:orphan:

.. _chatroom.py:

chatroom.py
===========

.. code-block:: py
    :linenos:


    """
    Simple chat web app in less than 80 lines.
    
    This app might be running at the demo server: http://flexx1.zoof.io
    """
    
    from flexx import app, ui, event
    
    
    class Relay(event.HasEvents):
        """ Global object to relay messages to all participants.
        """
        @event.emitter
        def new_message(self, msg):
            return dict(msg=msg + '<br />')
    
    
    class MessageBox(ui.Label):
        CSS = """
        .flx-MessageBox {
            overflow-y:scroll;
            background: #e8e8e8;
            border: 1px solid #444;
            margin: 3px;
        }
        """
    
    
    # Create global relay
    relay = Relay()
    
    
    class ChatRoom(ui.Widget):
        """ Despite the name, this represents one connection to the chat room.
        """
        
        def init(self):
            with ui.HBox():
                ui.Widget(flex=1)
                with ui.VBox():
                    self.name = ui.LineEdit(placeholder_text='your name')
                    self.people = ui.Label(flex=1, base_size=(250, 0))
                with ui.VBox():
                    self.messages = MessageBox(flex=1)
                    with ui.HBox():
                        self.message = ui.LineEdit(flex=1, placeholder_text='enter message')
                        self.ok = ui.Button(text='Send')
                ui.Widget(flex=1)
            
            self._update_participants()
        
        @relay.connect('new_message')  # note that we connect to relay
        def _push_info(self, *events):
            for ev in events:
                self.emit('new_message', ev)
        
        def _update_participants(self):
            if not self.session.status:
                return  # and dont't invoke a new call
            sessions = app.manager.get_connections(self.session.app_name)
            names = [p._chatroom_name for p in sessions]  # _chatroom_name is what we set
            del sessions
            text = '<br />%i persons in this chat:<br /><br />' % len(names)
            text += '<br />'.join([name or 'anonymous' for name in sorted(names)])
            self.people.text = text
            app.call_later(3, self._update_participants)
        
        @event.connect('ok.mouse_down', 'message.submit')
        def _send_message(self, *events):
            text = self.message.text
            if text:
                name = self.name.text or 'anonymous'
                relay.new_message('<i>%s</i>: %s' % (name, text))
                self.message.text = ''
        
        @event.connect('name.text')
        def _name_changed(self, *events):
            self.session._chatroom_name = self.name.text
        
        class JS:
            
            @event.connect('!new_message')
            def _update_total_text(self, *events):
                self.messages.text += ''.join([ev.msg for ev in events])
    
    
    
    if __name__ == '__main__':
        a = app.App(ChatRoom, title='Flexx chatroom demo')
        a.serve()
        # a.launch()  # for use during development
        app.start()