SCCD/examples/chatclient/model_chatclient.xml

<single_instance_cd>
  <delta>1 ms</delta>

  <statechart>
    <datamodel>
      import sccd.action_lang.lib.utils;
      
      import lib.network_client;
      import lib.ui;
      import lib.utils;

      # Statechart's variables
      curr_server = 0;
      room_number = 0;
      reconnected = False;
    </datamodel>

    <inport name="network">
      <event name="connected"/>
      <event name="disconnected"/>
      <event name="joined"/>
      <event name="left"/>
      <event name="receive_message"/>
      <event name="alive"/>
    </inport>

    <inport name="ui">
      <event name="input"/>
    </inport>

    <outport name="network">
      <event name="connect"/>
      <event name="disconnect"/>
      <event name="join"/>
      <event name="leave"/>
      <event name="send_message"/>
      <event name="poll"/>
    </outport>

    <root>
      <parallel id="p">
        <!-- main orthogonal region -->
        <state id="main" initial="disconnected">
          <state id="disconnected" initial="initial">
            <onentry>
              <code> input_command(); </code>
            </onentry>
            <state id="initial">
              <transition after="100 ms" target="../trying_connect">
                <code> add_message("trying to connect to server " + get_server(curr_server), "info"); </code>
                <raise event="connect">
                  <param expr="get_server(curr_server)"/>
                </raise>
              </transition>
            </state>
            <state id="trying_connect">
              <transition event="connected" target="/p/main/connected">
                <code> add_message("connected to server " + get_server(curr_server), "info"); </code>
              </transition>
              <transition after="5 s" target="../initial">
                <code>
                  add_message("unable to connect to server " + get_server(curr_server), "info");
                  curr_server = (curr_server + 1) % get_nr_of_servers();
                </code>
              </transition>
            </state>
          </state>

          <state id="reconnecting" initial="initial">
            <onentry>
              <code> input_command(); </code>
            </onentry>
            <state id="initial">
              <transition after="100 ms" target="../trying_connect">
                <code> add_message("trying to connect to server " + get_server(curr_server), "info"); </code>
                <raise event="connect">
                  <param expr="get_server(curr_server)"/>
                </raise>
              </transition>
            </state>
            <state id="trying_connect">
              <transition event="connected" target="/p/main/connected/joining">
                <code> add_message("connected to server" + get_server(curr_server), "info"); </code>
              </transition>
              <transition after="5 s" target="../initial">
                  <code> add_message("unable to connect to server " + get_server(curr_server), "info"); </code>
              </transition>
            </state>

            <!-- ?? -->
          </state>

          <state id="connected" initial="connected">
            <transition event="do_disconnect" target="../reconnecting">
              <code> add_message("disconnected", "info"); </code>
            </transition>

            <state id="leaving">
              <transition event="left" target="../connected">
                <code> add_message("left room", "info"); </code>
              </transition>
            </state>

            <state id="connected">
              <transition event="input(char: str)" cond='char == "j"' target="../getting_roomnumber">
                <code> input_join(); </code>
              </transition>
            </state>

            <state id="getting_roomnumber">
              <transition event="input(char: str)" cond="is_backspace(char)" target=".">
                <code> remove_last_in_buffer(); </code>
              </transition>
              <transition event="input(char: str)" cond="is_enter(char)" target="../joining">
                <code>
                  room_number = stoi(get_buffer());
                  clear_input();
                  input_command();
                </code>
              </transition>
              <transition event="input(char: str)" cond="is_numerical(char)" target=".">
                <code> append_to_buffer(char); </code>
              </transition>
              <transition event="input(char: str)" cond="not is_numerical(char)" target=".">
                <code> add_message("only numerical input allowed!", "warning"); </code>
              </transition>
            </state>

            <state id="joining">
              <onentry>
                <raise event="join">
                  <param expr="room_number"/>
                </raise>
              </onentry>
              <onexit>
              </onexit>

              <transition event="joined" target="../joined/H">
                <code> add_message("joined room " + int_to_str(room_number), "info"); </code>
              </transition>
            </state>

            <state id="joined" initial="initial">
              <state id="initial">
                <!--<onentry>
                  <code> input_command(); </code>
                </onentry>-->

                <transition event="input(char: str)" cond='char == "m"' target="../entering_message"/>
                <transition event="input(char: str)" cond='char == "l"' target="../../leaving">
                  <raise event="leave"/>
                  <code> input_command(); </code>
                </transition>
              </state>

              <state id="entering_message">
                <onentry>
                  <code> input_msg(); </code>
                </onentry>
                <!-- explicit (document order) priority used here: -->
                <transition event="input(char: str)" cond="is_backspace(char)" target=".">
                  <code> remove_last_in_buffer(); </code>
                </transition>
                <transition event="input(char: str)" cond="is_enter(char)" target="../initial">
                  <raise event="send_message">
                    <param expr="get_buffer()"/>
                  </raise>
                  <code>
                    add_message(get_buffer(), "local_message");
                    clear_input();
                    input_command();
                  </code>
                </transition>
                <transition event="input(char: str)" target=".">
                  <code> append_to_buffer(char); </code>
                </transition>
              </state>

              <history id="H" type="shallow"/>
            </state>
          </state>
        </state>

        <!-- polling orthogonal region -->
        <state id="polling" initial="initial">
          <state id="initial">
            <transition event="connected" target="../polling"/>
          </state>
          <state id="polling">
            <transition after="1 s" target="../expecting_answer">
              <raise event="poll"/>
              <!-- <code> print("sent POLL"); </code> -->
            </transition>
          </state>
          <state id="expecting_answer">
            <transition event="alive" target="../polling">
              <!-- <code> print("got ALIVE"); </code> -->
            </transition>
            <transition after="2 s" target="../initial">
              <raise event="do_disconnect"/>
              <code> print("polling timeout... disconnect"); </code>
            </transition>
          </state>
        </state>

        <!-- listening orthogonal region -->
        <state id="listening">
          <state id="l">
            <transition event="receive_message(msg:str)" target=".">
              <code> add_message(msg, "remote_message"); </code>
            </transition>
          </state>
        </state>
      </parallel>
    </root>

  </statechart>
</single_instance_cd>