how can I use data posted from ajax in flask?

Question

I\'m having trouble getting data POSTed from jquery ajax.

$(\'#clickme\').click( function() {
    var data = save_input(); // data

    data[\'_sid\'] = $sur         


        

Answer 1

As per your example you are not sending a key value pair but rather assigning a JSON string to the jQuery data option. As mentioned in the comments you have to stringify your JSON, create an object with a key (which will be used to access the JSON string from flask) and then assign it to the jQuery data key.

    $.ajax({
            type : "POST",
            url : "{{ url_for('mod.load_ajax') }}",
            data: {json_str: JSON.stringify(data)},
            contentType: 'application/json;charset=UTF-8',
            success: function(result) {
                console.log(result);
            }
        });

    @mod.route('/load_ajax', methods=["GET", "POST"])
    def load_ajax():
        if request.method == "POST":
            # load _sid and _uip from posted JSON and save other data
            # but request.form is empty.
            # >>> request.form
            # ImmutableMultiDict([]) 
            return str(request.form['json_str']
     )

Answer 2

On the flask side, use:

data = request.get_json()

The variable data now has the dictionary you sent using ajax and you can now manipulate it with python

Answer 3

Have you tried remove contentType? You suppose to post data to Flask.

could you try add fake data like

data:{"hello":"world"} inside ajax? just to check if the hello world arrive to request.form

Answer 4

Try

 $.ajax({
    type : "POST",
    url : "{{ url_for('mod.load_ajax') }}",
    data: JSON.stringify(data, null, '\t'),
    contentType: 'application/json;charset=UTF-8',
    success: function(result) {
        console.log(result);
    }
});

Then from the server, you can refer to the variables in data like this :

request.json['foo']

Since the content type is specified as application/json the data is in request.json