:orphan:

.. _flexx_in_thread.py:

flexx_in_thread.py
==================

.. code-block:: py
    :linenos:


    """
    Example showing running Flexx' event loop in another thread.
    This is not a recommended use in general.
    
    Most parts of Flexx are not thread-save. E.g. setting properties
    should generally only be done from a single thread. Event handlers
    are *always* called from the same thread that runs the event loop
    (unless manually called).
    
    The app.create_server() is used to (re)create the server object. It is
    important that the used IOLoop is local to the thread. This can be
    accomplished by calling create_server() and start() from the same
    thread, or using ``new_loop=True`` (as is done here).
    """
    
    import time
    import threading
    
    from flexx import app, event
    
    
    class MyModel1(event.HasEvents):
        @event.prop
        def foo(self, v=0):
            return v
        
        @event.connect('foo')
        def on_foo(self, *events):
            for ev in events:
                print('foo changed to', ev.new_value)
    
    # Create model in main thread
    model = MyModel1()
    
    # Start server in its own thread
    app.create_server(new_loop=True)
    t = threading.Thread(target=app.start)
    t.start()
    
    # Manipulate model from main thread (the model's on_foo() gets called from other thread)
    for i in range(5, 9):
        time.sleep(1)
        model.foo = i
    
    # Stop event loop (this is thread-safe) and wait for thread to end
    app.stop()
    t.join()