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How to send non-model data using a submit button (Razorpages)

I need to post a form but I also need to include the Id of the widget I want to remove from the model collection. Can I pass extra data with a submit, that is not part of the model?
I have generated html using a foreach loop. This displays the ID of a widget. The model for this page is a collection of widgets.
So the code used to display all widget Id's is as follows:
#foreach (var widget in widgets){
#i++; // Assume declared above or could use simple for loop ...
Widget #widget.Id
<input type="hidden" asp-for="Widgets[i].Id" /> // For binding the collection on POST
<br />
}
This displays:
Widget 1
Widget 2
Widget 3
...etc
I would like the user to have the option to remove Widget 2 from the list.
So the display will be something like this:
Widget 1 [x]
Widget 2 [x]
Widget 3 [x]
...etc
I would like to post the model back to the server and pass the Id of the widget... how do I do this?
If I use an input like below, how can I add the Id to it?
#foreach (var widget in widgets){
#i++; // Assume declared above or could use simple for loop ...
Widget #widget.Id
<input type="hidden" asp-for="Widgets[i].Id" /> // For binding the collection on POST
<input type="submit" asp-page-handler="RemoveWidget" name="x" />
<br />
}
I've thought about creating a global hidden input field and setting this field to the Id using javascript before the submit is sent, but I assume there is a better way than this?

In order to achieve your desired functionality, I am using ActionLink with a parameter:
#foreach (var widget in widgets){
Widget #widget.Id #Html.ActionLink("Delete", "Home", new { id = #widget.Id})<br />
}
And in your Controller:
public ActionResult Delete(int id)
{
//Get your widget ID here and do the deletion as required.
return View("Your View");
}
You can style your ActionLink as required like this:
#Html.ActionLink("Delete", "Home", new { id = #widget.Id},new { #style="your style goes here" });
EDIT:
You can use AJAX if you want to POST your data to your controller. Specifically in your case, I will show you an example:
#foreach (var widget in widgets){
Widget #widget.Id : <br />
}
In you AJAX:
function confirmDelete(event) {
var recordToDelete = $(event).attr("data-id"); //Get your current widget id here
if (confirm("Are you sure you want to delete this widget") == true) {
//Prepare our data
var json = {
id: recordToDelete
};
$.ajax({
url: '#Url.Action("Delete", "Home")',
type: "POST",
dataType: "json",
data: { "json": JSON.stringify(json) },
success: function (data) {
if(data == "success") {
alert("Successfully deleted selected widget");
location.reload();
}
},
error: function (data) {
alert("Could not delete selected widget. Please try again!");
},
});
}
};
And finally in your Controller:
//Delete a widget based on the ID that you get from your View
[HttpPost]
public JsonResult Delete(string json)
{
var serializer = new JavaScriptSerializer();
try
{
dynamic jsondata = serializer.Deserialize(json, typeof(object));
string id = jsondata["id"];
if(id != "")
{
int getid = Convert.ToInt32(id);
//Call your db or your logic to delete the file
DatabaseAccess data = new DatabaseAccess();
string result = data.DeleteFile(getid);
if(result.Equals("Success"))
{
return Json("success", JsonRequestBehavior.AllowGet);
}
else
{
return Json("fail", JsonRequestBehavior.AllowGet);
}
}
else
{
return Json("notfound", JsonRequestBehavior.AllowGet);
}
}
catch
{
return Json("dberror", JsonRequestBehavior.AllowGet);
}
}

asp.net mvc if else not working in view

This is my part of code from view called index
<div class="box-body">
#{ Html.RenderAction("_BlogsGrid",new {country=""});}
</div>
...
...
<script>
$("#SelectedCountry").change(function () {
var selectedCountry = $(this).val();
$.ajax({
url: '#Url.Action("_BlogsGrid","Blog")' + '?country=' + selectedCountry,
sucess: function(xhr, data) {
console.log('sucess');
},
error: function (err) {
console.log(err);
}
});
});
</script>
Here is the controller action code
public ActionResult _BlogsGrid(string country)
{
var blogs = _blogService.GetBlogWithCountryName(country).ToList();
var blogsList = BlogMapper.ToBlogIndex(blogs);
return PartialView(blogsList);
}
and here is _BlogsGrid view
#model Blog.BlogsList
<div class="pull-right">
#Html.DropDownListFor(m => m.SelectedCountry, new SelectList(Model.CountriesList), "Select a country", new { #class = "form-control" })
</div>
<br />
<br />
#if (Model.Blogs.Count == 0)
{
<div class="box-group">
<h4>Sorry we couldn't find any blog related to the country you asked for.</h4>
#Html.DisplayText("Hello world!")
</div>
}
else
{
<div class="box-group" id="accordion">
#foreach (var blog in Model.Blogs)
{
#*Some code*#
}
</div>
}
Thing is when i load it first time everything works fine, the controllers method gets hit and all the blogs get loaded this is how the view looks
but when I select a country from dropdown list and there are no blogs matching that country
it hits the if condition(putting a breakpoint in view I check if if condition is being executed or else condition is being executed, and it goes through if condition) in view (which is a partial view)
but the content of "if" is not loaded in the browser.
I am still getting same content as before. Any idea why my content is not being updated?
Update:
<div id="grid" class="box-body">
#{ Html.RenderAction("_BlogsGrid",new {country=""});}
</div>
<script>
$("#SelectedCountry").change(function () {
var selectedCountry = $(this).val();
$.ajax({
url: '#Url.Action("_BlogsGrid","Blog")' + '?country=' + selectedCountry,
sucess: function (data) {
$('#grid').html(data);
},
error: function (err) {
console.log(err);
}
});
});
</script>
in browser response
But still my div is not updating.

As others suggested, you're not updating your div content. That's way yo don't notice a change when the AJAX call is completed.
To ease things, in addition to .ajax(), jQuery provides the .load() method, which automatically fed the returned content into the matched elements. So your javascript could look like so:
<script>
$("#SelectedCountry").change(function () {
var selectedCountry = $(this).val();
$("div.box-body").load('#Url.Action("_BlogsGrid","Blog")', 'country=' + selectedCountry);
});
</script>

Your ajax success function does nothing with the server response. It just print success in the browser console.
You need to use the server response on the success function and replace the atual content of the page with the new content.
Your html response is the first argument from success function.
You can look at jquery documentantion for better undertanding (http://api.jquery.com/jquery.ajax/)
To replace the content of your page the success function should be like that:
sucess: function(data) {
$("div.box-body").html(data);
console.log('sucess');
},

When the page is created, Razor replace all # by their value to generated the whole HTML page. This is why in debug mode, your #Html.DisplayText is hit.
However, when you load the page, the if is taken into account, and if the condition is false, you don't see the inner HTML.
To update your DOM, you have to use the data parameter of the success ajax call. This parameter is automatically set by the return of your _BlogsGrid method.
You can see it by modifying your success callback. Note that the data parameter should be the first parameter
sucess: function(data) {
console.log(data);
},

You're not updating the data after the initial load. Your ajax call returns the html content of your partial view. You'd have to update it to the DOM manually. Give your container div an id.
<div id="blogs-grid" class="box-body">
#{ Html.RenderAction("_BlogsGrid",new {country=""});}
</div>
And then in your ajax success callback:
sucess: function(data) {
$('#blogs-grid').html(data);
},
Now whatever content your ajax returned will be bound to the blogs-grid div

Deleting a file from server on button click in ASP.NET MVC

I'm not well versed in this framework so I need some help here. In a view I want to add a link or a button on clicking which a certain file gets deleted from the server.
I've added this method to the controller:
[Authorize]
public ActionResult DeleteFile(string path)
{
if ((System.IO.File.Exists(path)))
{
try
{
System.IO.File.Delete(path);
}catch(Exception ex)
{
Debug.WriteLine("Deletion of file failed: " + ex.Message);
}
}
return View();
}
Seemed straightforward, though I'm not sure about the return View();. Now in the view, I need a form, because the path to the file that should be deleted needs to be posted to the controller, is that correct? This is what I got so far, mimicked from other code in the project:
#Html.BeginForm("DeleteFile", "Home", FormMethod.Post, new { id = "delete-attachment-form" })
{
#Html.Hidden("path", path)
}
path is a JavaScript variable containing the server path to the file that needs to be deleted. If I'm on the right track here, how do I add a button or a link to click on that will send the form?

Should just be able to add a submit button:
<input type="submit" name="submit" />

You should have a form and a button like this
#Html.BeginForm("Controller", "DeleteFile", new {Path= filePath},FormMethod.Post)
{
//Button
}
Or using Ajax and Jquery
var values = $(this).serialize();
$.ajax({
type: 'POST',
url: "url?path="+path.tostring(),
data: values ,
success: function(response) { //update view }
});

Inside your form you can add a button and then handle the button click in JavaScript.
#Html.BeginForm("DeleteFile", "Home", FormMethod.Post, new { id = "delete-attachment-form" })
{
#Html.Hidden("path", path)
<button id="delete-btn" type="button" class="btn btn-danger">
Delete
</button>
}
Then the <script type="text/javascript"> block:
$(function () {
$('#delete-btn').click(function () {
var query = $('#delete-attachment-form');
var form = query[0];
var toPost = query.serialize();
$.ajax({
url: form.action,
type: form.method,
data: toPost,
success: function (result) {
// display result
},
error: function () {
// handle error
}
})
});
});
Also, this is a good tutorial on deleting in ASP.NET MVC

Search method issue

I'm using MVC 5, C# and I'm trying to build a search filter that will filter through upon each key stroke. It works as so, but the textbox erases after submitting. Now this is probably not the best approach to it either. Is there a way to make so when it posts it doesn't erase the textbox, or better yet, is there a better alternative?
#using (Html.BeginForm("Index", "Directory", FormMethod.Post, new { id = "form" }))
{
<p>
Search Employee: <input type="text" name="userName" onkeyup="filterTerm(this.value);" />
</p>
}
<script>
function filterTerm(value) {
$("#form").submit();
event.preventDefault();
}
</script>

I agree with the comments on your question. Posting on every key stroke would be a frustrating user experience.
So, two answers, use ajax to perform the search (which will then keep the value since the whole page will not post) or have a submit button and name the input the same as the controller action parameter.
Controller code (used with your existing code):
public class DirectoryController : Controller
{
[HttpPost()]
public ActionResult Index(string userName)
{
// make the input argument match your form field name.
//TODO: Your search code here.
// Assuming you have a partial view for displaying results.
return PartialView("SearchResults");
}
}
View Code (to replace your code with Ajax):
<p>
Search Employee:#Html.TextBox("userName", new { id = "user-name-input" })
</p>
<div id="results-output"></div>
<script type="text/javascript">
$("#user-name-input").change(function(e) {
$.ajax({
url: '#Url.Action("Index", "Directory")'
, cache: false
, type: "post"
, data: {userName: $("#user-name-input").val() }
}).done(function (responseData) {
if (responseData != undefined && responseData != null) {
// make sure we got data back
$("#results-output").html(responseData);
} else {
console.log("No data returned.");
alert("An error occurred while loading data.");
} // end if/else
}).fail(function (data) {
console.log(data);
alert("BOOOM");
});
}
</script>

A better way is to ditch your Html.BeginForm (unless you actually need it for something else) and use a pure ajax method of getting the data.
So your modified html would be:
<p>
Search Employee:
<input type="text" name="userName" onkeyup="filterTerm(this.value);" />
</p>
<script>
function filterTerm(value) {
$.ajax({
url: '#Url.Action("Index", "Directory")',
data: {
searchTerm: value
},
cache: false,
success: function (result) {
//do something with your result,
//like replacing DOM elements
}
});
}
</script>
You also need to change the action that ajax will be calling (and I have no idea why you are calling the "Index" action).
public ActionResult Index(string searchTerm)
{
//lookup and do your filtering
//you have 2 options, return a partial view with your model
return PartialView(model);
//or return Json
return Json(model);
}
The best thing about this ajax is there is no posting and it's async, so you don't have to worry about losing your data.

How to create the confirm box in mvc controller?

I need to create the confirm box in mvc controller?. Using this 'yes' or 'no' value I need to perform the action in my controller. How we do that?
Sample code:
public ActionResult ActionName(passing value)
{
// some code
message box here
if (true)
{ true code}
else { else code}
}

You can do this with ActionLink
#Html.ActionLink(
"Delete",
"DeleteAction",
"Product",
new { confirm = true, other_parameter = "some_more_parameter" },
new { onclick = "return confirm('Do you really want to delete this product?')" })
If user confirm, then link parameter will pass to the controller action method.
public ActionResult DeleteAction(bool confirm, string other_parameter)
{
// if user confirm to delete then this action will fire
// and you can pass true value. If not, then it is already not confirmed.
return View();
}
Update
You can not show message box in controller side. But you can do this like following
public ActionResult ActionName(passing value)
{
// some code
message box here
if (true){ ViewBag.Status = true }
else { ViewBag.Status = false}
return View();
}
And view
<script type="text/javascript">
function() {
var status = '#ViewBag.Status';
if (status) {
alert("success");
} else {
alert("error");
}
}
</script>
But these all codes are not elegant way. This is solution of your scenerio.

Yes, you can do this with #Html.ActionLink as AliRıza Adıyahşi has commented.
Subscribe to the onclick event of the #Html.ActionLink
Here is the implementation:
#Html.ActionLink("Click here","ActionName","ControllerName",new { #onclick="return Submit();"})
And in javascript write the confirm box.
<script type="text/javascript">
function Submit() {
if (confirm("Are you sure you want to submit ?")) {
return true;
} else {
return false;
}
}
</script>
Edit
Try like this:
<script type="text/javascript">
function Submit() {
if (confirm("Are you sure you want to submit ?")) {
document.getElementById('anchortag').href += "?isTrue=true";
} else {
document.getElementById('anchortag').href += "?isTrue=false";
}
return true;
}
</script>
#Html.ActionLink("Submit", "Somemethod", "Home", new { #onclick = "return Submit();", id = "anchortag" })
Now in your controller do some operations based on the isTrue querystring
public ActionResult Somemethod(bool isTrue)
{
if (isTrue)
{
//do something
}
else
{
//do something
}
return View();
}

You dont create confirm box in a Controller, but yes in a View, using JQuery Dialog.
The Controller is already inside the server, so you don't have user interactions there.
Your View, in the other hand, is the place where the user will choose options, type information, click on buttons etc...
You can intercept the button click, to show that dialog, and only submit the post when the option "Yes" gets clicked.
JQuery Dialog requires jquery.js, jquery-ui.js, jquery.ui.dialog.js scripts referenced in your page.
Example:
$(function(){
$("#buttonID").click(function(event) {
event.preventDefault();
$('<div title="Confirm Box"></div>').dialog({
open: function (event, ui) {
$(this).html("Yes or No question?");
},
close: function () {
$(this).remove();
},
resizable: false,
height: 140,
modal: true,
buttons: {
'Yes': function () {
$(this).dialog('close');
$.post('url/theValueYouWantToPass');
},
'No': function () {
$(this).dialog('close');
$.post('url/theOtherValueYouWantToPAss');
}
}
});
});
});

I can confirm that AliRıza Adıyahşi's solution works well.
You can also customize the the message. In my case we're using MVC and Razor, so I could do this:
<td>
#Html.ActionLink("Delete",
"DeleteTag", new { id = t.IDTag },
new { onclick = "return confirm('Do you really want to delete the tag " + #t.Tag + "?')" })
</td>
Which showed a dialog with a specific record named in it. Might also be possible to give the confirm dialog a title, haven't tried that yet.

<a href="#Url.Action("DeleteBlog", new {id = #post.PostId})" class="btn btn-sm btn-danger" onclick="return confirm ('Are you sure want to delete blog?');">
<i class="glyphicon glyphicon-remove"></i> Delete