ASP.NET: Ajax doesn't send string - javascript

I have this method to send some data with ajax:
function SendData(foodID, basketID) {
var data = { FoodID: foodID, BasketID: basketID };
$.ajax({
url: '/Order/Post',
type: 'POST',
data: JSON.stringify(data),
contentType: 'application/json;utf-8',
datatype: 'json'
}).done(function (data) {
console.log(data);
}).fail(function (data) {
console.log("Error: " + data);
});
}
In C#, my Post Method in my Order controller gets triggered, but the string I want to hand over is null:
public bool Post(string s)
{
//When this gets executed, s is null
return true;
}
I tested this by executing SendData(1,1) directly on a button click. What is the mistake I'm doing and how can I get the string in my Post-Method?

you are post the object. not string.
you can try generate to object and load this object. or add new one parameter to action (foodId and basketId but you must post like that if you check this option data:{foodId,basketId})
//model
public class SomeObject{
public string FoodId {get;set;}
public string BasketId {get;set;}
}
//code
public bool Post(SomeObject data)
{
return true;
}

It seems for me your data structure to the Post action doesn't match action parameter names. Try this:
[HttpPost]
public bool Post(string foodID, string baskedID)
{
return true;
}

I believe you have to name your data that's being passed like so:
data: { 's': JSON.stringify(data) }

Related

Return parameter null in controller from ajax

I don't know what happened the value sent to the controller is always null, even though in the console.log the value is there, please I need help
this is my ajax:
$('#ddlItemName').change(function () {
var ItemCode = $('#ddlItemName').text();
if (ItemCode != '') {
var RequestParam = {
search: ItemCode
}
console.log(RequestParam);
$.ajax({
url: '/Order/CustomerItemOrders',
type: 'POST',
data: JSON.stringify(RequestParam),
contentType: 'application/json; charset=utf-8',
success: function (data) {
alert(data[0].Name);
},
error: function (data) {
toastr.error(data);
}
});
}
$('#ddlItemName').text('');
});
This is my controller :
[HttpPost]
public JsonResult CustomerItemOrders([FromBody] string search)
{
var result = _order.BindCustomerOrders(search);
return Json(result.data);
}
This is my error :
enter image description here
I've tried adding '[FromBody]' but the value parameter still doesn't get sent
I recomend you add the parameter to query
If you insist on pass the value with request body
Try creat a model:
public class SomeModel
{
public string search{get;set;}
}
in your controller:
public JsonResult CustomerItemOrders([FromBody] SomeModel somemodel)
{
.......
}

json string on POST to MVC action method using AJAX is null

I am getting a hard time to find out why the string sent via AJAX request is null. Console.WriteLine(data) shows empty. Status is 200 OK. If I add some code to parse the string received, I get an error stating that JObject.Parse cannot be null. I don't know what am I missing. The javascript code is ok. The action method also seems ok, but my knowledge on Asp.Net Core and MVC is very scarce, so I am not sure. Can someone please point out what am I missing?
The javascript code:
let obj = {email: email_address.value};
let objStringified = JSON.stringify(obj);
$.ajax({
type: 'POST',
contentType: 'application/json; charset=UTF-8',
data: objStringified,
url: '#Url.Action("ReturnCheckAccountDuplication")',
dataType: 'text',
success: function(data) {
console.log(data);
},
error: function(error) {
console.log("Keep trying", error);
}
});
C# code:
[HttpPost]
public ActionResult ReturnCheckAccountDuplication([FromBody] string data)
{
Console.WriteLine(data);
JObject jObject = JObject.Parse(data);
string email = (string)jObject["email"];
bool emailExists = CheckAccountDuplication.Get(email);
string returnResult = emailExists.ToString();
return Content(returnResult);
}
The solution on the controller side is
public class AccountCheckModel
{
public string Email { get; set; }
}
[HttpPost]
public ActionResult ReturnCheckAccountDuplication([FromBody] AccountCheckModel data)
{
string result = CheckAccountDuplication.Get(data.Email).ToString();
return Content(result);
}
Thanks to all the members who commented on my problem, especially John Glenn who provided a solution. I had been trying for several days but without success. My knowledge of Asp.Net Core is very poor indeed. Thank you very much.
The easiest solution is to create a model representing the JSON data that your controller will receive. For example, create a class like so:
public class AccountCheckModel
{
public string email { get; set }
}
Then, use it as the parameter for your controller method:
public ActionResult ReturnCheckAccountDuplication([FromBody] AccountCheckModel data)
This is the preferred way to access the request body. To get the request body as a string, you have to jump through some serious hoops.
An alternative way to send your data via AJAX to your Controller:
var json = {
email: email_address.value
};
$.ajax({
type: 'POST',
data: {'json': JSON.stringify(json)},
url: '#Url.Action("ReturnCheckAccountDuplication")',
dataType: 'json',
success: function(data) {
console.log(data);
},
error: function(error) {
console.log("Keep trying", error);
}
});
And your Controller:
[HttpPost]
public ActionResult ReturnCheckAccountDuplication(string json)
{
Console.WriteLine(json);
JObject jObject = JObject.Parse(json);
string email = (string)jObject["email"];
bool emailExists = CheckAccountDuplication.Get(email);
string returnResult = emailExists.ToString();
return Content(returnResult);
}

Ajax POST an object with javascript, but the value in backend is null, why?

So on button click there is a function sendEmail(). Alert is working fine, I can see my datas there. But on backend I can't see anything, just everything is null.
function sendEmail() {
var datas = new Object();
datas.mail = $('#contactDropdownList').val();
datas.mailobject = $('#emailObject').val();
datas.text = $('#emailText').val();enter code here
alert(datas.mail + datas.mailobject + datas.text);
$.ajax({
type: "POST",
dataType: "json",
url: "/Email/sendEmail",
contentType: 'application/json; charset=UTF-8',
data: JSON.stringify({ items: datas }),
success: function (data) {
console.log(data);
//do something with data
},
error: function (jqXHR, textStatus, error) {
//log or alert the error
console.log(error);
}
});
}
C# code:
public class MyClass
{
public string Email { get; set; }
public string Object { get; set; }
public string Text { get; set; }
}
[HttpPost]
public IActionResult sendEmail(MyClass items)
{
return Json(new { data="Ok" });
}
items.Email, items.Object and items.Text are null.
And the return valu is null as well, because in javascript success: function (data) { console.log(data);
is empty string.
What can be the problem? Thank you!
Model binder expects json content to match C# class. Your datas object should look like that
var datas = {
email: $('#contactDropdownList').val(),
object: $('#emailObject').val(),
text: $('#emailText').val()
}
Since you wrapped your object ({ items: datas }), you may think it will be mapped to sendEmail(MyClass items), but in reality items name does not matter, you can change variable name to any other name you like
Make sure you apply [FromBody] attribute to your parameter like that
[HttpPost]
public IActionResult sendEmail([FromBody]MyClass items)
Complete demo:
<script>
function sendSmth() {
var data = {
Email: 'email',
Object: 'object',
Text: 'text'
};
$.ajax({
type: "POST",
dataType: "json",
url: "/home/index",
contentType: "application/json",
data: JSON.stringify(data),
success: function (datas) {
console.log(datas)
}
})
}
</script>
And controller
[HttpPost]
public IActionResult Index([FromBody]MyClass obj)
{
return View();
}
As someone has noted, you have a mismatch between what you're sending to the controller and what the model the modelbinder is expecting. You can also vastly simply your AJAX code:
function sendEmail() {
var data = {
Email: $('#contactDropdownList').val(),
Object: $('#emailObject').val(),
Text: $('#emailText').val()
};
$.post("/Email/sendEmail", data)
.done(function (response) {
console.log(response);
//do something with response
})
.fail(function (jqXHR, textStatus, error) {
//log or alert the error
console.log(error);
});
}
You don't really need to specify the content type or data type - the $.post helper's defaults work just fine for what you've shown.

Ajax POST and Stringify Confusion

I am learning about POST with Ajax and I've noticed a lot of examples using stringify on static arrays.
In my example I am building array via jQuery objects extracted from <input> values.
Jquery
function PostEdit(vData){
var content = JSON.stringify(vData); //content = "[{"Id":"1","Date":"7/12/2017 12:00:00 AM"}]"
$.ajax({
url: '#Url.Action("Index", "PostViewData")',
type: "POST",
data: JSON.stringify({ ViewData : vData }),
contentType: "application/json",
success: function (result) {
alert("success" + result);
},
error: function (result) {
alert("failure" + result);
}
});
return;
}
Controller
[HttpPost]
public ActionResult Index(List<DataViewModel> ViewData )
{
if(ViewData != null)
{
var json = new { success = true };
return Json(json);
}
return Json(false);
}
ViewModel
public class DataViewModel
{
public DataViewModel(string id, string date)
{
Id = id;
Date = date;
}
public string Id { get; set; }
public string Date { get; set; }
}
Where DataViewModel is a class that consists of two values, Id, and Date which correspond to my JS object.
Since vData enters the function as value vData = [Object], When I call .stringify(vData) it returns content = "[{"Id":"1","Date":"7/12/2017 12:00:00 AM"}]"
The value of content above is how I see most examples structured before stringify such as the example here.
Once in this format, this is when most responses, examples call stringify anyway.
Now when I call .stringify(ViewData : vData) I dont even make it to the controller. Ajax fails to post. On the contrary when I call .stringify(ViewData : content), I make it to the controller, but with a null value. What am I missing / misunderstanding?
I'm looking for a better explanation of Ajax Post and Stringify, and how it interacts with the controller parameter.
Just add parameterless constructor to your model. With that change, your code will work as it is. ASP is unable to parse your json as DataViewModel since it's trying to call default constructor that doesn't exists.
public class DataViewModel
{
public DataViewModel()
{
}
//...other methods and members here
}
Please try the solution below.
There's another way of doing this
function PostEdit(vId, vDate){
$.ajax({
url: '/PostViewData/Index' // it should be '/controller/method'
type: "POST",
data: JSON.stringify({ Id: vId, Date: vDate}),
contentType: "application/json",
success: function (result) {
alert("success" + result);
},
error: function (result) {
alert("failure" + result);
}
});
return;
}
[HttpPost]
public ActionResult Index(string Id, string Date )
{
if(Id != null)
{
var json = new { success = true };
return Json(json);
}
return Json(false);
}
Update: In the controller method, it should be string id, string date
Update: The constructor should be parameterless. From the answer mentioned below
public DataViewModel()
{
}

getting null value in list when passing by ajax call to mvc controller

I am passing my list to an mvc controller but I am getting null value in the controller.But my list has values when show in alert on client side.
ajax call
$("#addTiles").click(function() {
userTiles = JSON.stringify({
'userTiles': userTiles
});
alert("Entered function.");
alert(userTiles[0].TileID);
var url = '#Url.Action("AddTiles")';
$.ajax({
type: "GET",
url: url,
data: userTiles,
success: function(d) {
if (d.indexOf('"IsSessionExpired":true') != -1) {
location.reload();
} else {
onAddTilesSuccessful(d);
}
},
error: function() {
errorInOperation();
},
contentType: "application/html; charset=utf-8",
dataType: 'html'
});
});
function onAddTilesSuccessful(e) {
$("#tilesSubmissionMsg").append(e);
}
function errorInOperation(d) {
$("#tilesSubmissionMsg").append("Something went wrong");
}
mvc controller
public ActionResult AddTiles(List<UserTilesVM> userTiles)
{
return View();
}
List Model
public class UserTilesVM
{
public int TileID { get; set; }
public int TopPosition { get; set; }
public int LeftPosition { get; set; }
}
List in javascript
"{"userTiles":[{"TileID":"3","TopPosition":0,"LeftPosition":0}]}"
I have also tried by sending my list with stringfy but that also doesn't work.
Use : [HttpGet] on the method AddTiles as you have used type: "GET" on the Ajax hit.
[HttpGet]
public ActionResult AddTiles(List<UserTilesVM> userTiles)
{
return View();
}
If Still doesn't works then try type: "POST" on Ajax hit and on method use [HttpPost]
[HttpPost]
public ActionResult AddTiles(List<UserTilesVM> userTiles)
{
return View();
}
You have contentType and dataType twice in your AJAX setup, with different values, which will break the AJAX call.
Keep in mind contentType is to tell the server what type of data to expect and dataType is to determine what type of data is returned, from the documentation.
Edit: I see you have edited your code!
In this case, since you are using JSON.Stringify to modify the data you are sending, you would use contentType: "application/json; charset=utf-8", as your contentType, since you are sending JSON data to the backend.
when we are trying to pass object data using ajax, we have to store data in variable and pass data directly using "data :'variable'" in AJAX to Controller Method
$("#addTiles").click(function() {
var userTiles = ({
'userTiles': userTiles
});
alert("Entered function.");
alert(userTiles[0].TileID);
var url = '#Url.Action("AddTiles")';
$.ajax({
type: "POST",
url: url,
data: userTiles,
success: function(d) {
if (d.indexOf('"IsSessionExpired":true') != -1) {
location.reload();
} else {
onAddTilesSuccessful(d);
}
},
error: function() {
errorInOperation();
},
contentType: "application/html; charset=utf-8",
dataType: 'html'
});
});
function onAddTilesSuccessful(e) {
$("#tilesSubmissionMsg").append(e);
}
function errorInOperation(d) {
$("#tilesSubmissionMsg").append("Something went wrong");
}
//Use [HttpPost] keyword for getting value which was passed by AJAX.
[HttpPost]
public ActionResult AddTiles(List<UserTilesVM> userTiles)
{
return View();
}
I think your list definition is not ok:
"{"userTiles":[{"TileID":"3","TopPosition":0,"LeftPosition":0}]}"
should be:
"{"userTiles":[{"TileID":"3","TopPosition":"0","LeftPosition":"0"}]}"
i have using this sequence that work fine
you have check the
contentType: "application/json",
dataType: "json",
sequence in ajax method

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