:orphan:

.. _errors.py:

errors.py
=========

.. code-block:: py
    :linenos:


    """
    App that can be used to generate errors on the Python and JS side. These
    errors should show tracebacks in the correct manner (and not crash the app
    as in #164).
    
    To test thoroughly, you should probably also set the foo and bar
    properties from the Python and JS console.
    """
    
    from flexx import app, event, ui
    
    
    class Errors(ui.Widget):
        
        def init(self):
            
            with ui.VBox():
                self.b1 = ui.Button(text='Raise error in JS property setter')
                self.b2 = ui.Button(text='Raise error in JS event handler')
                self.b3 = ui.Button(text='Raise error in Python property setter')
                self.b4 = ui.Button(text='Raise error in Python event handler')
                ui.Widget(flex=1)  # spacer
        
        class Both:
            
            @event.prop
            def foo(self, v=1):
                return self.reciprocal(v)
            
            def reciprocal(self, v):
                return 1 / v
            
            def raise_error(self):
                raise RuntimeError('Deliberate error')
        
        class JS:
            
            @event.prop
            def bar(self, v):
                self.raise_error()
            
            # Handlers for four buttons
            
            @event.connect('b1.mouse_click')
            def error_in_JS_prop(self, *events):
                self.bar = 2
            
            @event.connect('b2.mouse_click')
            def error_in_JS_handler(self, *events):
                self.raise_error()
            
            @event.connect('b3.mouse_click')
            def error_in_Py_prop(self, *events):
                self.foo = 0
        
        @event.connect('b4.mouse_click')
        def error_in_Py_handler(self, *events):
            self.raise_error()
    
    
    if __name__ == '__main__':
        m = app.launch(Errors, 'browser')
        app.run()