring>
    </property>

    <property name="Interfaces" tp:name-for-bindings="Interfaces"
      type="as" access="read" tp:type="DBus_Interface[]" tp:immutable="yes">
      <tp:docstring>
        A list of the extra interfaces provided by this channel request.
        This property cannot change.
      </tp:docstring>
    </property>

    <method name="Proceed" tp:name-for-bindings="Proceed">
      <tp:docstring xmlns="http://www.w3.org/1999/xhtml">
        <p>Proceed with the channel request.</p>

        <tp:rationale>
          <p>The client that created this object calls this method
            when it has connected signal handlers for
            <tp:member-ref>Succeeded</tp:member-ref> and
            <tp:member-ref>Failed</tp:member-ref>.</p>
        </tp:rationale>

        <p>Clients other than the client which created the ChannelRequest
          MUST NOT call this method.</p>

        <p>This method SHOULD return immediately; on success, the request
          might still fail, but this will be indicated asynchronously
          by the <tp:member-ref>Failed</tp:member-ref> signal.</p>

        <p>Proceed cannot fail, unless clients have got the life-cycle
          of a ChannelRequest seriously wrong (e.g. a client calls this
          method twice, or a client that did not create the ChannelRequest
          calls this method). If it fails, clients SHOULD assume that the
          whole ChannelRequest has become useless.</p>
      </tp:docstring>

      <tp:possible-errors>
        <tp:error name="im.telepathy.v1.Error.NotAvailable">
          <tp:docstring>
            This method has already been called, so it is no longer
            available. Stop calling it.
          </tp:docstring>
        </tp:error>
      </tp:possible-errors>
    </method>

    <method name="Cancel" tp:name-for-bindings="Cancel">
      <tp:docstring xmlns="http://www.w3.org/1999/xhtml">
        <p>Cancel the channel request. The precise effect depends on the
          current progress of the request.</p>

        <p>If the connection manager has not already been asked to create
          a channel, then <tp:member-ref>Failed</tp:member-ref> is emitted
          immediately, and the channel request is removed.</p>

        <p>If the connection manager has already been asked to create a
          channel but has not produced one yet (e.g. if <tp:dbus-ref
            namespace="im.telepathy.v1">Connection.Interface.Requests.CreateChannel</tp:dbus-ref>
          has been called, but has not yet returned), then the
          ChannelDispatcher will remember that the request has been cancelled.
          When the channel appears, it will be closed (if it was newly
          created and can be closed), and will not be dispatched to a
          handler.</p>

        <p>If the connection manager has already returned a channel, but the
          channel has not yet been dispatched to a handler
          then the channel dispatcher will not dispatch that
          channel to a handler. If the channel was newly created for this
          request, the channel dispatcher will close it with <tp:dbus-ref
          namespace="im.telepathy.v1.Channel">Close</tp:dbus-ref>;
          otherwise, the channel dispatcher will ignore it. In either case,
          <tp:member-ref>Failed</tp:member-ref> will be emitted when processing
          has been completed.</p>

        <p>If <tp:member-ref>Failed</tp:member-ref> is emitted in response to
          this method, the error SHOULD be
          <code>im.telepathy.v1.Error.Cancelled</code>.</p>

        <p>If the channel has already been dispatched to a handler, then
          it's too late to call this method, and the channel request will
          no longer exist.</p>
      </tp:docstring>
    </method>

    <signal name="Failed" tp:name-for-bindings="Failed">
      <tp:docstring xmlns="http://www.w3.org/1999/xhtml">
        <p>The channel request has failed. It is no longer present,
          and further methods must not be called on it.</p>
      </tp:docstring>

      <arg name="Error" type="s" tp:type="DBus_Error_Name">
        <tp:docstring xmlns="http://www.w3.org/1999/xhtml">
          <p>The name of a D-Bus error. This can come from various sources,
            including the error raised by <tp:dbus-ref
              namespace="im.telepathy.v1.Connection.Interface.Requests">CreateChannel</tp:dbus-ref>,
            or an error generated
            to represent failure to establish the <tp:dbus-ref
              namespace="im.telepathy.v1">Connection</tp:dbus-ref>.</p>
        </tp:docstring>
      </arg>

      <arg name="Message" type="s">
        <tp:docstring>
          If the first argument of the D-Bus error message was a string,
          that string. Otherwise, an empty string.
        </tp:docstring>
      </arg>
    </signal>

    <property name="Hints" tp:name-for-bindings="Hints"
      type="a{sv}" access="read" tp:immutable="yes">
      <tp:added version="0.21.5"/>
      <tp:docstring xmlns="http://www.w3.org/1999/xhtml">
        <p>A dictionary of metadata provided by the channel
          requester, which the handler and other clients MAY choose to
          interpret.  Clients MAY
          choose to use platform-specific keys for their own purposes, but MUST
          ignore unknown keys and MUST cope with expected keys being
          missing. Clients SHOULD namespace hint names by having them
          start with a reversed domain name, in the same way as D-Bus
          interface names.</p>

        <tp:rationale>This property might be used to pass a contact ID for a
          telephone number shared between two contacts from the address book to
          the call UI, so that if you try to call “Mum”, the call UI knows this
          rather than having to guess or show “Calling Mum or Dad”. The format
          of these contact IDs would be platform-specific, so we leave the
          definition of the dictionary entry up to the platform in question.
          But third-party channel requesters might not include the contact ID,
          so the call UI has to be able to deal with it not being
          there.</tp:rationale>

        <p>The channel dispatcher does not currently interpret any of these
          hints: they are solely for communication between cooperating
          clients. If hints that do affect the channel dispatcher are added in
          future, their names will start with an appropriate reversed domain
          name (e.g. <code>im.telepathy.v1</code> for hints defined
          by this specification, or an appropriate vendor name for third-party
          plugins).</p>

        <p>This property may be set when the channel request is created, and
          can never change. Since it is immutable, it SHOULD be included in the
          dictionary of properties passed to <tp:dbus-ref
          namespace="imt1.Client.Interface.Requests">AddRequest</tp:dbus-ref>
          by the <tp:dbus-ref
          namespace="im.telepathy.v1">ChannelDispatcher</tp:dbus-ref>.</p>
        <p>The following standardised hints are defined:</p>

        <dl>
          <dt>im.telepathy.v1.ChannelRequest.DelegateToPreferredHandler - b</dt>
          <dd>If present and True the client currently handling the channel
            SHOULD pass the channel to the
            <tp:member-ref>PreferredHandler</tp:member-ref> using
            <tp:dbus-ref namespace="imt1.ChannelDispatcher">DelegateChannels</tp:dbus-ref>.

            <tp:rationale>
              This hint allows the user to request a channel in their
              preferred client in a situation where there are two chat
              handlers (for example: requesting a channel in Empathy which is
              currently being handled by gnome-shell).
            </tp:rationale>

            If the channel is currently unhandled, clients SHOULD ignore this
            hint.

            <tp:rationale>
              It is assumed that Mission Control will correctly delegate an
              unhandled channel to the preferred Handler. This allows
              requesting clients to always include this hint in their channel
              request.
            </tp:rationale>

            The Handler should check each
            <tp:dbus-ref namespace="imt1">ChannelRequest</tp:dbus-ref>
            of the Requests_Satisfied parameter of
            <tp:dbus-ref namespace="imt1.Client.Handler">HandleChannel</tp:dbus-ref>
            for the hint. The first request containing the hint SHOULD be used
            and all further hints SHOULD be ignored.

            <tp:rationale>
              This covers the very unlikely case where
              <tp:dbus-ref namespace="imt1.Client.Handler">HandleChannel</tp:dbus-ref>
              satisfies two separate requests which have different
              <tp:member-ref>PreferredHandler</tp:member-ref>s.
            </tp:rationale>
          </dd>
        </dl>

      </tp:docstring>
    </property>

    <signal name="Succeeded" tp:name-for-bindings="Succeeded">
      <tp:added version="0.21.5"/>
      <tp:docstring xmlns="http://www.w3.org/1999/xhtml">
        <p>The channel request has succeeded. It is no longer present,
          and further methods must not be called on it.</p>

        <p>This signal MUST be emitted before
          the <tp:member-ref>Succeeded</tp:member-ref> signal.</p>
      </tp:docstring>

      <arg name="Connection" type="o">
        <tp:docstring xmlns="http://www.w3.org/1999/xhtml">
          <p>The Connection owning the channel.</p>
        </tp:docstring>
      </arg>

      <arg name="Connection_Properties" type="a{sv}"
        tp:type="Qualified_Property_Value_Map">
        <tp:docstring xmlns="http://www.w3.org/1999/xhtml">
          <p>A subset of the Connection's properties, currently unused.
            This parameter may be used in future.</p>
        </tp:docstring>
      </arg>

      <arg name="Channel" type="o">
        <tp:docstring xmlns="http://www.w3.org/1999/xhtml">
          <p>The channel which has been created.</p>
        </tp:docstring>
      </arg>

      <arg name="Channel_Properties" type="a{sv}"
        tp:type="Qualified_Property_Value_Map">
        <tp:docstring xmlns="http://www.w3.org/1999/xhtml">
          <p>The same immutable properties of the Channel that would appear
            in a <tp:dbus-ref namespace="imt1.Connection.Interface.Requests"
              >NewChannel</tp:dbus-ref> signal.</p>
        </tp:docstring>
      </arg>

    </signal>

  </interface>
</node>
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