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Javascript POST to API

So I am a bit lost and hoping you can help me out. I am writing an app in simple PHP/HTML/Javascript app.
My Goal: To POST json data to an API.
How can I go about this? I just can't find any good examples to show me the best way to handle this.
In my request I need to send Basic Authorization as well as the json values.
This is what I have right now
$.ajax({
type: "POST",
url: "host.com/api/comments",
dataType: 'json',
async: false,
headers: {
"Authorization": "Basic xxxxxxxxxxxxxxxxxxxxxxx"
},
data: '{"value1":"2.0", "value2":"setPowerState", "value3":{"state":0}}',
success: function (){
alert('Comment Submitted');
}
});
I can't get the above code to work. Im using a button to call a function that will start the ajax call but nothing is happening.
Any help be be amazing! Thank You.

Use
contentType:"application/json"
You need to use JSON.stringify method to convert it to JSON format when you send it,
And the model binding will bind the json data to your class object.
The below code will work fine (tested)
$(function () {
var customer = {contact_name :"Scott",company_name:"HP"};
$.ajax({
type: "POST",
data :JSON.stringify(customer),
url: "api/Customer",
contentType: "application/json"
});
});

If you're writing the API in PHP, and it uses $_POST to get the parameters, you shouldn't send JSON. PHP only knows how to decode multipart/form-data and application/x-www-form-urlencode. If you pass an object to $.ajax, jQuery will use the urlencode format.
Just take the quotes off the object that you're passing to the data: option.
$.ajax({
type: "POST",
url: "host.com/api/comments",
dataType: 'json',
async: false,
headers: {
"Authorization": "Basic xxxxxxxxxxxxxxxxxxxxxxx"
},
data: {"value1":"2.0", "value2":"setPowerState", "value3":{"state":0}},
success: function (){
alert('Comment Submitted');
}
});
You also shouldn't use async: false, it is deprecated. Learn to write proper async code.

Nobody seems to have addressed one issue - the URL
If the page this is requested from is http://yourhost.com/path/file.html the request will be sent as http://yourhost.com/path/host.com/api/comments
As you have host.com in the URL, I assumed the request is to a different domain?
use one of
http://host.com/api/comments
https://host.com/api/comments
//host.com/api/comments
will only work if your page is loaded http and not https
will work only if the remote API supports https
will only always work properly if the remote API supports both http and https
The other issue is regarding the format of the sent data
The default content-type for $.ajax POST is application/x-www-form-urlencoded; charset=UTF-8
So, sending a POST request with various combinations of contentType and data shows the following
Firstly, without setting contentType
data: '{"value1":"2.0", "value2":"setPowerState", "value3":{"state":0}}'
request is sent as formData '{"value1":"2.0", "value2":"setPowerState", "value3":{"state":0}}'
data: {"value1":"2.0", "value2":"setPowerState", "value3":{"state":0}},
request is sent as formdata, the following values:
value1: 2.0
value2: setPowerState
value3[state]: 0
looks better, because there's actually multiple values, not just a string
Now, let's set contentType
contentType: 'json', data: {"value1":"2.0", "value2":"setPowerState", "value3":{"state":0}},
firefox does not tell me the format of the following string: 'value1=2.0&value2=setPowerState&value3%5Bstate%5D=0' - looks useless
And finally
contentType: 'json', data: '{"value1":"2.0", "value2":"setPowerState", "value3":{"state":0}}',
sends the following JSON: '{"value1":"2.0", "value2":"setPowerState", "value3":{"state":0}}'
So, finally, if the API requires JSON request data, and it's actually on a domain called "host.com"
$.ajax({
type: "POST",
url: "//host.com/api/comments",
dataType: 'json',
contentType: 'json', data: '{"value1":"2.0", "value2":"setPowerState", "value3":{"state":0}}',
});

Why error function is always fired on my ajax call? [duplicate]

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");
}

Jquery not passing any parameters data

My Code is as below for Javascript
$.ajax({
type: "POST",
url: "page/rSales.aspx",
data: { ListID: '1', ItemName: 'test' },
dataType: "json",
success: function (res) {
alert('Success');
},
error: function (res) {
alert('Fail');
}
});
I use http tracer tools to trace whether or not the parameter is passing on to my backend - and it is not. I have also tried adding contentType: 'application/json; charset=utf-8', adjust parameter by adding colon, but none of it is working.
My Backend code C# :
Request.Params["ListID"].ToString();
It always returns null, due to the parameter not passing on. I am wondering what is causing this problem and how should I resolve it.

The Request.Params collection does not support JSON requests, so you have to parse response body manually (or send it as form data).
https://msdn.microsoft.com/en-us/library/system.web.httprequest.params(v=vs.110).aspx says "Gets a combined collection of QueryString, Form, Cookies, and ServerVariables items."

For firefox you declare var event; before your ajax call this is very well known issue in firefox.

SyntaxError: missing ; before statement jquery jsonp

I am using below code to access rest service hosted on another domain.
$.ajax({
type: 'GET',
url: url,
async: false,
jsonpCallback: 'jsonCallback',
contentType: "application/json",
dataType:"jsonp",
success: function(json) {
alert(json);
},
error: function(e) {
console.log(e.message);
}
});
I am able to get the data correctly, but I get this error in firebug in mozilla:
SyntaxError: missing ; before statement
{"Hello":"World"}
Can anyone suggest me what I am doing wrong here? Even though Json data is valid. I tried all the suggestions posted in this question But still I am getting same error.

If it's really JSON you ask for, don't set "jsonp" as dataType, and don't provide a callback :
$.ajax({
type: 'GET',
url: url,
contentType: "application/json",
success: function(json) {
alert(json);
},
error: function(e) {
console.log(e.message);
}
});

the format of JSON and JSONP are slightæy different
JKSONP is a function invocation expression
callback({"hellow":"world"});
whereas JSON is simply a serialized object
{"Hello":"world"}
fromyour posting it would seem that the server is returning JSON and not JSONP
So you either need to change the server to reply correctly (The actual callback name is a get parameter to the request). You should do this if you are using the ajax call across domains
If you are not using ajax across domains stick to regular JSON

jQuery Ajax PUT not firing

The following ajax works exactly as advertised in Chrome. HTTP PUT is used to trigger the insertion of an object into a RESTful API.
$.ajax({
type: "PUT",
url: "/ajax/rest/team/create/",
dataType: "json",
processData: false,
data: JSON.stringify(teamObject),
success: function (response) {
teamObject = response.object;
}
});
I note that the jQuery API docs helpfully tell me that PUT and DELETE may work but are not guaranteed in all browsers. Such as is my problem.
How is a RESTful API supposed to be implemented on the client side with a problem like this?
EDIT: Firebug tells me that FF is indeed issuing a PUT, but for some currently unknown reason it's dying before getting to the server. To repeat, this works fine in Chrome.
EDIT: Fiddler doesn't see the FF attempt at all. :(

I got the following to work.
var payload = JSON.stringify(teamObject)
syncHTTP('/ajax/rest/team/create/', 'PUT', payload);
function syncHTTP(url,method,payload) {
var client = new XMLHttpRequest();
client.open(method, url, false);
client.setRequestHeader("Content-Type", "text/plain");
client.send(payload);
}
I'd rather use jQuery than roll my own tho. :| If anyone ever figures it out, just add an answer and if it works I'll accept it.
Thanks.

$.ajax({
type: "PUT",
url: "/ajax/rest/team/create/",
dataType: "json",
contentType: "application/json",
processData: false,
data: JSON.stringify(teamObject),
success: function (response) {
teamObject = response.object;
}
});
You need to add contentType. When contentType is set to application/json jquery do not try to create JSON object from JSON string but send it as is - as string.