How to receive array of objects as parameters in Python Flask passed as HTTP request using AJAX?

Question

My ajax call looks like this:

  $.ajax({
    url: "/doSomeCoolThingOnServer",
    type: "POST",
    async: false,
    data: {
      simple_string: "Variable sent from client side",
      array_of_strings: ["John", "George"],
      array_of_objects: [
        { city: "Shanghai", population: 1000 },
        { city: "Budapest", population: 2501 }
      ]
    },
    success: function(response) {
      console.log("===== SUCCESS =====");
      console.log(response);
    },
    error: function(response) {
      console.log("===== ERROR =====");
      console.log(response);
    }
  });

I am trying to receive the array of objects as an array of dicts on Python, but I am returned with an empty array.

@app.route("/doSomeCoolThingOnServer", methods=['POST'])
def doSomeCoolThingOnServer():
    simple_string = request.form['simple_string']
    array_of_strings = request.form.getlist('array_of_strings[]')
    array_of_objects = request.form.getlist('array_of_objects[]')

    print(simple_string) #returns desired string
    print(array_of_strings) # returns desired array
    print(array_of_objects) # returns empty array

Please advise how to receive array of objects as parameters in Python Flask passed as HTTP POST request using AJAX?

ikkuh · Accepted Answer · 2017-06-14 08:47:38Z

3

You could serialize your objects using JSON.stringify and deserialize then on the server with json.loads. This effectively sends your array of objects as array of strings.

Serialize for ajax call:

array_of_objects: [
    JSON.stringify({ city: "Shanghai", population: 1000 }),
    JSON.stringify({ city: "Budapest", population: 2501 })
]

Deserialize on server:

import json
array_of_objects = request.form.getlist('array_of_objects[]')
print([json.loads(s) for s in array_of_objects])

Another option is to serialize the entire array instead of every array element separately. This sends the array of objects as a single string:

array_of_objects: JSON.stringify([
    { city: "Shanghai", population: 1000 },
    { city: "Budapest", population: 2501 }
])

import json
array_of_objects = request.form['array_of_objects']
print(json.loads(array_of_objects))

edited Jun 14, 2017 at 8:47

answered Jun 14, 2017 at 8:17

ikkuh

4,6233 gold badges28 silver badges42 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

How to receive array of objects as parameters in Python Flask passed as HTTP request using AJAX?

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related