Flask parseError on request

Question

I tried to send a request to my Flask App via JavaScript. My JS code is the following:

$.ajax({
        url: 'localhost:5000/api/login',
        method: 'POST',
        contentType: "application/json; charset=utf-8",
        dataType: "json",
        data: "lel",
        success: function (response) {
            alert("Erfolgreich " + response )
        },
        error: function (jqXHR, exception) {
            alert("code: " + jqXHR.status + "  " + exception.toString());

        }
    });

This is my Flask function for /api/login

@app.route("/api/login", methods=['POST'])
def api_login():
    return "it works"

My JavaScript output over the alert is: code: 200 parsererror The Flask console output is:

XX.XXX.XX.XX - - [28/Apr/2020 15:48:20] "[37mOPTIONS /api/login HTTP/1.1[0m" 200 -
XX.XXX.XX.XX - - [28/Apr/2020 15:48:21] "[37mPOST /api/login HTTP/1.1[0m" 200 -

Why is this happening and how can I fix it?

Answer 1

you need to return a valid json response from flask