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How to pass data from component to controller?

Pass a string variable from the front end (HTML/.ts to C# controller).
I'm skimming through angular.io documentation and walkthroughs made by unofficial people. I watched videos and it appears none of it is relevant to my code. I started a new project(ASP.NET Core web application with Angular) in Visual Studio 2019. There are .ts components and .cs controllers. My HTML is set up to take a string input. I have tried using HTTP POST request and ajax requests. I may have done them incorrectly with the wrong arguments. I've consulted
How to send data to an ASP.NET Controller with Angular2
ASP.Net MVC How to pass data from view to controller
Passing Model data from View to Controller and using its values
AngularJS & asp.net MVC - passing data to controller?
and countless others not on StackOverflow.
.html
<input #box (keyup)="onKey(box.value)">
Your name is: {{name}}
.ts
onKey(value: string)
{
this.name = value;
}
I expect the name string to be available in the controller where I can print it out and later use it in a database.

I create a demo using asp.net core Angular template.It passes data on Keyup.
1.home.component.html
<input #box (keyup)="onKey(box.value)">
Your name is: {{name}}
2.home.component.ts
import { Component } from '#angular/core';
import { HttpClient } from '#angular/common/http';
#Component({
selector: 'app-home',
templateUrl: './home.component.html',
})
export class HomeComponent {
name: string;
constructor(
private http: HttpClient
) { }
onKey(value: string):void {
this.name = value;
const formData: FormData = new FormData();
formData.append('name', this.name);
this.http.post('https://localhost:44336/api/SampleData/TestName', formData).subscribe(result => {
console.log(result);
}, error => console.error(error));
}
}
3.SampleData controller(/api/sampleData)
[HttpPost("TestName")]
public JsonResult TestName(string name)
{
//your logic
return Json(name);
}

As per official guide line: https://angular.io/guide/user-input
<input (keyup)="onKey($event)">
onKey(event: any) {
console.log(event.target.value);
let inputValue = event.target.value;
}
Now inputValue will store your value from Input Field on Keyup Event.

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.

How do I pass multiple objects from a ViewModel to a jQuery function?

I am coding a MVC 5 internet application and would like to know how to pass values from a ViewModel into a jQuery function where I have a list of data to pass.
Usually, I would create a hidden field in the MVC View code, and then retrieve this value in the jQuery code. However, in this situation, there is not just one value from the ViewModel, but a List of objects, where each object has many values.
My ViewModel has a List<MapMarker>, where each MapMarker has the following attributes:
latitude
longitude
title
draggable
This is the jQuery function that I need to call for each MapMarker object:
function LoadMapMarker(latitude, longitude, title, draggable)
How can I call the LoadMapMarker function, with data from each of the MapMarker objects in the ViewModel list?
Thanks in advance

You can serialize your list and storage it in a hidden field. Then call LoadMapMarker by means of Javascript on client side.
Server:
using System.Web.Script.Serialization;
var MapMarkers = new List<MapMarker>();
var jsonSerialiser = new JavaScriptSerializer();
var json = jsonSerialiser.Serialize(MapMarkers);
return View(new MyViewModel({JsonList = json }));
View:
<input type="hidden" id= "MyHiddenFieldForMapMarker" value="#Model.JsonList" >
Client:
var MapMarkers = $("#MyHiddenFieldForMapMarker").val();
for (var MapMarker in MapMarkers) {
LoadMapMarker(MapMarker["latitude"],
MapMarker["longitude"],
MapMarker["title"],
MapMarker["draggable"]);
}

You can serialize to JSON and then store in a hidden field, or as a Javascript object like :
myJsonData= [{"id":"15aea3fa","firstname":"John","lastname":"Doe"}];
Alternatively, you can retrieve the data via an ajax call.

If you don't want to use JSON and use the data you have on your page you can do this:
You can add class (or some other attribute, for me it is easier to use classes, but it is better "programming" to use another attribute)
#foreach ()...
{
<div class="main_Marker">
<input ... class="lat"/> //using the #Model render ofc...
<input ... class="long"/>
</div>
}
Then jQuery:
$("main_Marker").each(function(index, item)) {
var lat = $(item).child(".lat");
.
.
LoadMapMarker(lat, long....);
}

If your jQuery function is present in a view, use #Html.Raw(Json.Encode(Model.JSonData)) like this
//JavaScript or jQuery function
function javascriptFunction()
{
var data = #Html.Raw(Json.Encode(Model.JSonData))
}
In the above code, JSonData is the name of the collection variable that contains data from model. In your case a List.
If your jQuery function is in a separate JavaScript file, then an AJAX request can be used to get the data from model
Controller Code
public ActionResult GetData()
{
//Your logic to get data from model
//Here data is the variable that holds the collection List<MapMarker>
return Json(data);
}
JavaScript Code for AJAX Request
function myJavaScriptFunction()
{
$.ajax({
url: '/GetData',
type: 'post',
success: function (data) {
alert("data retrieved successfully");
},
error: function () {
alert("Error retrieving data");
}
});
}

How to make Angular POST to C# Asp.Net MVC Controller?

I have looked around, but have not found anything (Angular post) that can actually make a successful call to a MVC Controller. I know there are a lot of Angular/.Net devs out there. Can I get some help?
Let's keep answers bare bones simple!!!
If I set a linebreak on the controller, I can see that this code is not actually hitting the controller.
HTML
<!-- I click this button -->
<input type="button" value="click" onclick="postit()" />
Javascript/Angular Post
function postit() {
$http({
method: 'POST',
url: 'Home/Give/',
data: { id: 4 }
}).success(successFn).error(errorFn);
}
function successFn() {
alert("success");
}
MVC C# Controller
[AcceptVerbs("OPTIONS")]
public ActionResult Give(int id)
{
var response = "some response" + id.ToString();
return Json(new JavaScriptSerializer().Serialize(response));
}

king Puppy, I've seen a few responses that dictate that the controller parameters should be an object that matches the object that is being sent, however, it seems that it's a little more forgiving than that. Consider the following example (I've updated your function a little):
Javascript:
$scope.postIt = function() {
var data = {
id = 4
};
$http
.post('Home/Give', data)
.success(function(data, status, headers, config) {
successFn();
})
.errors(function(data, status, headers, config) {
errorFn();
});
};
function successFn() {
alert("success");
};
function errorFn() {
alert("error");
};
MVC:
public ActionResult Give(int id)
{
var response = "some response" + id.ToString();
return Json(new JavaScriptSerializer().Serialize(response));
}
If you set a breakpoint, you will see that the id passed in is 4.
If you needed to pass in an object (so more than just one id), you could either create a matching class or struct on the controller side, or have multiple parameters (provided that they are simple value types)
ie:
public JsonResult Give (int id, int reasonId)
{
...
}
Anyway, I realize the post is old, but perhaps it will help you or others.

#kingPuppy this is my way to how to make angularjs post to mvc controller
first, html button for passing the angular js button click function;
<button class="btn btn-info" id="runButton" ng-click="runService('Hi')">Run</button>
so runService angular click (ng-click) function;
// Operation Type is my mvc controller's param
$scope.runService = function (optionType) {
$http({
url: '/System/RunService',
method: "POST",
data: {operationType : optionType}
}).then(function onSuccess(response) {
// Handle success
console.log(response);
}).catch(function onError(response) {
// Handle error
console.log(response);
});
}
And finally this is system controller's action;
NOT : Dont forget to [HttpPost] attribute
[HttpPost]
public ActionResult RunService(string operationType)
{
// Codes
Response.StatusCode = 200;
return Json(JsonRequestBehavior.AllowGet);
}
Hope this could help to you for how to make angular post to mvc controller. Thanks.

There is nothing special you have to do to get Angular to post to a standard MVC controller, and in fact I have several Angular/MVC apps that are using code almost identical to what you have above to POST to controllers that work fine.
I would use Firebug to confirm that your app is posting to the right place. One thing I noticed is that you might not want that trailing / at the end of your URL (so Home/Give instead of Home/Give/)
Good luck!

Resolve Controller Path in Javascript File

I'm using a Kendo grid to display results from a webservice. The webservice is accessed in a controller and then we point the Kendo grid dataSource to the controller like so:
JavaScript
var servicePath = "/Home/Search";
var postData = { "searchTerm" : searchTerm, "targetDB" : targetDB }
var grid = $("#grid1").kendoGrid({
pageable: {
pageSize: 10
},
dataSource: {
error: function (e) {
if (e.errors !== false) {
$("#errorContainer").html(e.errors);
}
},
transport: {
read: {
url: servicePath,
dataType: "json",
data: postData,
type: "POST"
}
},
},
dataBound: function (e) {
//Do Stuff
}
});
Controller
[HttpPost]
public ActionResult Search(string searchTerm, string targetDB)
{
//Do Search and Return JSON
}
Problem
This works wonderfully when my URL is http://localhost/Home/Index but fails whenever it's something else, such as http://localhost/ (default when project is run from root). I've experienced the same problems using a jQuery .ajax call as the kendo grid service call.
Question
So my question is, how can I put in the correct service URL for the Kendo Grid (or in general when pointing to a controller) and know it will work in all path variations?
I've tried using variations of location.host to get the full URL regardless then append the controller and method, but the Kendo service call fails with no error.
I imagine I should be able to parse the url and use what I need, but I've found that when I am at the root of the webpage I can't figure out what to put to make an ajax call work. I've tried using the controller/method and the entire url? I've also tried various techniques described below.
What am I missing? Is there a convention or technique I could use instead?
Edit
I also tried putting a hidden field on the page with a value of the controller URL:
<input type="hidden" value="#Url.Action("Search", "Home"); " id="serviceURL" />
And then using that value in the JS:
var servicePath = $("#serviceURL").val();
But I found that the value of #Url.Action() (Value : Home/Search) is the same whether your url is http://localhost/ or http:localhost/Home/Index, so no luck. This still does not work when you're on the root page where the url looks something like "localhost/".
Thanks!