Making a Simple Ajax call to controller in asp.net mvc - javascript

I'm trying to get started with ASP.NET MVC Ajax calls.
Controller:
public class AjaxTestController : Controller
{
//
// GET: /AjaxTest/
public ActionResult Index()
{
return View();
}
public ActionResult FirstAjax()
{
return Json("chamara", JsonRequestBehavior.AllowGet);
}
}
View:
<head runat="server">
<title>FirstAjax</title>
<script src="http://code.jquery.com/jquery-1.9.1.js"></script>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/2.0.0/jquery.min.js"></script>
<script type="text/javascript">
$(document).ready(function () {
var serviceURL = '/AjaxTest/FirstAjax';
$.ajax({
type: "POST",
url: serviceURL,
data: param = "",
contentType: "application/json; charset=utf-8",
dataType: "json",
success: successFunc,
error: errorFunc
});
function successFunc(data, status) {
alert(data);
}
function errorFunc() {
alert('error');
}
});
</script>
</head>
I just need to print an alert with the controller method returning data. Above code just print "chamara" on my view. An alert is not firing.
UPDATE
I modified my controller as below and it start working. I don't have an clear idea why it's working now. Some one please explain. The parameter "a" does not related i added it because i can not add two methods with same method name and parameters.I think this might not be the solution but its working
public class AjaxTestController : Controller
{
//
// GET: /AjaxTest/
[HttpGet]
public ActionResult FirstAjax()
{
return View();
}
[HttpPost]
public ActionResult FirstAjax(string a)
{
return Json("chamara", JsonRequestBehavior.AllowGet);
}
}

Remove the data attribute as you are not POSTING anything to the server (Your controller does not expect any parameters).
And in your AJAX Method you can use Razor and use #Url.Action rather than a static string:
$.ajax({
url: '#Url.Action("FirstAjax", "AjaxTest")',
contentType: "application/json; charset=utf-8",
dataType: "json",
success: successFunc,
error: errorFunc
});
From your update:
$.ajax({
type: "POST",
url: '#Url.Action("FirstAjax", "AjaxTest")',
contentType: "application/json; charset=utf-8",
data: { a: "testing" },
dataType: "json",
success: function() { alert('Success'); },
error: errorFunc
});

After the update you have done,
its first calling the FirstAjax action with default HttpGet request
and renders the blank Html view . (Earlier you were not having it)
later on loading of DOM elements of that view your Ajax call get fired and displays alert.
Earlier you were only returning JSON to browser without rendering any HTML. Now it has a HTML view rendered where it can get your JSON Data.
You can't directly render JSON its plain data not HTML.

Use a Razor to dynamically change your URL by calling your action like this:
$.ajax({
type: "POST",
url: '#Url.Action("ActionName", "ControllerName")',
contentType: "application/json; charset=utf-8",
data: { data: "yourdata" },
dataType: "json",
success: function(recData) { alert('Success'); },
error: function() { alert('A error'); }
});

If you just need to hit C# Method on in your Ajax Call you just need to pass two matter type and url if your request is get then you just need to specify the url only. please follow the code below it's working fine.
C# Code:
[HttpGet]
public ActionResult FirstAjax()
{
return Json("chamara", JsonRequestBehavior.AllowGet);
}
Java Script Code if Get Request
$.ajax({
url: 'home/FirstAjax',
success: function(responce){ alert(responce.data)},
error: function(responce){ alert(responce.data)}
});
Java Script Code if Post Request and also [HttpGet] to [HttpPost]
$.ajax({
url: 'home/FirstAjax',
type:'POST',
success: function(responce){ alert(responce)},
error: function(responce){ alert(responce)}
});
Note: If you FirstAjax in same controller in which your View Controller then no need for Controller name in url. like url: 'FirstAjax',

First thing there is no need of having two different versions of jquery libraries in one page,either "1.9.1" or "2.0.0" is sufficient to make ajax calls work..
Here is your controller code:
public ActionResult Index()
{
return View();
}
public ActionResult FirstAjax(string a)
{
return Json("chamara", JsonRequestBehavior.AllowGet);
}
This is how your view should look like:
<script src="http://ajax.googleapis.com/ajax/libs/jquery/2.0.0/jquery.min.js"></script>
<script type="text/javascript">
$(document).ready(function () {
var a = "Test";
$.ajax({
url: "../../Home/FirstAjax",
type: "GET",
data: { a : a },
success: function (response) {
alert(response);
},
error: function (response) {
alert(response);
}
});
});
</script>

It's for your UPDATE question.
Since you cannot have two methods with the same name and signature you have to use the ActionName attribute:
UPDATE:
[HttpGet]
public ActionResult FirstAjax()
{
Some Code--Some Code---Some Code
return View();
}
[HttpPost]
[ActionName("FirstAjax")]
public ActionResult FirstAjaxPost()
{
Some Code--Some Code---Some Code
return View();
}
And please refer this link for further reference of how a method becomes an action. Very good reference though.

View;
$.ajax({
type: 'GET',
cache: false,
url: '/Login/Method',
dataType: 'json',
data: { },
error: function () {
},
success: function (result) {
alert("success")
}
});
Controller Method;
public JsonResult Method()
{
return Json(new JsonResult()
{
Data = "Result"
}, JsonRequestBehavior.AllowGet);
}

instead of url: serviceURL,
use
url: '<%= serviceURL%>',
and are you passing 2 parameters to successFunc?
function successFunc(data)
{
alert(data);
}

Add "JsonValueProviderFactory" in global.asax :
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
ValueProviderFactories.Factories.Add(new JsonValueProviderFactory());
}

Related

How to make Ajax call to method from controller

I have Controller PdfViewerController
inside of this controller I have a method
private static string GeneratePdfUrl(string test)
{
string aUrl;
//some action//
return aUrl
}
and I have pdfviewercontroller.js
inside or this js I want to crete a function that will return a string from Controller using GeneratePdfUrl()
something like this
function _doUrl() {
$.ajax({
type: "GET",
url: ep.utilities.replaceEPCommand('PdfViewer/GeneratePdfUrl'),
data: { "test": "R"}
});
}
what I'm doing wrong. Do I need something like .done ?
I try to create ajax Get function and expected to get string inside of my javascript
Assuming that you have an MVC Home controller
[HttpGet]
public JsonResult ForAjaxCall(string test)
{
var aUrl=GeneratePdfUrl(test);
return Json(person, JsonRequestBehavior.AllowGet);
}
This controller will call your custom method
public string GeneratePdfUrl(string test)
{
string aUrl;
//some action//
return aUrl
}
Inside your js file do something like :
function _doUrl() {
$.ajax({
type: "GET",
url: "/Home/ForAjaxCall",
data: { { "test": "R"} },
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function (response) {
alert("You got your URL "+ response.aUrl);
},
failure: function (response) {
alert("Something wrong");
},
error: function (response) {
alert(response.responseText);
}
});
}
Hope this will help you understand the flow.

How to get a string from Controller and use it in view?

I'm trying to get some string from my Controller and use it in the View.
The ActionResult works like this:
public ActionResult GetSymbols()
{
string result = "SVG-String";
return Content(result);
}
This result is will be a svg-formatted string and should be shown in my svg-drawing, at the end.
I tried to call this controller-Action, using JavaScript and I could reach the Controller but how could I use the String? I couldn't see any result, so what is the rigth way to get the returned string into a variable?
The last try was like this:
$(document).ready(function () {
$.ajax({
url: "/Symbols/GetSymbols/",
method: "GET",
async: false,
data: "",
dataType: "string",
success: function (data) { alert(data); }
});
});
How about this one,
Change your Controller return type to Json
[HttpGet]
public JsonResult GetSymbols()
{
string result = "SVG-String";
return Json(result, JsonRequestBehavior.AllowGet);
}
And your javascript be like,
$(document).ready(function () {
$.ajax({
method: "GET",
url: "/Symbols/GetSymbols/",
async: false,
dataType: "json",
success: function (data) {
alert(data);
},
error: function (response) {
console.log(response);
}
});
});

Pass json from js to controller

Data doesn't passing to controller, always null
My script in view:
function deleteRecords() {
var selected = [];
$('#myTable input:checked').each(function () {
selected.push($(this).attr('id'));
});
$.ajax({
url: '/Home/DeleteRecords',
type: 'POST',
dataType: 'json',
contentType: 'application/json; charset=utf-8',
data: { "json": JSON.stringify(selected) },
error: function () {
alert("Error!");
}
});
}
My home controller method:
[HttpPost]
public IActionResult DeleteRecords(string AllId)
{
return null;
}
send ajax request data like below,
$.ajax({
url: '/Home/DeleteRecords',
type: 'POST',
contentType: 'application/json; charset=utf-8',
data: JSON.stringify(selected),
error: function () {
alert("Error!");
}
});
and receive the data in action like
[HttpPost]
public IActionResult DeleteRecords(string[] AllId)
{
return null;
}
It need to pass the action. Hope it helps to you.
with the code in your question, try below to get the json
System.Web.Context.Current.Request.Form["json"]
if you want some more graceful stuff, you need to put FromBody attribute in your parameter signature
DeleteResults([FromBody] string json)
Name your property in the Post the same as your method so that the automatic binding picks it up. - Turns out this doesn't matter for single object.
The data Object you were creating was not parse-able by .net, use JSON.stringify directly for the data payload.
Note: The change in Home controller since you are passing an array of string.
function deleteRecords() {
var selected = [];
$('#myTable input:checked').each(function () {
selected.push($(this).attr('id'));
});
$.ajax({
url: '/Home/DeleteRecords',
type: 'POST',
dataType: 'json',
contentType: 'application/json; charset=utf-8',
data: JSON.stringify(selected),
error: function () {
alert("Error!");
}
});
}
For your home controller method:
[HttpPost]
public IActionResult DeleteRecords(string[] AllId)
{
return null;
}

Calling controller method from Javascript function

i want to call a controller method from a javascript method. I have the following code:
function test() {
$.ajax({
url: #Url.Action("abc"),
method: 'GET',
success: function(data) { alert(data); }
});
}
[HttpGet]
public string abc(string id)
{
return "Info";
}
How is it possible to get the "info" string back, in my alert() in the Javascript controller?
You need to add dataType attribute in ajax call.
Try this one:
function test() {
$.ajax({
url: #Url.Action("abc"),
method: 'GET',
dataType: "text",
success: function(data) { alert(data); }
});
}

ajax postback does not work for byte array

I am trying to sent a byte[] in a postback action, but failed to get it.
Code snippets:
$.ajax({
url: proxy.Model.RequestParamUrl,
type: "Post",
async: false,
data: proxy.requestArgs,
dataType: 'json',
success: function (Jsondata) {
proxy.allowPost = false;
proxy.postSucceed = true;
//hidden code
return true;
}
});
While debugging, I can see byte[] in proxy.requestArgs.
But in the controller, I get null in this action result.
[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Index(byte[] param)
{
//I get null in this param.
}
Anything I am missing out?
Any Solution
You're passing data to the controller action and that action is expecting a post item named param. So in your JS, make your ajax call look like this (note the change to data):
$.ajax({
url: proxy.Model.RequestParamUrl,
type: "Post",
async: false,
data: { param: proxy.requestArgs },
dataType: 'json',
success: function (Jsondata) {
proxy.allowPost = false;
proxy.postSucceed = true;
//hidden code
return true;
}
});
Have you tried this?
Basically, accept the data as string in you action and inside it convert it into byte[]
[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Index(string param)
{
var bytes = System.Text.Encoding.UTF8.GetBytes(param);
}

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