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How to pass jQuery variable value to c# mvc?

How to pass jQuery variable value to c# mvc ?
I need to fetch the value of the variable btn in mvc code behind.
$('button').click(function () {
var btn = $(this).attr('id');
alert(btn);
$.ajax({
type: 'GET',
url: '#Url.Action("ActionName", "ControllerName")',
data: { id: btn },
success: function (result) {
// do something
}
});
});
Based on the variable value (Submit Button (or) Preview Button), my model will have Required validation on certain fields.
In my controller , i am calling as
[HttpGet]
public ActionResult ActionName(string id)
{
var vm = id;
return View(vm);
}
Though , ActionResult in controller is not invoked.
Jquery : alert(btn); -- is calling. I can see the alert window showing with the id. However, I am not able to retrieve the id in the controller.

You need to use jQuery.ajax() (or its shortened form jQuery.get()/jQuery.post()) with GET/POST method and set up a controller action with an argument to pass button ID:
jQuery (inside $(document).ready())
$('button').click(function () {
var btn = $(this).attr('id');
var url = '#Url.Action("ActionName", "ControllerName")';
var data = { id: btn };
// if controller method marked as POST, you need to use '$.post()'
$.get(url, data, function (result) {
// do something
if (result.status == "success") {
window.location = '#Url.Action("AnotherAction", "AnotherController")';
}
});
});
Controller action
[HttpGet]
public ActionResult ActionName(string id)
{
// do something
return Json(new { status = "success", buttonID = id }, JsonRequestBehavior.AllowGet);
}
[HttpGet]
public ActionResult AnotherAction()
{
// do something
return View(model);
}
If you want to pass retrieved button ID from AJAX into other action method, you can utilize TempData or Session to do that.

It is a nice coincidence that you use the word "fetch" to describe what you want to do.
jQuery runs in the browser as a frontend framework. Meaning that it runs on the client`s computer. Your MVC-C#-Code lies on the server. Therefore, if you want to send data between those two computers, you need to use the http protocol.
1. Ajax and REST:
Using an ajax call using http methods (post or put) to push your variable value as JSON to the backend`s REST api (route).
For this option, you might want to have a look at the fetch function of javascript.
2. HTML Forms
Use a html form where you store the variable value inside one input element. A form submission will perform a http post (by default) request to the backend as well and use all input element values as post parameters.

There are many ways to accomplish what you are looking to do, but I'll stick to using your code sample.
So what you need to do is utilize the .ajax call in jquery to send data from your view to your controller. More on that here: http://api.jquery.com/jquery.ajax/
Using your code, you'd put the .ajax call within your logic flow of what to do based on which button is clicked.
$("button").click(function ()
{
var btn = this.id;
if (btn == "previewButton")
{
$.ajax({
url: "/MyApp/MyAction",
type: "POST",
data: { btnId: btn },
dataType: "json",
async: true,
cache: false
}).success(function(data){
// do something here to validate if your handling worked
}).error(function(){
// Do something here if it doesnt work
});
}
}
You'll see that there is a URL. In my example i've chose MyApp as my controller and MyAction as the method of the controller in which we are posting values to. The ajax call posts 1 parameter with a property of btnId. If you need to pass more data, the property name in the jquery call should correspond with an argument of the actions method signature within the controller.
So my controller looks like
public MyAppController : Controller
{
[HttpPost]
public JsonResult MyAction(string btnId)
{
Debug.WriteLine("btnId: {0}", btnId);
return Json(new{ ButtonId= btnId });
}
}
This would be one way to handle passing values from your view to your controller using .ajax calls with jquery.
My preferred way is to use the Html helpers of Ajax.BeginForm which could be another option for you.
https://www.aspsnippets.com/Articles/ASPNet-MVC-AjaxBeginForm-Tutorial-with-example.aspx

Return view after ajax post to controller

I'm sending some json data with ajax by post
function SendF() {
$.ajax({
url: '#Url.Action("Summary")',
type: 'POST',
data: JSON.stringify(flags),
contentType: "application/json;charset=utf-8",
success: function() {
},
error: function() {
alert("Oops! We've experienced a connection problem!");
}
});
}
to my controller
[HttpPost]
public ActionResult Summary(List<string> flagsChecked)
{
[...]
return View(flags);
}
and tried returning a view with data I've processed, but I guess it's not gonna happen since ajax is all about asynchronous http requests. How do I change my code to be synchronous?

The whole idea behind using ajax is to give the user the partial page update experience. If you are making an ajax call and once that is done and you are doing a redirect to another page, it does not give the partial page update experience to user. It looks very similar to the normal form submit(full page submit).
If you absolutely have to send the data to server via ajax , but want to do the redirect after the ajax call is successfully finished, you can do that using javascript in the success or done callback event on the $.ajax method.
All you have to do is, set the location.href property to the new url.
var flags = ["aa", "bb", "cc"];
$.ajax({
url: '#Url.Action("Summary")',
type: 'POST',
data: JSON.stringify(flags),
contentType: "application/json;charset=utf-8"
}).done(function(res) {
window.location.href = res.newUrl;
}).fail(function(xhr, a, error) {
console.log(error);
});
This assumes that your server action method returns a JSON response with the newUrl property which contains the url you want to redirect to .
[HttpPost]
public ActionResult Summary(List<string> flagsChecked)
{
return Json(new { newUrl = Url.Action("Index","Home") });
}

One way to do this would be to send the request to the controller via ajax and then render a partial view on your page. The easiest way would be to use the built in ajax helpers in ASP MVC. Here is a link to another post that gives a pretty good overview:
How to render partial view in MVC5 via ajax call to a controller and return HTML

Asp.net MVC Checkbox Event HTTPPOST ServerSide

net mvc5 form and Using checkbox.
My condition is i need to Call HTTPPOST action immedaitely after selecting the checkbox(true)
Its something like HTTPPOST action should be called immediately after selecting the checkbox.
I need to pass Model as well to the HTTP Post.
can you please let me know whats the desired way to get this done ?

I'd recommend using jquery to achieve this. Assuming your checkbox is nested in a form, you can use:
$(function () {
$('#CheckBoxName').change(function () {
$(this).closest("form")[0].submit();
});
});
This will trigger a postback, calling the appropriate HttpPost method and sending the model as a parameter.

You should use javascript to react on a change of the checkbox then posting via ajax.
Here is an exemple :
$('#checkbox').change(function(){
if (this.checked){
var jsonModel = '#Html.Raw(Json.Encode(Model))';
$.ajax({
type: 'post',
url: '#Url.Action("UrlOfPostAction")',
data: { Model: jsonModel},
dataType: 'json',
success: function (res) {
//Do something
}
//manage errors
});
}
});

C# MVC Calling a method in different path using AJAX

I have a HomeController in my ASP.NET MVC application in folder "Controllers". My View is in: "View/Home/Index.cshtml" (look at my figure below).
I am using Ajax to get some json file every a few second. Problem is in Ajax URL, because I really don't know and didn't find, how to tell that property, that it has to go back a few folders and then find the HomeController.
My Solution looks like this:
Here is a method in my HomeController:
[HttpGet]
public ActionResult GetRandomFeed()
{
Item i = ss.getRandomFeed();
return Json(new { Source = i.Media.Source, Avatar = i.User.Avatar, Text = i.Text, Name = i.User.Name }, JsonRequestBehavior.AllowGet);
}
My AJAX in the View:
setInterval(function () {
$.ajax({
type: "GET",
url: '/HomeController.cs/GetRandomFeed', // Of course I have tried a lots of attempts in here
contentType: "application/json;", // Not sure about this
dataType: "json",
success: function (response) {
console.log("Success :)");
},
error: function() {
console.log("Error!");
}
});
}, 2000);
All I want to get that JSON file (or can be even an array of strings) and use it in my Success function. It is a simple Slide Show and JSON contains the URLs that I want to show in the page every X seconds (just changing source of an image that is in that JSON file).
I couldn't find anything like this. How to use that URL correctly OR found something similiar for WebForms but cannot use it in MVC.

Change your AJAX URL declaration to:
url: '/Home/GetRandomFeed'
Remove the .cs
Or you can also do, assuming this view is under your controller:
url: '#Url.Action("GetRandomFeed")'

In my experience, it doesn't seem enter the function is just because the JSON return from the controller doesn't include Status = "OK"
[HttpGet]
public ActionResult GetRandomFeed()
{
...
...
return Json(new
{
Status = "Ok", ...
}

Including an array with a serialize form - jquery

I currently have a form that I am trying to perform a post on (serializing the form), however I also want to include several checkboxes (but I don't want to include them in the form itself)
I have tried using jQuery's .post, but was unable to accomplish what I needed, any help would be greatly appreciated.
(I am using asp.net MVC 2.0 - and I figured this event would be attached to a button click)

There are several ways to accomplish this, I'll demonstrate two for you, along with an example of a Controller Action to accept the data:
Your Controller Action:
[HttpPost]
public ActionResult YourActionName(YourModel formModel, bool[] checkboxes)
{
...
}
.post Method:
//Serialize Form Data
var data = $("#yourForm").serializeArray();
//Iterates through all your checkboxes - with a specific class
$(".yourCheckboxClass").each(function ()
{
data.push({name : "checkboxes", value : $(this).val()});
});
.ajax Method:
//Build array of checkbox values
//You can use an .each here, or whatever other method you prefer
$.ajax({ type: "POST",
url: "<%= Url.Action("Action","Controller") %>",
datatype: "json",
traditional: true,
data: {
'formModel': $('#yourForm').serialize(),
'checkboxes': yourCheckboxArray
}
});
I hope this helps you accomplish what you need.

Would something like this work for you? (assuming the button is the submit button on the form)
$("#triggerButton").bind("click.me", function(e) {
var $form = $(this).closest("form");
$(".other-checkbox-class").appendTo($form);
});