Post throwing 500 error

Question

I'm writing a small app. Here is the code snippet.

Javascript:

<script type="text/javascript">
function filldata()
{
    var sample = document.getElementById("filter-select").value;
    jQuery.support.cors = true;
    $.post("/test",{"filter_type":sample},function(data,status)
    {
    alert(data);
    });
}
</script>

Flask Code:

@app.route('/test', methods=['POST'])
def test(str):
    return str

It is giving me 500 internal error .
When I run this in debug mode, it is saying:

test() takes exactly one argument(zero given)

Answer 1

Your code:

@app.route('/test',methods=['POST'])
def test(str):
    return str

Expect a variable named str in input. With flask, when defining route the arguments of the function represent the url variables:

# the url have a parameter
@app.route('/user/<id>',methods=['GET'])
    def test(id): # we get it here
        return user.fromId(id)

To retrieve querystring you can use request.args . And to get body request.data or request.json if you are sending json.

from flask import request

@app.route('/test',methods=['POST'])
def test():
    return request.data

Answer 2

You need to parse argument from Flask's request object

from flask import request

@app.route('/test',methods=['POST'])
def test():
    return request.form.get('filter_type')

See quickstart for more info

Answer 3

In your Flask code snippet, you have added an argument, but arguments are only sent if you change the URL to /test/<str:str> . Since it is a POST request, you can access the data by using request.json .