This very well may end up being a very silly question in a way but basically I have this "form" in a model that gets attached to my View as the form but I haven't been able to actually pass any data do it from the View. It only has two properties: an Id property and a String property. I've been trying to fill the String property with text from a hidden text box on the page with no luck.
Form code:
public class AllocateListForm
{
public int Id { get; set; }
public virtual string HiddenText { get; set; }
}
Relevant View code:
<% using (Html.BeginForm("SaveExit", "User", new { }, FormMethod.Post, new { id = "selectExitPoints" })) { %>
<fieldset>
<input type="hidden" id="HiddenText" />
</fieldset>
<% } %>
There is JQuery behind the scenes that fills HiddenText with text and I can assure you that it is filling. There is also JQuery behind the scenes that performs an Ajax submission and I can promise you that code works as it is used elsewhere in the application without a problem. When I perform the action that submits the form to the server and I go to my controller code that this points to, I have a breakpoint set so I can go into the console and check if the HiddenText field on the form has any data it is null. Can anybody point me in the right direction?
If you assign the input's name to be "HiddenText" the model binder should pick it up. I'm assuming that your controller action accepts an AllocateListForm as a parameter.
<input type="hidden" name="HiddenText" id="HiddenText" />
You can also use Html Helpers like so:
#Html.HiddenFor(model => model.HiddenText, new { id = "HiddenText" })
EDIT: Add an AllocateListForm as a property of your main model and then change the helper to be #Html.HiddenFor(model => model.MyAllocateListForm.HiddenText)
This should do the trick, if you want to do it the Razor-way.
#Html.HiddenFor(model => model.HiddenText);
I understand that I can use #Html.HiddenFor(m => m.parameter) and when the form is submitted, that parameter will be passed to the controller. My model has many properties.
Is there a shorter way of passing the entire model at once to the controller or must I do it one by one each time?
The model will be passed to the controller in its entirety, but the values of properties that are not bound by input or hidden fields will be lost.
You have to either bind the properties in the form on the client-side, or re-fetch the entity on the server-side.
You seem to be asking for something like #Html.HiddenFor(m => m.Model), and that is not possible. Sorry
One thing to keep in mind, if you have tons of hidden fields, you may be sending more data to the view than you really need. Consider employing view models
For anyone else who looks at this you can do a #Html.EditorForModel() in a hidden div. You'd also have to use #Html.EditorFor(model => model.ObjectProperty) for each object property of the model.
<div hidden="hidden">
#Html.EditorForModel()
#Html.EditorFor(model => model.ObjectProperty)
#Html.EditorFor(model => model.ListOfObjectsProperty)
</div>
The entire model will be posted if you are using a FORM element. Your elements using the Model obviously need to be inside the form element
You can also POST the form yourself say by using JQuery
See this other stack issue for that : jQuery AJAX submit form
Have a close look at the anwser by "Alfrekjv"
This is already built in. Consider this model:
public class MyModel
{
public string PropertyA { get; set; }
public string parameter { get; set; }
}
and now consider this action:
[HttpPost]
public ActionResult PostSomeData(MyModel model)
{
}
MVC will leverage the FormCollection and fill in the MyModel class where it can. If you don't have the PropertyA in the form then it will be null. But since you have an input for the parameter property it will be filled in.
You can check only the properties you want:
if (this.ModelState.IsValidField("Name"))
{
// .....
}
instead of:
if (this.ModelState.IsValid)
{
// .....
}
#using (Ajax.BeginForm("my_function", "my_controller", new AjaxOptions { InsertionMode = InsertionMode.Replace }, mymodel))
Basically I have a form that I am dynamically adding objects to. I am doing this with AJAX so can just initialise the object and return it with JSON. Each new object has a unique GUID assigned to it so we can identify each object in the model collection when it is passed back into the action.
However, I need to support non JavaScript so am trying to write a solution that will post back the model and add or remove the given object from the model. There can be any number of these new objects on the model so I need to pass back several things to find out which object to delete before returning the model back to the view. This could be either
a) The GUID for the object the user has deleted.
b) The button that has been clicked to identify which object to delete.
The problem is that the partial view is generic and I would like to keep it that way so I'm trying to pass the identifying GUID back with the input button on each partial view but don't know how. I can easily do this with JavaScript because I just remove the created AJAX object from the page before posting it when the user clicks the remove link but can't figure out how to do it with a submit. Basically I want to do something like this:
#using (Project.Namespace.Infrastructure.Helpers.HtmlPrefixScopeExtensions.HtmlFieldPrefixScope _scope = Html.BeginCollectionItem())
{
<ul class="ulMedicationsControl">
#Html.ActionLink("Remove This Object", "RemoveObject", null)
#Html.Input("RemoveObject", "Remove This Object", new { Prefix = _scope.Prefix, objectGUID = IdentifyingGUID })
#Html.HiddenFor(m => m.IdentifyingGUID);
<li class="liQuestion">
#Html.MandatoryLabelFor(m => m.myField)
#Html.TextBoxFor(m => m.myField)
</li>
</ul>
<div id="#(_scope.Prefix).ajaxPlaceholder"></div>
}
In the controller:
[ActionName("FormName")]
[AcceptParameter(Name = "RemoveObject", Value = "Remove This Object")]
public ActionResult RemoveObject(MyParentModel model, string Prefix, string objectGUID)
{
Guid ID = new Guid(objectGUID);
foreach (ObjectModel object in model.objects){
if (object.IdentifyingGUID == ID)
{
model.objects.Remove(object);
break;
}
}
return View(model);
}
Any help I would really appreciate as I simple can't figure out how to do this!
EDIT
Also just to add the prefix attribute simply identifies where in the form the object sits. This will be needed for me to find which object list to go through and remove the object from as there may be several lists in different placed in the model.
An HTML input only passes "name=value" when a form post occurs so that's all you have to work with. With <input type=submit> you're further limited by the fact that the button's value is its caption (i.e. "myControl=Click Me!" is posted), so you can't stick anything programmatically meaningful in the value.
Method 1: So you're left with encoding all the information you need into the input's name - an approach that works fine, but you'll have to have to go digging into the controller action method's FormCollection parameter rather than relying on model binding. For example:
<input name="delete$#(_scope.Prefix)$#objectGUID" type="submit" value="Delete me" />
Better, have a helper class that encapsulates the string format with a ToString override and has Parse/TryParse/etc static methods, which could be used like this:
<input name="#(new DeleteToken{Prefix=_scope.Prefix, objectGUID=IdentifyingGUID})" type="submit" value="Delete me" />
In your action method:
[HttpPost]
public ActionResult Foo(FormCollection formData)
{
var deleteTokens = DeleteToken.ParseAll(formData.AllKeys);
foreach (var token in deleteTokens)
{
//...do the deletion
}
}
Method 2: An alternative approach is to group each item into its own <form> (bear in mind you can't nest forms) - so when the submit happens, only its surrounding form is posted in which you can stash hidden inputs with the necessary data. e.g.
<ul class="ulMedicationsControl">
<form ... >
<!-- hidden field and submit button and whatever else here -->
...
</form>
</ul>
Caution: This question is over nine years old!
Your best option is to search for newer questions, or to search the answers below looking for your specific version of MVC, as many answers here are obsolete now.
If you do find an answer that works for your version, please make sure the answer contains the version of MVC you are using.
(The original question starts below)
This seems a bit bizarre to me, but as far as I can tell, this is how you do it.
I have a collection of objects, and I want users to select one or more of them. This says to me "form with checkboxes." My objects don't have any concept of "selected" (they're rudimentary POCO's formed by deserializing a wcf call). So, I do the following:
public class SampleObject{
public Guid Id {get;set;}
public string Name {get;set;}
}
In the view:
<%
using (Html.BeginForm())
{
%>
<%foreach (var o in ViewData.Model) {%>
<%=Html.CheckBox(o.Id)%> <%= o.Name %>
<%}%>
<input type="submit" value="Submit" />
<%}%>
And, in the controller, this is the only way I can see to figure out what objects the user checked:
public ActionResult ThisLooksWeird(FormCollection result)
{
var winnars = from x in result.AllKeys
where result[x] != "false"
select x;
// yadda
}
Its freaky in the first place, and secondly, for those items the user checked, the FormCollection lists its value as "true false" rather than just true.
Obviously, I'm missing something. I think this is built with the idea in mind that the objects in the collection that are acted upon within the html form are updated using UpdateModel() or through a ModelBinder.
But my objects aren't set up for this; does that mean that this is the only way? Is there another way to do it?
Html.CheckBox is doing something weird - if you view source on the resulting page, you'll see there's an <input type="hidden" /> being generated alongside each checkbox, which explains the "true false" values you're seeing for each form element.
Try this, which definitely works on ASP.NET MVC Beta because I've just tried it.
Put this in the view instead of using Html.CheckBox():
<% using (Html.BeginForm("ShowData", "Home")) { %>
<% foreach (var o in ViewData.Model) { %>
<input type="checkbox" name="selectedObjects" value="<%=o.Id%>">
<%= o.Name %>
<%}%>
<input type="submit" value="Submit" />
<%}%>
Your checkboxes are all called selectedObjects, and the value of each checkbox is the GUID of the corresponding object.
Then post to the following controller action (or something similar that does something useful instead of Response.Write())
public ActionResult ShowData(Guid[] selectedObjects) {
foreach (Guid guid in selectedObjects) {
Response.Write(guid.ToString());
}
Response.End();
return (new EmptyResult());
}
This example will just write the GUIDs of the boxes you checked; ASP.NET MVC maps the GUID values of the selected checkboxes into the Guid[] selectedObjects parameter for you, and even parses the strings from the Request.Form collection into instantied GUID objects, which I think is rather nice.
HtmlHelper adds an hidden input to notify the controller about Unchecked status.
So to have the correct checked status:
bool bChecked = form[key].Contains("true");
In case you're wondering WHY they put a hidden field in with the same name as the checkbox the reason is as follows :
Comment from the sourcecode MVCBetaSource\MVC\src\MvcFutures\Mvc\ButtonsAndLinkExtensions.cs
Render an additional <input
type="hidden".../> for checkboxes.
This addresses scenarios where
unchecked checkboxes are not sent in
the request. Sending a hidden input
makes it possible to know that the
checkbox was present on the page when
the request was submitted.
I guess behind the scenes they need to know this for binding to parameters on the controller action methods. You could then have a tri-state boolean I suppose (bound to a nullable bool parameter). I've not tried it but I'm hoping thats what they did.
You should also use <label for="checkbox1">Checkbox 1</label> because then people can click on the label text as well as the checkbox itself. Its also easier to style and at least in IE it will be highlighted when you tab through the page's controls.
<%= Html.CheckBox("cbNewColors", true) %><label for="cbNewColors">New colors</label>
This is not just a 'oh I could do it' thing. Its a significant user experience enhancement. Even if not all users know they can click on the label many will.
I'm surprised none of these answers used the built in MVC features for this.
I wrote a blog post about this here, which even actually links the labels to the checkbox. I used the EditorTemplate folder to accomplish this in a clean and modular way.
You will simply end up with a new file in the EditorTemplate folder that looks like this:
#model SampleObject
#Html.CheckBoxFor(m => m.IsChecked)
#Html.HiddenFor(m => m.Id)
#Html.LabelFor(m => m.IsChecked, Model.Id)
in your actual view, there will be no need to loop this, simply 1 line of code:
#Html.EditorFor(x => ViewData.Model)
Visit my blog post for more details.
Here's what I've been doing.
View:
<input type="checkbox" name="applyChanges" />
Controller:
var checkBox = Request.Form["applyChanges"];
if (checkBox == "on")
{
...
}
I found the Html.* helper methods not so useful in some cases, and that I was better off doing it in plain old HTML. This being one of them, the other one that comes to mind is radio buttons.
Edit: this is on Preview 5, obviously YMMV between versions.
They appear to be opting to read the first value only, so this is "true" when the checkbox is checked, and "false" when only the hidden value is included. This is easily fetched with code like this:
model.Property = collection["ElementId"].ToLower().StartsWith("true");
#Dylan Beattie Great Find!!! I Thank you much. To expand even further, this technique also works perfect with the View Model approach. MVC is so cool, it's smart enough to bind an array of Guids to a property by the same name of the Model object bound to the View. Example:
ViewModel:
public class SampleViewModel
{
public IList<SampleObject> SampleObjectList { get; set; }
public Guid[] SelectedObjectIds { get; set; }
public class SampleObject
{
public Guid Id { get; set; }
public string Name { get; set; }
}
}
View:
<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">
<h2>Sample View</h2>
<table>
<thead>
<tr>
<th>Checked</th>
<th>Object Name</th>
</tr>
</thead>
<% using (Html.BeginForm()) %>
<%{%>
<tbody>
<% foreach (var item in Model.SampleObjectList)
{ %>
<tr>
<td><input type="checkbox" name="SelectedObjectIds" value="<%= item.Id%>" /></td>
<td><%= Html.Encode(item.Name)%></td>
</tr>
<% } %>
</tbody>
</table>
<input type="submit" value="Submit" />
<%}%>
Controller:
[AcceptVerbs(HttpVerbs.Get)]
public ActionResult SampleView(Guid id)
{
//Object to pass any input objects to the View Model Builder
BuilderIO viewModelBuilderInput = new BuilderIO();
//The View Model Builder is a conglomerate of repositories and methods used to Construct a View Model out of Business Objects
SampleViewModel viewModel = sampleViewModelBuilder.Build(viewModelBuilderInput);
return View("SampleView", viewModel);
}
[AcceptVerbs(HttpVerbs.Post)]
public ActionResult SampleView(SampleViewModel viewModel)
{
// The array of Guids successfully bound to the SelectedObjectIds property of the View Model!
return View();
}
Anyone familiar with the View Model philosophy will rejoice, this works like a Champ!
I'd also like to point out that you can name each checkbox a different name, and have that name part of the actionresults parameters.
Example,
View:
<%= Html.CheckBox("Rs232CheckBox", false, new { #id = "rs232" })%>RS-232
<%= Html.CheckBox("Rs422CheckBox", false, new { #id = "rs422" })%>RS-422
Controller:
public ActionResults MyAction(bool Rs232CheckBox, bool Rs422CheckBox) {
...
}
The values from the view are passed to the action since the names are the same.
I know this solution isn't ideal for your project, but I thought I'd throw the idea out there.
<input type = "checkbox" name = "checkbox1" /> <label> Check to say hi.</label>
From the Controller:
[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Index(FormCollection fc)
{
var s = fc["checkbox1"];
if (s == "on")
{
string x = "Hi";
}
}
This issue is happening in the release 1.0 as well. Html.Checkbox() causes another hidden field to be added with the same name/id as of your original checkbox. And as I was trying loading up a checkbox array using document.GetElemtentsByName(), you can guess how things were getting messed up. It's a bizarre.
From what I can gather, the model doesn't want to guess whether checked = true or false, I got around this by setting a value attribute on the checkbox element with jQuery before submitting the form like this:
$('input[type="checkbox"]').each(function () {
$(this).attr('value', $(this).is(':checked'));
});
This way, you don't need a hidden element just to store the value of the checkbox.
I know that this question was written when MVC3 wasn't out, but for anyone who comes to this question and are using MVC3, you may want the "correct" way to do this.
While I think that doing the whole
Contains("true");
thing is great and clean, and works on all MVC versions, the problem is that it doesn't take culture into account (as if it really matters in the case of a bool).
The "correct" way to figure out the value of a bool, at least in MVC3, is to use the ValueProvider.
var value = (bool)ValueProvider.GetValue("key").ConvertTo(typeof(bool));
I do this in one of my client's sites when I edit permissions:
var allPermissionsBase = Request.Params.AllKeys.Where(x => x.Contains("permission_")).ToList();
var allPermissions = new List<KeyValuePair<int, bool>>();
foreach (var key in allPermissionsBase)
{
// Try to parse the key as int
int keyAsInt;
int.TryParse(key.Replace("permission_", ""), out keyAsInt);
// Try to get the value as bool
var value = (bool)ValueProvider.GetValue(key).ConvertTo(typeof(bool));
}
Now, the beauty of this is you can use this with just about any simple type, and it will even be correct based on the Culture (think money, decimals, etc).
The ValueProvider is what is used when you form your Actions like this:
public ActionResult UpdatePermissions(bool permission_1, bool permission_2)
but when you are trying to dynamically build these lists and check the values, you will never know the Id at compile time, so you have to process them on the fly.
The easiest way to do is so...
You set the name and value.
<input type="checkbox" name="selectedProducts" value="#item.ProductId" />#item.Name
Then on submitting grab the values of checkboxes and save in an int array.
then the appropriate LinQ Function. That's it..
[HttpPost]
public ActionResult Checkbox(int[] selectedObjects)
{
var selected = from x in selectedObjects
from y in db
where y.ObjectId == x
select y;
return View(selected);
}
Same as nautic20's answer, just simply use MVC default model binding checkbox list with same name as a collection property of string/int/enum in ViewModel. That is it.
But one issue need to point out. In each checkbox component, you should not put "Id" in it which will affect MVC model binding.
Following code will work for model binding:
<% foreach (var item in Model.SampleObjectList)
{ %>
<tr>
<td><input type="checkbox" name="SelectedObjectIds" value="<%= item.Id%>" /></td>
<td><%= Html.Encode(item.Name)%></td>
</tr>
<% } %>
Following codes will not binding to model (difference here is it assigned id for each checkbox)
<% foreach (var item in Model.SampleObjectList)
{ %>
<tr>
<td><input type="checkbox" name="SelectedObjectIds" id="[some unique key]" value="<%= item.Id%>" /></td>
<td><%= Html.Encode(item.Name)%></td>
</tr>
<% } %>
this is what i did to loose the double values when using the Html.CheckBox(...
Replace("true,false","true").Split(',')
with 4 boxes checked, unchecked, unchecked, checked it turns
true,false,false,false,true,false
into
true,false,false,true.
just what i needed
How about something like this?
bool isChecked = false;
if (Boolean.TryParse(Request.Form.GetValues(”chkHuman”)[0], out isChecked) == false)
ModelState.AddModelError(”chkHuman”, “Nice try.”);
When using the checkbox HtmlHelper, I much prefer to work with the posted checkbox form data as an array. I don't really know why, I know the other methods work, but I think I just prefer to treat comma separated strings as an array as much as possible.
So doing a 'checked' or true test would be:
//looking for [true],[false]
bool isChecked = form.GetValues(key).Contains("true");
Doing a false check would be:
//looking for [false],[false] or [false]
bool isNotChecked = !form.GetValues(key).Contains("true");
The main difference is to use GetValues as this returns as an array.
Just do this on $(document).ready :
$('input:hidden').each(function(el) {
var that = $(this)[0];
if(that.id.length < 1 ) {
console.log(that.id);
that.parentElement.removeChild(that);
}
});
My solution is:
<input type="checkbox" id="IsNew-checkbox" checked="checked" />
<input type="hidden" id="IsNew" name="IsNew" value="true" />
<script language="javascript" type="text/javascript" >
$('#IsNew-checkbox').click(function () {
if ($('#IsNew-checkbox').is(':checked')) {
$('#IsNew').val('true');
} else {
$('#IsNew').val('false');
}
});
</script>
More you can find here:
http://www.blog.mieten.pl/2010/12/asp-net-mvc-custom-checkbox-as-solution-of-string-was-not-recognized-as-a-valid-boolean/
I had nearly the same Problem but the return Value of my Controller was blocked with other Values.
Found a simple Solution but it seems a bit rough.
Try to type Viewbag. in your Controller and now you give it a name like Viewbag.Checkbool
Now switch to the View and try this #Viewbag.Checkbool with this you will get the value out of the Controller.
My Controller Parameters look like this:
public ActionResult Anzeigen(int productid = 90, bool islive = true)
and my Checkbox will update like this:
<input id="isLive" type="checkbox" checked="#ViewBag.Value" ONCLICK="window.location.href = '/MixCategory/Anzeigen?isLive=' + isLive.checked.toString()" />
Using #mmacaulay , I came up with this for bool:
// MVC Work around for checkboxes.
bool active = (Request.Form["active"] == "on");
If checked
active = true
If unchecked
active = false