Calling method from javascript in MVC - c#

I want to call a controller method from Javascript. I used the following code:
<input type="submit" name="button" value="Run" onclick="RunEXE"/>
I want to write the javascript to call the below function in controller.
public void Run(UserProgram userProgram)
{
SaveAndCompile(userProgram);
}
Can anyone provide me the javascript to call the function.

You can't just call a function like that. What you need to understand is that javascript runs on the client, and your function is on the server. What you need to do is make a request to the server, just like you would when loading a page, so for this you need an Action (make sure it is a POST action as we will be "posting" the request). This action can be as short as just calling the function you need:
[HttpPost]
public ActionResult RunAction(string option1)
{
//if needed, you can use the "option1" value to determine the UserProgram to pass
UserProgram userProgram = new UserProgram();
Run(userProgram);
//you can return a JSON reuslt that you can evaluate back at the client
return Json(new { #Success = true, #MyString = "a string" });
}
Then you want to use ajax to call the function from the client (javascript), for this I would recommend JQuery as it makes things much easier using post:
$.post('#Url.Action("RunAction", "MyController")',
{
option1: "some optional value"
},
function (data) {
alert("success!");
//here you have access to your JSON result via data, for example:
//data.Success = true
//data.MyString = "a string"
}
);

You can use Ajax here. jQuery ajax is very flexible and easy
Then
prepare your data to post
var myData={};// this is similar to your C# class UserProgram structure
myData.property1=value1; //etc
jQuery.ajax{(
url: '/controllerName/Run/', // or '#Url.Action("Run", "ControllerName")'
type: 'post',
data:{userProgram:myData},
success: function (data) { jQuery('#container').html(data); }
)};
or shorthand
$.post('/controllerName/Run/',{userProgram:myData}, function(result){});

Try this using JQuery:
function RunEXE() {
$.post('#Url.Action("Run", "ControllerName")',
{
userProgram: "WhatEver" //The parameter you want to pass to your action
},
function (data) {
//Code for what to do with the result.
})
};

Use the Normal AJAX method as::
On the Server side(i.e. In Controller) you are using some class/Model like 'UserProgram'
I don't know what are the Properties in that class but I have assumed it as::
public class UserProgram
{
public long ID{get;set}
public string Name{get;set}
}
this Model fields should be based on your Model that you have to pass into your AJAX code as::
var myData={ID:1,Name:"RJ"};
$.ajax{(
type: 'post',
url: '/controllerName/Run'
data:{UserProgram:myData},
success: function (data) {
$('#container').empty();
$('#container').html(data);
}
)};

To get the full description on using ajax calls in ASP.net MVC using jQuery please refer to:
http://bobcravens.com/2009/11/ajax-calls-to-asp-net-mvc-action-methods-using-jquery/

Related

Using Action in Controller every 10min [duplicate]

I have sample code like this:
<div class="cart">
<a onclick="addToCart('#Model.productId');" class="button"><span>Add to Cart</span></a>
</div>
<div class="wishlist">
<a onclick="addToWishList('#Model.productId');">Add to Wish List</a>
</div>
<div class="compare">
<a onclick="addToCompare('#Model.productId');">Add to Compare</a>
</div>
How can I write JavaScript code to call the controller action method?
Use jQuery ajax:
function AddToCart(id)
{
$.ajax({
url: 'urlToController',
data: { id: id }
}).done(function() {
alert('Added');
});
}
http://api.jquery.com/jQuery.ajax/
Simply call your Action Method by using Javascript as shown below:
var id = model.Id; //if you want to pass an Id parameter
window.location.href = '#Url.Action("Action", "Controller")/' + id;
You are calling the addToCart method and passing the product id. Now you may use jQuery ajax to pass that data to your server side action method.d
jQuery post is the short version of jQuery ajax.
function addToCart(id)
{
$.post('#Url.Action("Add","Cart")',{id:id } function(data) {
//do whatever with the result.
});
}
If you want more options like success callbacks and error handling, use jQuery ajax,
function addToCart(id)
{
$.ajax({
url: '#Url.Action("Add","Cart")',
data: { id: id },
success: function(data){
//call is successfully completed and we got result in data
},
error:function (xhr, ajaxOptions, thrownError){
//some errror, some show err msg to user and log the error
alert(xhr.responseText);
}
});
}
When making ajax calls, I strongly recommend using the Html helper method such as Url.Action to generate the path to your action methods.
This will work if your code is in a razor view because Url.Action will be executed by razor at server side and that c# expression will be replaced with the correct relative path. But if you are using your jQuery code in your external js file, You may consider the approach mentioned in this answer.
If you do not need much customization and seek for simpleness, you can do it with built-in way - AjaxExtensions.ActionLink method.
<div class="cart">
#Ajax.ActionLink("Add To Cart", "AddToCart", new { productId = Model.productId }, new AjaxOptions() { HttpMethod = "Post" });
</div>
That MSDN link is must-read for all the possible overloads of this method and parameters of AjaxOptions class. Actually, you can use confirmation, change http method, set OnSuccess and OnFailure clients scripts and so on
If you want to call an action from your JavaScript, one way is to embed your JavaScript code, inside your view (.cshtml file for example), and then, use Razor, to create a URL of that action:
$(function(){
$('#sampleDiv').click(function(){
/*
While this code is JavaScript, but because it's embedded inside
a cshtml file, we can use Razor, and create the URL of the action
Don't forget to add '' around the url because it has to become a
valid string in the final webpage
*/
var url = '#Url.Action("ActionName", "Controller")';
});
});
Javascript Function
function AddToCart(id) {
$.ajax({
url: '#Url.Action("AddToCart", "ControllerName")',
type: 'GET',
dataType: 'json',
cache: false,
data: { 'id': id },
success: function (results) {
alert(results)
},
error: function () {
alert('Error occured');
}
});
}
Controller Method to call
[HttpGet]
public JsonResult AddToCart(string id)
{
string newId = id;
return Json(newId, JsonRequestBehavior.AllowGet);
}
You can simply add this when you are using same controller to redirect
var url = "YourActionName?parameterName=" + parameterValue;
window.location.href = url;
You can set up your element with
value="#model.productId"
and
onclick= addToWishList(this.value);
I am using this way, and worked perfectly:
//call controller funcntion from js
function insertDB(username,phone,email,code,filename) {
var formdata = new FormData(); //FormData object
//Iterating through each files selected in fileInput
formdata.append("username", username);
formdata.append("phone", phone);
formdata.append("email", email);
formdata.append("code", code);
formdata.append("filename", filename);
//Creating an XMLHttpRequest and sending
var xhr = new XMLHttpRequest();
xhr.open('POST', '/Home/InsertToDB');//controller/action
xhr.send(formdata);
xhr.onreadystatechange = function () {
if (xhr.readyState == 4 && xhr.status == 200) {
//if success
}
}
}
in Controller:
public void InsertToDB(string username, string phone, string email, string code, string filename)
{
//this.resumeRepository.Entity.Create(
// new Resume
// {
// }
// );
var resume_results = Request.Form.Keys;
resume_results.Add("");
}
you can find the keys (Request.Form.Keys), or use it directly from parameters.
You can easily make a <a> link in your view.
<a hidden asp-controller="Home" asp-action="Privacy" id="link"></a>
then in you javascript code use this:
location.href = document.getElementById('link').href;

How to call C# method from Javascript in ASP.NET Core?

I have a username textbox in my Index.cshtml file and I want to check for matches in our Active Directory whenever the user changes the text inside the textbox and then maybe display it in a DropDownList, so the user can choose form it.
So I call a JavaScript function on the oninput event of the textbox and now the question is how do I call my C# method FindUser() in Index.cshtml.cs from that JS function? I have tried a lot of what I've read, ajax call doesn't work, adding [WebMethod] and making the method static doesn't work and most on the internet is on MVC which I'm not using.
Textbox in Index.cshtml:
<input type="text" class="form-control" oninput="findUsers()" />
JavaScript function:
function findUsers() {
$.ajax({
url: 'Index\FindUser',
success: function (data) {
alert(data);
},
error: function (error) {
alert("Error: " + error);
}
})
}
leads the browser to alert
Error: [object Object]
Method in Index.cshtml.cs:
public void FindUser()
{
// code
}
The method is not even called from the JS function.
Also I've read a few times that calling a C# method from the view is not the proper way of doing it. If so, how can I achieve my goal then?
I see you're using Razor pages. A method in razor page model is not a routed method (it can't be called by requesting a route), and that's why trying to send an ajax request to Index\FindUser won't work, and the error returned by server would be 404 not found.
Alternatively you can use razor page handlers.
In your Index.cshtml.cs rename the method FindUser() to OnGetFindUser() or OnGetFindUserAsync() if the method is an asynchronous method.
You can then call this method by sending a request to "Index?handler=FindUser".
// Note the difference in method name
public IActionResult OnGetFindUser()
{
return new JsonResult("Founded user");
}
function findUsers() {
$.ajax({
type: 'GET',
// Note the difference in url (this works if you're actually in Index page)
url: '?handler=FindUser',
success: function (data) {
alert(data);
},
error: function (error) {
alert("Error: " + error);
}
})
}
Further suggested read
I am not very experienced yet, I have only started programming last year, but I hope I can help a little bit.
I also had a similar problem, but I could not execute a function directly from JavaScript. You could maybe create an API call to C# and make the API execute the function you want, and then return the data back to the client.
If I don't misunderstand, you want the user to type some text, and then return from your database a list based on the typed text.
You could use an onChange in the input tag, and each time it changes, it executes an API request to the server, which will search whatever you need and return it as a json. Then in JavaScript, you parse the data and put it in a select tag.
Hope it helps.
Ok so first off, you are calling jquery inside javascript function.
Calling a controller action method from ajax is pretty easy.
https://api.jquery.com/jquery.ajax/
You need to determine the request type, the url, the datatype returned, parameters passing etc and then set a breakpoint on the controller action and on the ajax request success and error functions. Then you will be able to see why it has succeeded or failed.
The way i would do it would be to give the input an id, then when a user types text catch the event.
https://api.jquery.com/category/events/
Don't confused jquery and javascript.
Jquery is a framework that packs javascript inside it.
Javascript is the native language.
You can use onkeyup or onblur like this
onblur: When you leave the input field, a function is triggered
onkeyup: A function is triggered when the user releases a key in the
input field
Then modify your code like this
html file:
<input type="text" class="form-control" id="username" oninput="findUsers()" />
js
function findUsers() {
var username= document.getElementById("username").value;
$.ajax({
type: 'GET',
url: '/Home/FindUser
dataType: 'json',
data: {username},
success: function (data) {
console.log(data);
},
error: function (error) {
console.log(error);
}
});
}
You must return something like this. You are using void keyword so it will not return anything to FE side
public JsonResult FindUser(string username)
{
var object = {
// something here
}
return Json(object);
}
Change your API like this:
public bool FindUser(string value)
{
if (value == "Joe")
return true;
else
return false;
}
Then call it like this:
<script type="text/javascript">
function findUsers() {
var value = document.getElementById("value").value;
$.ajax({
type: 'GET',
url: '/Home/FindUser,
data: value,
dataType: 'json',
success: function (data) {
alert(data);
},
error: function (error) {
alert(error);
}
});
}
</script>
<br />
<input type="text" class="form-control" id="value" oninput="findUsers()" />
you can call method exactly you want with
small addition to Index.cshtml. First line may be:
#page "{handler?}"
then call from ajax:
url:'/index/FindUser'
in Index.cshtml.cs calling method:
void OnGetFindUser(){}

Parse JSON from C# to AngularJS

I have an array of file names:
[HttpPost]
public JsonResult GetJSONFilesList()
{
string[] filesArray = Directory.GetFiles("/UploadedFiles/");
for (int i = 0; i < filesArray.Length; i++)
{
filesArray[i] = Path.GetFileName(filesArray[i]);
}
return Json(filesArray);
}
I need this in AngularJS as a list of objects so I can ng-repeat it out and apply filters. I'm unable to figure out how to get the JSON from the MVC controller to AngularJS.
I've tried the following to make it visible to the view for angular to grab, but I don't know how to make the ng-init see the function to return the list. It erros on "SerializeObject(GetJSONFilesList())" saying it doesn't exist in current context.
<div ng-controller="MyController" data-ng-init="init(#Newtonsoft.Json.JsonConvert.SerializeObject(GetJSONFilesList()),
#Newtonsoft.Json.JsonConvert.SerializeObject(Model.Done))" ng-cloak>
</div>
EDIT:
I've tried using http.get.
Test one:
alert('page load');
$scope.hello = 'hello';
$http.get('http://rest-service.guides.spring.io/greeting').
then(function (response) {
$scope.greeting = response.data;
alert($scope.greeting);
});
alert($scope.hello);
The alert in the http.get never fires, the other alerts do however.
Test two:
$http({
url: '/Home/testHello',
method: 'GET'
}).success(function (data, status, headers, config) {
$scope.hello = data;
alert('hi');
});
[HttpPost]
public string testHello()
{
return "hello world";
}
This causes the angular to break and nothing in the .js works.
Test three
alert('page load');
$scope.hello = 'hello';
$scope.GetJSONFilesList = function () {
$http.get('/Home/testHello')
.success(function (result) {
$scope.availableFiles = result;
alert('success');
})
.error(function (data) {
console.log(data);
alert('error');
});
alert('hi');
};
alert($scope.hello);
[HttpPost]
public string testHello()
{
return "hello world";
}
Alerts nothing from within it, other alerts work.
Fixed:
After some googling, I've found that using .success and .error are deprecated and that .then should be used. So by using .then this resulted in the C# being hit via debug.
Then after using console.log on the returned value found that to have anything be returned I needed to return the value from C# using "return Json(myValue, JsonRequestBehavior.AllowGet); "
And by viewing the object in the console in Chrome by using console.log, I could see my values were in the data part of the returned object.
It was stored in data as an array (as I was passing an array).
I could then get the data out of there by assigning the returned value.data to a scope and could call that in the view {{result[1]}} etc.
return Json(filesArray, JsonRequestBehavior.AllowGet);
$scope.fileList;
$http.get("/Home/GetFileList").then(function (result) {
console.log(result)
$scope.fileList = result.data;
})
Imagine that you divide your front end in three layers (MVC or MVVM) whatever you want.
When you need info from server, the best practice is to separate the logic that makes the request and the logic that manipulates the data.
More info about how to make the request you can find it reading about REST APIS in Consuming a RESTful Web Service with AngularJS.
Normally one of the layers requires the use of services and you can have your controllers and your services (the place where you get the raw data from the server and you make the request. For that you need to use the $http service from angularjs.
$http: The $http service is a core AngularJS service that facilitates communication with the remote HTTP servers via the browser's XMLHttpRequest object or via JSONP.
So basically it shows you how to make get, post and put requests. One example from the documentation is :
// Simple GET request example:
$http({
method: 'GET',
url: '/someUrl'
}).then(function successCallback(response) {
// this callback will be called asynchronously
// when the response is available
}, function errorCallback(response) {
// called asynchronously if an error occurs
// or server returns response with an error status.
});
Pay attention to the url because there is the place where you let your request knwow which method is going to be hit on the server to take the action. If your request is succesful, then you can use the parameter called response. From there, you can do whatever you want. If you decide to make that request part from your controller, you can assign it directly to a variable on your scope. Pay attention if you need to serialize the data. Something like
$scope.myResponseName = response.name ;
The first documentation link from above shows this example which does exactly what I tell you.
angular.module('demo', [])
.controller('Hello', function($scope, $http) {
$http.get('http://rest-service.guides.spring.io/greeting').
then(function(response) {
$scope.greeting = response.data;
});
});
After all the mentioned above, pay attention to what you want to display. Are you going to display the elements of an object array? The use on your HTML the ng-repeat directive. Are you going to display just a variable (No array nor object) then you use need to use an angular expression {{ }}
In summary:
By making an HTTP request, hit the correct method on server.
Make sure you are sending the JSON correctly and that the data is correct.
Retrieve the data on your response.
Assign the data to a variable on your scope and serialize the data if needed.
Display the data correctly depending if it is within an array, if it´s an object or if its just a variable.
I hope the explanation makes sense and check the documentation if you need more info.
You can build your viewmodel so that it contains the data you'd like to serialize and then pass it to angularJS in your view as follows:
<div ng-controller="MyController" data-ng-init="init(#JsonConvert.SerializeObject(myArrayData),
#Newtonsoft.Json.JsonConvert.SerializeObject(Model.Done))" ng-cloak>
and then in your angular controller have a function to receive the data as follows:
$scope.init = function (myArrayData) {
//do something with data
};
The above assumes you're trying to pass data from mvc to angularjs on page load. If you're trying to hit a controller and get data back to angularjs upon some event such as a button click, then you can write an angularjs function similar to the following (this will be an asynchronous request):
app.controller('MyController', function ($scope, $http, $window) {
$scope.ButtonClick = function () {
var post = $http({
method: "POST",
url: "/SomeController/SomeAjaxMethod",
dataType: 'json',
data: { path: $scope.Path},
headers: { "Content-Type": "application/json" }
});
post.success(function (data, status) {
//do something with your data
});
post.error(function (data, status) {
$window.alert(data.Message);
});
}
}
and your controller action would look something like:
[HttpPost]
public JsonResult SomeAjaxMethod(string path)
{
string[] filesArray = Directory.GetFiles(path);
for (int i = 0; i < filesArray.Length; i++)
{
filesArray[i] = Path.GetFileName(filesArray[i]);
}
return Json(filesArray);
}
other answers say to use .success in the angular function, .success and .error are deprecated, instead .then should be used.
Working result:
MVC:
public JsonResult GetFileList()
{
//form array here
return Json(myArray, JsonRequestBehavior.AllowGet);
}
The function needs to be of type JsonResult, and the returned value of Json using JsonRequestBehavior.AllowGet.
AngularJS:
$scope.fileList;
$http.get("/Home/GetFileList").then(function (result) {
console.log(result)
$scope.fileList = result.data;
})
This is in my AJS controller, using .then instead of .success. If you use console.log the result returned from the mvc controller and view it in the browser inspect you'll see the object with lots of other info and the values you want are in the .data section of the object.
So to access the values you need to do result.data. In my case this gives me and array. I assign this to a scope. Then in my view I can access the values by doing {{fileList[1]}} etc. This can also be used in ng-repeat e.g:
<div ng-repeat="file in fileList">
{{fileList[$index]}}
</div>
Each value in the array in the repeat can be accessed using $index which is the number of the repeat starting at 0.

Receive parameters in action controller JSON

In ASP.NET MVC 5 with Entity Framework 6, I'm using a typical MVC Controller template with EF and I'm adding a custom action there.
My idea is to call this action from an AJAX call, to dynamically populate a select2 dropdown.
...
public JsonResult getWarrehouses(string name)
{
var warrehouses = from c in db.warrehouses
where c.nom_wrh.Contains(name)
orderby c.nom_wrh
select new { c.cod_wrh, c.nom_wrh} ;
return Json(warrehouses.ToList(), JsonRequestBehavior.AllowGet);
}
...
However, I don't know how to pass parameters to this, the parameter provided is always null. If I type: http://localhost:[port]/warrehouses/getWarrehouses/somestring the parameter is not received.
How I suppose to declare that action in order to receive GET parameters?
Feel free to provide an alternate solution if my approach is wrong.
The problem may be in the calling. For example:
the "name" is the name of your parameter on your Action;
$.ajax({
type: "POST",
url: #Url.Action("getWarrehouses"),
data: {
name: VALUE_TO_PASS
},
success: function (data) {
// Manipulate (data)
}
you need to use browser extensions like postman https://chrome.google.com/webstore/detail/postman/fhbjgbiflinjbdggehcddcbncdddomop?hl=en
they help you to make a get/post requests to getWarrehouses . with your parameters

How to call an MVC Action using only JavaScript?

I have this Kendo UI dropdownlist with a select event that is handled by a JavaScript function.
I need to call an action result from a controller that runs a LINQ query to populate a Kendo UI grid on my page. My problem is the only way I can find to handle this even is with JavaScript and I have been unable to figure out how to call my action result from my controller from the JavaScript event function.
This is what the DropDownList looks like...
#(Html.Kendo().DropDownList()
.Name("Options")
.DataTextField("Text")
.DataValueField("Value")
.BindTo(new List<SelectListItem>() {
new SelectListItem() {
Text = "Policies Not Archived",
Value = "1"
},
new SelectListItem() {
Text = "View All Policies",
Value = "2"
},
new SelectListItem() {
Text = "Filter Policies",
Value = "3"
}
})
.Events(e =>
{
e.Select("select");
})
)
and my JavaScript event handler that needs to call the action result
function select(e) {
}
and depending on the selection an ActionResult like this,
public ActionResult ViewAllPolicies()
{
//mycode
}
see this post
var url = '#Url.Action("ViewAllPolicies","YourController")';
$.ajax({ url: url, success: DataRetrieved, type: 'POST', dataType: 'json' });
in controller
public ActionResult ViewAllPolicies()
{
//Should return json format
}
url – this is the URL where request is sent. In my case there is
controller called contacts and it has action calles
ListPartiesByNameStart(). This action method takes parameter
nameStart (first letter of person or company). success – this is the
JavaScript function that handles retrieved data. You can write there
also anonymous function but I suggest you to use functions with names
because otherwise your code may get messy when functions grow. type –
this is the type of request. It is either GET or POST. I suggest you
to use POST because GET requests in JSON format are forbidden by
ASP.NET MVC by default (I will show you later how to turn on GET
requests to JSON returning actions). dataType – this is the data
format that is expected to be returned by server. If you don’t assign
it to value then returned result is handled as string. If you set it
to json then jQuery constructs you JavaScript object tree that
corresponds to JSON retrieved from server.
Instead of returning json, you can also return a PartialView and in the .done function grab an element and replace it with the results from the partial view. PartialView actions basically return a fragment of HTML, and so you can just stuff that anywhere you want on the page:
$.ajax({
url: urlToPartialViewAction,
type: 'POST',
dataType: 'JSON',
data: '123'
})
.done(function (result) {
$('#someDivPlaceholder').replaceWith(result);
});
You could have something like a link or grey div and wire up to it's click event and then call this, the link might say "View Receipt" and when you click it you call an action that returns a partial view with the receipt, and so when they click it the div/link is replaced with the result. Kind of like the "View More Comments" links you see on social sites.
Note that you can't have a partial view by itself, it must be called through an action
public PartialViewResult _GetReceipt(string id)
{
ReceiptViewModel vm = //query for receipt data
return PartialView(vm);//render partial view and return html fragment
}
Once the select function executes, you need to make an AJAX call back to your Controller. You can use jQuery.ajax() (a wrapper for the most common AJAX operations) in the select function,
function select(e) {
var url = '#Url.Action("ViewAllPolicies", "PolicyController")';
var selectedPolicy = $('#Options').val(); // The option selected
$.ajax({
url: url,
type: 'POST',
dataType: 'JSON',
data: selectedPolicy
})
.done(function (data) {
// Display the data back from you Controller
});
}
You can look at the Kendo site for more info on how the DropDownList works.

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