MVC Controller Different Behavior between Form Submit and Ajax call - c#

I am pretty new to MVC and web development in general so please bear with me.
In my web app, I am trying to call a controller action via an Ajax request as I only want to refresh the partial view in my page as opposed to the entire page. Everything works properly (the Partial View is returned without refreshing the main View) except the Partial View returns the wrong values. After some debugging I discovered the error was with the Request statements in the controller action. When the controller action is called by a normal form submit, the Requests are able to get the user input values, but not when I call the controller with an Ajax request; they simply return null values.
Please see the below example, it is a much much simplified version of what I am facing. When using Ajax, the total always ends up being 0 due to the parse commands failing on a null value.
Controller:
[HttpPost]
public ActionResult Calculate() {
ViewBag.Total = 0;
for(int i = 1; i < 10; i++) { // max number of Frames that users can add is 10
string FrameNumber = i.ToString;
try {
string rawValue1 = Request["input1_Frame" + FrameNumber];
string rawValue2 = Request["input2_Frame" + FrameNumber];
decimal Value1 = decimal.Parse(rawValue1);
decimal Value2 = decimal.Parse(rawValue2);
ViewBag.Total += Value1 + Value2;
} catch {
break;
}
return PartialView("Banner");
}
JQuery:
$("#calculate").on("click", function () {
$.ajax({
cache: false,
dataType: 'text',
type: "POST",
url: "/Home/Calculate",
success: function (data) {
$(".banner").html(data);
},
error: function () {
alert("Something went wrong in the controller");
}
});
return false;
})
View:
<div class="banner"></div>
<input name="input1" type="text">
<input name="input2" type="text">
<button id="calculate">Calculate Total</button>
Partial View:
<div>
Total:
<span id="totalValue">#ViewBag.Total</span>
</div>
EDIT: So just to clarify as to why I don't just pass the values as Ajax parameters is because in my actual view, the number of inputs is dynamically generated with JQuery. For example, I have a frame with 15 inputs, but users may choose to add additional frames - so in total there will be 30, 45, 60,... or more inputs. I'm not exactly sure how to handle Ajax parameters that way, so for each frame I loop 15 times, increment the input ID each time, and request the data that way. I've updated the code for the controller to better visualize what I'm saying.

Related

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

Not sure how to properly use a partial view

I read a lot of questions here on stacoverflow, but it is still not clear to me how should I use a partialview within a main view with an action method. What's probably wrong is my aproach in general. With what I have so far I am not sure how to continue with my code.
I will start with the main view :
#{
ViewBag.Title = "getRolesByYear";
}
</script>
<script type="text/javascript">
getRolesForYear(parseInt(#DateTime.Now.Year));
$(function () {
$('#years a').click(function () {
var year = $(this).text();
console.log(year);
getRolesForYear(parseInt(year));
});
})
//console.log(year);
function getRolesForYear(year) {
console.log(year);
$.ajax({
type: "POST",
url: '#Url.Action("getRolesByYear", "WorkRoles")',
dataType: "json",
data: {
year: year
},
success: successFunc,
error: errorFunc
});
function successFunc(data, status) {
console.log('x');
}
}
function errorFunc() {
alert('error');
}
}
</script>
<div id = "years" class="btn-group btn-group-justified timeline">
#DateTime.Now.Year
#DateTime.Now.AddYears(-1).Year
#DateTime.Now.AddYears(-2).Year
</div>
<div id"partial"></div>
In this view I have three buttons with different year for each button. On page load or on button click I make an ajax call to an action method with the an int year as a parameter.
This is a simplified version of my action method :
public ActionResult getRolesByYear(int year)
{
// a couple of queries here
var list = list of RoleViewModel objects;
return PartialView(list);
And here is the partialView :
#model IEnumerable<eksp.Models.RoleViewModel>
#foreach (var item in Model)
{
<div class="jumbotron">
<h2>item.Role.RoleName</h2>
<h1> item.Role.RoleDescription</h1>
<p class="lead">Focus start : item.Role.FocusStart</p>
<p>Focus end : item.Role.FocusStart </p>
</div>
}
Obviously, a lot of thins aren't clear to me. How can I use this partial view with the action method i have and the main view? Do I need a separate method for the partial view? Any tips?
Your ajax call will invoke the action method which returns the partial view result (markup generated by executing the partial view). I guess you simply need to use the response of the ajax call to update your DOM.
If you want to update the content of the div with id partial with the response, you can do that in the success event handler of your ajax call.
success : function(response)
{
$("#partial").html(response);
}
I would also recommend to call the getRolesForYear method on document ready event.
$(function () {
getRolesForYear(parseInt(#DateTime.Now.Year));
$('#years a').click(function () {
var year = $(this).text();
console.log(year);
getRolesForYear(parseInt(year));
});
})
Also, If your main view is also the result of action method getRolesByYear, you probably want to return the partial view result only on the ajax call, the other calls,you can return the partial view
public ActionResult getRolesByYear(int year)
{
var list = list of RoleViewModel objects;
if(Request.IsAjaxRequest())
{
return PartialView(list);
}
else
{
return View(list);
}
}
Here the same action method handles the request for main view and ajax call. It returns the same view for ajax call, but using PartialView call, so layout will be ignored. But If you have a specific view you want to return, you can do that as well.
if(Request.IsAjaxRequest())
{
return PartialView("_yearlyRoles",list);
}
One of the reasons I like using partial views for rendering data via Ajax calls. For example if I want to start searching in order to avoid the server call i Just use an ajax call to the controller which returns the search results through a partial view. In your example yoy need to load the results in partial div.
function successFunc(data, status) {
$("#partial").html(data);
}

How to refresh my Partial View after Ajax Post in MVC?

So basically I'm trying to show some Profile Data in my MVC Application.
Right now, everytime I click on a date on my Telerik Kendo Calendar, I can refresh the whole page and update the data I want.
However, instead of refreshing the whole I just want to refresh the partial views that shows only the data that updates after selecting the date.
Index.cshtml
<!--CODE-->
#Html.Partial("_WorkingTimeData")
<!--CODE-->
_WorkingTimeData.cshtml
var workedTime = ViewData["WorkedTimeToday"];
var hoursPerDay = ViewData["HoursPerDayContract"];
<p>You worked #workedTime hours</p>
<p>Hours Per Day (Contract) #hoursPerDay Hours</p>
Yes, right now I'm ViewDatas and it works.
This is the ajax code in Index.cshtml
$.ajax({ url: '/Profile/Index',
dataType: "json",
type: "POST",
data: JSON.stringify(10),
success: function(returl){
alert('It worked');
location.href=returl.Url;
},
error: function(jqXHR,responseText,textStatus){ alert(jqXHR.responseText) } });
Controller
[HttpPost]
public ActionResult Index(string number){
//THINGS TO DO
var redirectUrl = new UrlHelper(Request.RequestContext).Action("Index", "Profile");
return Json(new { Url = redirectUrl });
}
Well I'm very new to this, and I've been doing my research. However I still have some questions:
- Do I need to create a post method for _WorkingTimeData instead of Index like I have?
- Do I need to create a ViewModel for the Partial View?
Thanks
EDIT NUMBER 2 FOR VISHAL:
This didn't work at all, not even an alert, because, strangely, it doesn't recognise the calendar...
$("#calendar").kendoCalendar({
change : function() {
$.ajax({
url: "/Profile/WorkingTimeData",
type: "get"
}).done(function(data) {
$("#profile-timeline").html(data);
});
}});
It says $("#calendar").kendoCalendar is not a function (Telerik says that it's this way)
As for this, it reached the controller but didn't update anything:
function change() {
alert("Escolheste outro dia");
var calendar = $("#calendar").data("kendoCalendar");
var current = calendar.current();
alert(current);
$.ajax({
url: "/Profile/WorkingTimeData",
type: "get"
}).done(function(data) {
$("#profile-timeline").html(data);
});
}
I think it's because of the profile-timeline... It's a div in my view
Do I need to create a post method for _WorkingTimeData?
Yes, you need to create. But, Get would be fine too.
Do I need to create a ViewModel for the Partial View?
Not needed. If required you can create.
But, by looking at your partial view you are just using ViewData[""]. So, you need not to create any ViewModel.
Just create a method in Controller returning _WorkingTimeData PartialView.
And call that method by JQuery ajax on your DatePicker change event and replace the contents of the Div.
For example.
Controller
public PartialViewResult WorkingTimeData()
{
ViewData["WorkedTimeToday"]="NEW VALUE";
ViewData["HoursPerDayContract"] = "NEW VALUE";
return this.PartialView("_WorkingTimeData");
}
JavaScript
$("DATEPICKERELEMENT").change(function() {
$.ajax({
url: "/CONTROLLER/WorkingTimeData",
type: "get"
}).done(function(data) {
alert(data);
$("#divisionIdContainingPartialView").html(data);
}).fail(function() {
alert('error');
});
});
I wrote a post that details why you need to break the logic of thinking about partial views client-side. If you're interested you can find it here.
The TL;DR version is simply, all you have client-side is HTML. There's no knowledge about what was or was not rendered to the response via a partial view. As a result, the real question is "How do I change a portion of my HTML page based on an AJAX response?". In the simplest form, you simply select some element on the page and then alter its inner HTML. You can do that with some custom HTML created client-side or you can actually pass back an HTML document as your AJAX response and then insert that.

Display Success message on the same page when submit

I'm using Html.Beginform in view page and get the parameters using FormCollection to the controller i want to return the Success message on the same ViewPage as a result.i'm using following code,
public string InsertDetails(FormCollection collection)
{
string result = "Record Inserted Successfully!";
return result;
}
It shows the success message on the new page.How can i resolve this? what i have to return to get the Success message on the same page?
Personally, I'd pop the result string into the ViewBag.
public ActionResult InsertDetails(FormCollection collection)
{
//DO LOGIC TO INSERT DETAILS
ViewBag.result = "Record Inserted Successfully!";
return View();
}
Then on the web page:
<p>#ViewBag.result</p>
I have following Options.
1. Use Ajax Begin Form with AjaxOptions like below
#using (Ajax.BeginForm("ActionName", "ControllerName", new { area = "AreaName" }, new
AjaxOptions
{
HttpMethod = "POST",
OnSuccess = "alert('Success');" //This will execute once the Ajax call is finished.
}, null))
{
<input type="submit" name="nameSubmit" value="Submit" />
}
2. Use JQuery to Manually Setup the XHR Request
$.ajax({
url: "#Url.Action("ActionName", "ControllerName", new { area = "AreaName" });",
type: 'POST',
contentType: 'application/json; charset=utf-8',
data: JSON.stringify({param : Value})
})
.done(function () { alert('Success');}) //This will execute when you request is completed.
.fail(function () { })
My Suggestions
There are following disadvantages while using the FormCollection
Point - 1
In case FormCollection is being used...It will be mandatory to Type Cast the Primitive Type Values un-necessarily because while getting the entry of specific Index of the System.Collections.Specialized.NameValueCollection, value being returned is of type String. This situation will not come in case of Strongly Typed View-Models.
Issue - 2
When you submit the form and goes to Post Action Method, and View-Model as Parameter exists in the Action method, you have the provision to send back the Posted Values to you View. Otherwise, write the code again to send back via TempData/ViewData/ViewBag
Point - 3
We have Data Annotations that can be implemented in View Model or Custom Validations.
ASP.Net MVC simplifies model validatons using Data Annotation. Data Annotations are attributes thyat are applied over properties. We can create custom validation Attribute by inheriting the built-in Validation Attribute class.
Point - 4
Example you have the following HTML
<input type="text" name="textBox1" value="harsha" customAttr1 = "MyValue" />
Question : How can we access the value of customAttr1 from the above eg from inside the controller
Answer : When a form get posted only the name and value of elements are posted back to the server. You can also use Hidden Fields to post the Attributes to Post Action method.
Alternatives : Use a bit of jQuery to get the custom attribute values, and post that along with the form values to action method
Another option is to rather put what you got in your custom attributes in hidden controls
That's the reason, I would always prefer to use View-Models
we can do it on Form inside view
#using (Ajax.BeginForm("Action", "Controller", new AjaxOptions { HttpMethod = "POST", OnSuccess = "Showmessage" }))
[HttpPost]
public ActionResult Test(TestViewModel model)
{
return Json(new {isok=true, message="Your Message" });
}
function Showmessage(data)
{
$('#Element').html('Successfully Submitted');
}

Ajax not returning Partial View

I reallly have a simple set of code to bring back a set of data that is triggered off a drop down.
this is the script:
function () {
$('#ProviderID').change(function () {
$.ajax({
url: '/servicesDisplay/Index',
type: 'Get',
data: { id: $(this).attr('value') },
success: function (result) {
// The AJAX request succeeded and the result variable
// will contain the partial HTML returned by the action
// we inject it into the div:
$('#serLocations').html(result);
}
});
});
This is the controller:
public ActionResult Index(string id)
{
int prid = Int32.Parse(id.Substring(0, (id.Length-1)));
string mulitval = id.Substring((id.Length-1), 1).ToString();
System.Data.Objects.ObjectResult<getProviderServiceAddress_Result> proList = theEntities.getProviderServiceAddress(prid);
List<getProviderServiceAddress_Result> objList = proList.ToList();
SelectList providerList = new SelectList(objList, "AddressID","Address1");
//ViewBag.providerList = providerList;
return PartialView("servicesDisplay/Index", providerList);
}
This is the view:
#model OCS_CS.Models.servicesDisplay
<div>
#Html.DropDownList(model => model.ServiceAdderssID, (IEnumerable<SelectListItem>)model)
</div>
When the drop down passes the in the value. The apps does hit the controller. But it highlightes the drop down in a light red and the view never displays.
Try this short version which uses the jquery load method.
$(function(){
$('#ProviderID').change(function () {
$('#serLocations').load("#Url.Action("Index","ServicesDisplay")?id="
+$(this).val());
});
});
If you want to avoid caching of result, you may send a unique timestamp along with the querystring to avoid caching.
$('#serLocations').load("#Url.Action("Index","ServicesDisplay")?id="
+$(this).val()+"&t="+$.now());
You are doing a GET, thats no meaning to pass data to ajax, you may pass data for POST:
First, put the value at the URL:
function () {
$('#ProviderID').change(function () {
$.ajax({
url: '/servicesDisplay/Index/' + $(this).attr('value'),
type: 'Get',
success: function (result) {
// The AJAX request succeeded and the result variable
// will contain the partial HTML returned by the action
// we inject it into the div:
$('#serLocations').html(result);
}
});
});
Second, mark the method as GET
[HttpGet]
public ActionResult Index(string id)
Hopes this help you!
You have quite a few problems with your code. First the model defined for your view is:
#model OCS_CS.Models.servicesDisplay
but in your action your're invoking the call to this view by passing in a SelectList:
SelectList providerList = new SelectList(objList, "AddressID","Address1");
return PartialView("servicesDisplay/Index", providerList);
this is not going to fly because the models do not match by type. Seconds problem is you are casting this SelectList into an IEnumerable. This is also not going to work. You need to cast to SelectList:
#Html.DropDownList(model => model.ServiceAdderssID, (SelectList)model)
but again until you match the type of your model in your action with the model on your view none of this will work. I suggest you install Fiddler to help you determine what sort of error are you getting.

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