AJAX not resolving url correctly - javascript

I have an HTML form that I want to submit to a flask endpoint, /add_int. When the form is submitted I intercept it with Jquery and submit the form to the endpoint using AJAX as follows:
var form = $( this ).serialize()
$.post({
url: "{{ url_for('add_int') }}",
data: JSON.stringify(form),
contentType: 'application/json;charset=UTF-8',
success: function(resp) {
console.log(resp);
}
});
The endpoint looks like this:
#app.route('/add_int', methods=['GET', 'POST'])
#login_required
def add_int():
# do stuff
return jsonify(status="success!")
My issue is that I never get to the endpoint.
When I examine my console I see
POST http://127.0.0.1:5000/[object%20Object] 404 (NOT FOUND)
instead of
POST http://127.0.0.1:5000/add_int
as I'd expect.
Note that if I set
url: '/add_int',
I run into the same problem.
I've found cases that use almost identical code that don't mention this problem:
e.g. how can I use data posted from ajax in flask?
My guess, is that my url is being resolved as a String object rather than a url, but I can't figure out why it's happening, and how to fix it.
What's going on?

You should remove the call to JSON.stringify, you can pass a serialized form directly as POST data and JSON.stringify is turning your object into [Object object].
url: '/add_int', isn't working because (it appears that) your frontend is running on a different port than the backend, so it will be rejected as a "cross domain" request. Have you inspected the value that "{{ url_for('add_int') }}" is returning?

Try not specifying the hash keys explicitly. http://api.jquery.com/jquery.post/
$.post("{{ url_for('add_int') }}",
JSON.stringify(form),
function(resp) {
console.log(resp);
},
'application/json;charset=UTF-8'
);

Related

How to get all the data of an ajax data into django without using request.post

I want to get the data part of an ajax request into django as a dictionary without using request.post['name']
$.ajax({
url: "getAppointments",
method: "POST",
data: data, //I want to get this data as a dictionary in django
context: document.body,
}).done(function(data) {
alert("Successfully Edited");
}).fail(function(returnedText) {
window.alert("An error has occurred. Check log for details"+returnedText.responseText);
console.log(returnedText.responseText);
});
The client-size (your ajax request), and server-size (django) are two separate entities. Thus, you will have to parse the data coming into your getAppointments route like any other request body.
Regardless, request.POST in django is already a dictionary-like object: https://docs.djangoproject.com/en/2.1/ref/request-response/#querydict-objects
Stringify your JSON data and then receive it with json.loads() method in your Django view.
# Ajax
dataType: 'json',
data: {'my_dict': JSON.stringify(data)}
# views.py
my_dict = json.loads(request.POST.get('my_dict'))

Jquery: Probably a syntax Issue in ajax() method - Value not getting sent

I'm able to dump value of the variable message in console .
But im not able to send it off in POST Request.
AJAX call:
chat.throwmsg = function(message) {
if ($.trim(message).length != 0) {
console.log(message);
$.ajax({
url: 'ajax/chat.php',
type: 'post',
data: { method: 'throw', message: message} ,
success: function(data) {
chat.fetchmsgs();
$('textarea#entry').val('');
}
});
}
}
This maybe due to wrong syntax, but I've tried both single and double quotes, and combination as well .
With a wild assumption, you are not having any error messages in developer console and chat.php has a post handler forthese parameters
Since your data is JSON, please change the code as this way and have a try..
var temp={ method: 'throw', message: message};
var param=JSON.stringify(temp);
$.ajax({
url: 'ajax/chat.php',
type: 'post',
data: param ,
dataType: "json",
success: function(data) {
chat.fetchmsgs();
$('textarea#entry').val('');
}
});
after reviewing the code I could not find any issues that restrict the data to be sent along with ajax request,if you are having any syntax errors you should have been warned prior the request initialization, however I recommend you to check the request header in the network tab of browser console and see your sending data along with the request if it's there you probably need to check the code of getting the post data in your server-side implementations

jQuery $.ajax done callback not firing

I have the following code :
$("#loginSubmitButton").on("click",function(){
var loginUserDetails = {
email: $("#email").val(),
password: $("#password").val()
};
//Send the AJAX request to authenticate the user
$.ajax({
type: "POST",
url: "/somewebservice/v1/users/authenticate",
data: JSON.stringify(loginUserDetails),
contentType: "application/json;charset=UTF-8",
dataType: "json",
}).done(function() {
$("#loginResult").text("Login successful");
})
.fail(function() {
$("#loginResult").text("Login failed");
});
});
As per the jquery documentation (unless I am understanding something incorrectly) I expect the done to be fired if I receive a 200 OK from my web server. However, in chrome console I can see a 200 OK response but jquery seems to fire the fail handler.
Does anyone have any idea what I might be doing wrong here?
You need to remove:
dataType: "json"
There are lots of suggestions to remove
dataType: "json"
While I grant that this works it's probably ignoring the underlying issue. It's most likely caused by a parser error (the browser parsing the json response). Firstly examine the XHR parameter in either .always() or .fail().
Assuming it is a parser fail then why? Perhaps the return string isn't JSON. Or it could be errant whitespace at the start of the response. Consider having a look at it in fiddler. Mine looked like this:
Connection: Keep-Alive
Content-Type: application/json; charset=utf-8
{"type":"scan","data":{"image":".\/output\/ou...
In my case this was a problem with PHP spewing out unwanted characters (in this case UTF file BOMs). Once I removed these it fixed the problem while also keeping
dataType: json
If your server returns empty string for a json response (even if with a 200 OK), jQuery treats it as failed. Since v1.9, an empty string is considered invalid json.
Whatever is the cause, a good place to look at is the 'data' parameter passed to the callbacks:
$.ajax( .. ).always(function(data) {
console.log(JSON.stringify(data));
});
Its contents will give you an understanding of what's wrong.
Need to remove , from dataType: "json",
dataType: "json"
The ajax URL must be the same domain. You can't use AJAX to access cross-domain scripts. This is because of the Same Origin Policy.
add "dataType:JSONP" to achieve cross domain communication
use below code
$.ajax({
URL: cross domain
dataType: 'jsonp'
// must use dataType:JSONP to achieve cross domain communication, otherwise done function would not called.
// jquery ajax will return "statustext error" at }).always(function(data){}
}).always(function(data){
alert(JSON.stringify(data));
}
A few things that should clear up your issue and a couple hints in general.
Don't listen for a click on a submit button. You should wait for the submit event on the form.
The data option for $.ajax isn't expecting a JSON string. It wants a serialized string or an array with name and value objects. You can create either of those easily with .serialize() or .serializeArray().
Here is what I was thinking for your script.
$('#form-with-loginSubmitButton').on('submit', function(e){
e.preventDefault():
var $form = $(this),
data = $form.serializeArray();
$.ajax({
type: "POST",
url: "/somewebservice/v1/users/authenticate",
data: data
}).done(function(result){
console.log(result);
});
});

Ajax request returns 200 OK, but an error event is fired instead of success

I have implemented an Ajax request on my website, and I am calling the endpoint from a webpage. It always returns 200 OK, but jQuery executes the error event.
I tried a lot of things, but I could not figure out the problem. I am adding my code below:
jQuery Code
var row = "1";
var json = "{'TwitterId':'" + row + "'}";
$.ajax({
type: 'POST',
url: 'Jqueryoperation.aspx?Operation=DeleteRow',
contentType: 'application/json; charset=utf-8',
data: json,
dataType: 'json',
cache: false,
success: AjaxSucceeded,
error: AjaxFailed
});
function AjaxSucceeded(result) {
alert("hello");
alert(result.d);
}
function AjaxFailed(result) {
alert("hello1");
alert(result.status + ' ' + result.statusText);
}
C# code for JqueryOpeartion.aspx
protected void Page_Load(object sender, EventArgs e) {
test();
}
private void test() {
Response.Write("<script language='javascript'>alert('Record Deleted');</script>");
}
I need the ("Record deleted") string after successful deletion. I am able to delete the content, but I am not getting this message. Is this correct or am I doing anything wrong? What is the correct way to solve this issue?
jQuery.ajax attempts to convert the response body depending on the specified dataType parameter or the Content-Type header sent by the server. If the conversion fails (e.g. if the JSON/XML is invalid), the error callback is fired.
Your AJAX code contains:
dataType: "json"
In this case jQuery:
Evaluates the response as JSON and returns a JavaScript object. […]
The JSON data is parsed in a strict manner; any malformed JSON is
rejected and a parse error is thrown. […] an empty response is also
rejected; the server should return a response of null or {} instead.
Your server-side code returns HTML snippet with 200 OK status. jQuery was expecting valid JSON and therefore fires the error callback complaining about parseerror.
The solution is to remove the dataType parameter from your jQuery code and make the server-side code return:
Content-Type: application/javascript
alert("Record Deleted");
But I would rather suggest returning a JSON response and display the message inside the success callback:
Content-Type: application/json
{"message": "Record deleted"}
You simply have to remove the dataType: "json" in your AJAX call
$.ajax({
type: 'POST',
url: 'Jqueryoperation.aspx?Operation=DeleteRow',
contentType: 'application/json; charset=utf-8',
data: json,
dataType: 'json', //**** REMOVE THIS LINE ****//
cache: false,
success: AjaxSucceeded,
error: AjaxFailed
});
I've had some good luck with using multiple, space-separated dataTypes (jQuery 1.5+). As in:
$.ajax({
type: 'POST',
url: 'Jqueryoperation.aspx?Operation=DeleteRow',
contentType: 'application/json; charset=utf-8',
data: json,
dataType: 'text json',
cache: false,
success: AjaxSucceeded,
error: AjaxFailed
});
This is just for the record since I bumped into this post when looking for a solution to my problem which was similar to the OP's.
In my case my jQuery Ajax request was prevented from succeeding due to same-origin policy in Chrome. All was resolved when I modified my server (Node.js) to do:
response.writeHead(200,
{
"Content-Type": "application/json",
"Access-Control-Allow-Origin": "http://localhost:8080"
});
It literally cost me an hour of banging my head against the wall. I am feeling stupid...
I reckon your aspx page doesn't return a JSON object.
Your page should do something like this (page_load)
var jSon = new JavaScriptSerializer();
var OutPut = jSon.Serialize(<your object>);
Response.Write(OutPut);
Also, try to change your AjaxFailed:
function AjaxFailed (XMLHttpRequest, textStatus) {
}
textStatus should give you the type of error you're getting.
I have faced this issue with an updated jQuery library. If the service method is not returning anything it means that the return type is void.
Then in your Ajax call please mention dataType='text'.
It will resolve the problem.
You just have to remove dataType: 'json' from your header if your implemented Web service method is void.
In this case, the Ajax call don't expect to have a JSON return datatype.
See this. It's also a similar problem. Working I tried.
Dont remove dataType: 'JSON',
Note: Your response data should be in json format
Use the following code to ensure the response is in JSON format (PHP version)...
header('Content-Type: application/json');
echo json_encode($return_vars);
exit;
I had the same issue. My problem was my controller was returning a status code instead of JSON. Make sure that your controller returns something like:
public JsonResult ActionName(){
// Your code
return Json(new { });
}
Another thing that messed things up for me was using localhost instead of 127.0.0.1 or vice versa. Apparently, JavaScript can't handle requests from one to the other.
If you always return JSON from the server (no empty responses), dataType: 'json' should work and contentType is not needed. However make sure the JSON output...
is valid (JSONLint)
is serialized (JSONMinify)
jQuery AJAX will throw a 'parseerror' on valid but unserialized JSON!
I had the same problem. It was because my JSON response contains some special characters and the server file was not encoded with UTF-8, so the Ajax call considered that this was not a valid JSON response.
Your script demands a return in JSON data type.
Try this:
private string test() {
JavaScriptSerializer js = new JavaScriptSerializer();
return js.Serialize("hello world");
}

Can not get json response using $.getJSON

I am currently developing a Ruby on rails 3 application.
My server controller function render a json object as response:
class DaysController < BaseController
...
def the_days
...
render :json => days
end
end
In my javascript,I use the following code to get json response from server( that's from the_day function in controller)
$.getJSON(
url,
{emp_id: emp_id},
function(data) {
var result = data.response;
alert(result)
alert(data)
},
"json"
);
I use firefox browswer and checked with Firebug, in Firebug Net->XHR, I see the Get request is successful, and the response "days" is there. That's both request and response are successful.
But I did not see the two alert window defined in the above $.getJSON function, why? Why I can not get the response "days" in $.getJSON function??
-----------------Edited------------------
I edited my code to this one:
$.ajax({
url: myURL,
type: 'GET',
data: {
emp_id: emp_id
},
dataType: "json",
success: function(data) {
alert("hi");
alert(data)
}
});
When I run this code, the browser is stuck at success: function(data)
If data is coming back null, but the response was otherwise successful, I'd say that you're sending the request in a manner that violates the Same Origin Policy.
The request needs to be sent to the same host/port/protocol that served the original page.
If this is only an issue in your development environment, you can test in Chrome by launching it from a Terminal application with --disable-web-security.
EDIT: Try changing the parameter name from data to something else, like dat or whatever.
Then try an alert:
alert( dat );
I've heard of some browsers having trouble with the data parameter when you utilize the data property of an AJAX call.
I'm guessing that the problem is that data does not have a response property. Try alerting just the data variable. It should be the days object itself.
I wish I could just leave a comment but I guess I don't have access to that yet.
Anyway, I'd start with something even more basic. Add some text alerts just to make sure you're actually making it to where you think you are. ie...
$.getJSON(
url,
{emp_id: emp_id},
function(data) {
alert('hi') // add this
var result = data.response;
alert('bye') // add maybe even this
alert(result)
alert(data)
},
"json"
);
Sometimes when I'm debugging I find that even my most basic assumptions are wrong.
Edit: here's some sample code from working code I recently implemented
$.ajax({
url: 'users/check_username',
type: 'GET',
data: {
username: username
},
dataType: "json",
success: function(user_exists) {
alert(user_exists) // CHANGE THIS PART
}
});
It sounds like you are not sending the correct header in your ruby application. Firebug should report the response Content Type as application/json because that is what jquery is expecting it to be.
You could try changing the datatype in your ajax call to html to see if your alerts work with that, but that doesn't really help with the json parsing.
ALL, finally, I figured out the root cause. The reason is simply because of "Invalid json data" returned in server. That's in rails controller function 'def the_days':
render :json => days
should be modified to
render :json => days.to_json
Then, everything works smoothly:) Thank you all anyhow!

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