jQuery.ajax returns 400 Bad Request - ajax

Question

This works fine:
jQuery('#my_get_related_keywords').click(function() {
if (jQuery('#my_keyword').val() == '') return false;
jQuery.getJSON("http://boss.yahooapis.com/ysearch/web/v1/"
+jQuery('#my_keyword').val()+"?"
+"appid=myAppID"
+"&lang=en"
+"&format=json"
+"&count=50"
+"&view=keyterms"
+"&callback=?",
function (data) {//do something}
This returns 400 Bad Request (Just a reformulation of the above jQuery using .ajax to support error handling).
jQuery('#my_get_related_keywords').click(function()
{
if (jQuery('#my_keyword').val() == '') return false;
jQuery('#my_loader').show();
jQuery.ajax(
{
url: "http://boss.yahooapis.com/ysearch/web/v1/"
+jQuery('#my_keyword').val()+"?"
+"appid=myAppID"
+"&lang=en"
+"&format=json"
+"&count=50"
+"&view=keyterms"
+"&callback=?",
success: function(data)
{//do something}

Answer 1

I think you just need to add 2 more options (contentType and dataType):
$('#my_get_related_keywords').click(function() {
$.ajax({
type: "POST",
url: "HERE PUT THE PATH OF YOUR SERVICE OR PAGE",
data: '{"HERE YOU CAN PUT DATA TO PASS AT THE SERVICE"}',
contentType: "application/json; charset=utf-8", // this
dataType: "json", // and this
success: function (msg) {
//do something
},
error: function (errormessage) {
//do something else
}
});
}

Answer 2

Add this to your ajax call:
contentType: "application/json; charset=utf-8",
dataType: "json"

Answer 3

Late answer, but I figured it's worth keeping this updated. Expanding on Andrea Turri answer to reflect updated jQuery API and .success/.error deprecated methods.
As of jQuery 1.8.* the preferred way of doing this is to use .done() and .fail(). Jquery Docs
e.g.
$('#my_get_related_keywords').click(function() {
var ajaxRequest = $.ajax({
type: "POST",
url: "HERE PUT THE PATH OF YOUR SERVICE OR PAGE",
data: '{"HERE YOU CAN PUT DATA TO PASS AT THE SERVICE"}',
contentType: "application/json; charset=utf-8",
dataType: "json"});
//When the request successfully finished, execute passed in function
ajaxRequest.done(function(msg){
//do something
});
//When the request failed, execute the passed in function
ajaxRequest.fail(function(jqXHR, status){
//do something else
});
});

Answer 4

Be sure and use 'get' or 'post' consistantly with your $.ajax call for example.
$.ajax({
type: 'get',
must be met with
app.get('/', function(req, res) {
===============
and for post
$.ajax({
type: 'post',
must be met with
app.post('/', function(req, res) {

Answer 5

I was getting the 400 Bad Request error, even after setting:
contentType: "application/json",
dataType: "json"
The issue was with the type of a property passed in the json object, for the data property in the ajax request object.
To figure out the issue, I added an error handler and then logged the error to the console. Console log will clearly show validation errors for the properties if any.
This was my initial code:
var data = {
"TestId": testId,
"PlayerId": parseInt(playerId),
"Result": result
};
var url = document.location.protocol + "//" + document.location.host + "/api/tests"
$.ajax({
url: url,
method: "POST",
contentType: "application/json",
data: JSON.stringify(data), // issue with a property type in the data object
dataType: "json",
error: function (e) {
console.log(e); // logging the error object to console
},
success: function () {
console.log('Success saving test result');
}
});
Now after making the request, I checked the console tab in the browser development tool.
It looked like this:
responseJSON.errors[0] clearly shows a validation error: The JSON value could not be converted to System.String. Path: $.TestId, which means I have to convert TestId to a string in the data object, before making the request.
Changing the data object creation like below fixed the issue for me:
var data = {
"TestId": String(testId), //converting testId to a string
"PlayerId": parseInt(playerId),
"Result": result
};
I assume other possible errors could also be identified by logging and inspecting the error object.

Answer 6

Your AJAX call is not completed with the following two params.
contentType: "application/json; charset=utf-8",
dataType: "json"
contentType is the type of data you're sending
dataType is what you're expecting back from the server
In addition try to use JSON.stringify() method. It is used to turn a javascript object into json string.