Browser polling for messages

When the browser makes a poll to get the latest messages, our server should return the messages in a JSON format. To achieve this, we'll need to create a new HTTP endpoint that returns the messages as JSON, without using the Jinja2 templating. We will first construct a new helper function to create a JSON response, setting the correct headers.

Outside of our WebServer, create the following function:

def create_json_response(content): 
    headers = {'Content-Type': 'application/json'} 
    json_data = json.dumps(content) 
    return Response(json_data, status=200, headers=headers) 

This is similar to our create_html_response from earlier, but here it sets the Content-Type to 'application/json' and converts our data into a valid JSON object.

Now, within the WebServer, create the following HTTP entrypoint:

@http('GET', '/messages') 
def get_messages(self, request): 
    messages = self.message_service.get_all_messages() 
    return create_json_response(messages) 

This...