I'm attempting to implement a simple client side validation in a web app I'm working on, and the actual validation message is working. However, when I correct the incorrect input and the control loses focus, the validation message doesn't clear and the invalid class remains on the control. Here's the relevant view code
#model Project.CommentViewModel
#using (Html.BeginForm())
{
#Html.ValidationSummary(true);
<div class="Comment">
<div class="CommentInfo">
Post New Comment:
</div>
<div class="CommentText">
<div class="commentEdit ">
#Html.TextAreaFor(x => x.CommentText, new { #class = "NewCommentTextBox" })
#Html.ValidationMessageFor(x => x.CommentText)
</div>
#Html.HiddenFor(x => x.ProjectID)
</div>
</div>
}
And the view model attribute
[StringLength(50)]
public string CommentText { get; set; }
As I mentioned earlier, once the comment gets too long and the control loses focus, the error message comes up as expected. When the error is fixed however, the error message doesn't disappear and the control stays red. My _Layout page has the relevant script files included in the right order, and my config file has the appSetting variables set correctly. Any idea what's wrong or where I should be looking for the problem at? Thanks very much for any advice.
Resolved the problem. A Telerik grid that was present elsewhere on the page seems to have been conflicting with the validation somehow and broke it. Manually registering the jquery validation scripts with the grid resolved the issue.
#(Html.Telerik().ScriptRegistrar().DefaultGroup(group =>
group.Add("jquery.validate.js").Add("jquery.validate.unobtrusive.js")))
I think they may have resolved this particular issue with a newer version of the Telerik library.
Related
I have a View MyView.cshtml with the following content:
#using MyProject.ViewModels
#model MyProject.ViewModels.MyViewViewModel
<form asp-action="Test" method="Post">
<component type="typeof(MyProject.Views.Home.Test)" render-mode="ServerPrerendered" />
<input type="submit" value="send"/>
</form>
And I have the Razor Component Test.razor with the following content (with Blazor Syntax):
#page "/Test"
<div class="form-group top-buffer #Visible">
<div class="row">
<div class="col-2">
<label asp-for="TestName" class="control-label"></label>
</div>
<div class="col-3">
<input asp-for="TestName" class="form-control" />
<span asp-validation-for="TestName" class="text-danger"></span>
</div>
</div>
</div>
<button #onclick="Show">Show</button>
#code {
public string Visible { get; set; } = "hidden";
protected async Task Show()
{
Visible = "";
}
}
The Class MyViewViewModel would look like this:
namespace MyProject.ViewModels
{
public class MyViewViewModel
{
[Display(Name = "Test Name:")]
public string TestName { get; set; }
}
}
Works all pretty fine so far. However I now want to use this component as part of a Web form which will be sent to the controller after submission. That's why I need to access and change properties of my ViewModel 'MyViewViewModel'. Unfortunately I did not find any answer in the internet on how to do that. I can't use #model MyProject.ViewModels.MyViewViewModel like in the view because this will give me a compilation error. I wonder if I need to use #inject, but if yes, I don't know how...
(parts are used from this example: https://jonhilton.net/use-blazor-in-existing-app/)
When you mix Blazor in a Razor Page, you can do the following:
Render a Razor Component
Interact with a Razor Component
Pass a Razor Component values
Please keep in mind that you are dealing with two different life-cycles. So if you do work inside of a Razor Component, the component will update but not effect the Razor Page it is hosted inside of. So mixing Razor Components and Pages with forms would be difficult.
More specifically to the OP. To pass data from your ViewModel to the component you may use the following method.
#using MyProject.ViewModels
#model MyProject.ViewModels.MyViewViewModel
<form asp-action="Test" method="Post">
<component type="typeof(MyProject.Views.Home.Test)"
render-mode="ServerPrerendered"
param-Name="#Model.TestName"/>
<input type="submit" value="send"/>
</form>
Test.razor
<h3>HelloWorld</h3>
Hello #Name
#code {
[Parameter]
public string Name { get; set; } = "undefined";
}
About life cycles
Basically when you have a button in Blazor, it will trigger an event which causes the component to re-render. You could imagine it like an iframe, or update-panel. When you have a button in a Razor page, it does a HTTP call round trip and reloads the page entirely. There is no event system in place to tell Blazor to invoke an HTTP call round trip to refresh the Razor page's content and vise versa. You can only one-way data-bind from Razor pages to Blazor, think write-only, and only when the page loads.
To hopefully add to the info. With a ASP.Net Core MVC project host Blazor webassembly, I was trying to pass a viewmodel into a razor component using this code in my view cshtml file:
<component Type="typeof(Leave)" render-mode="WebAssembly" model="new { model = (MyViewModel)#Model})"/>
But it would fail to render the razor component if I tried to access data in the viewmodel from the razor component with an Object not set exception. I think it was accessing the data before the view model has been initialized. Maybe if I set a default value this could avoided?
I found by using this instead I was able to get it working.
#(await Html.RenderComponentAsync<Leave>(RenderMode.WebAssembly,new { model = (MyViewModel)#Model}))
Edit
Seems you also need to register the viewModel class in the services in the Blazor WASM project in the Program.cs file.
builder.Services.AddScoped(sp => new HttpClient {BaseAddress = new Uri(builder.HostEnvironment.BaseAddress) });
builder.Services.AddScoped<MyViewModel,MyViewModel>(); // <= add this line
await builder.Build().RunAsync();`
Without that I would get an error saying the property could not be found.
Hopefully this saves someone else some time :-)
I'm using DataAnnotations to validate my input fields on a MVC3 application. I'm using regular expressions validations.
I get the validation messages on the UI for IE8 & IE9.
But I notice the difference when I hit the Save button even after the client side validation has failed.
IE9 keeps me on the client side.
On IE8 however, the control goes to the controller action, and I have to have a controller side TryValidateModel so that the validation errors out.
Does anyone know why IE8 is doing a server round trip?
Edit:
Adding the code. This goes into the cshtml.
#using (Html.BeginForm("Person", "Account", FormMethod.Post))
{
<span class="resultError" id="resultError">
#Html.ValidationMessageFor(model => model.Name, "Name should not contain special characters")
</span>
<table>
<tr>
<td class="editor-label">Name:
</td>
<td class="editor-field">#Html.EditorFor(model => model.Name)
</td>
</tr>
</table>
<input type="submit" name="btnKey" value="Save" />
}
This is the partial class using DataAnnotation. The Person class is driven by EF. So I have to create a metadata class to do the validation.
[MetadataType(typeof(personMetadata))]
public partial class person: EntityObject
{
public class personMetadata
{
[Required]
[RegularExpression(#"[A-Za-z0-9]+")]
public object Name { get; set; }
}
}
Edit: Adding the javascript files that are referenced.
"~/Scripts/jquery.validate.min.js"
"~/Scripts/jquery.validate.unobtrusive.min.js"
In my case, which is a lot like yours, I found that updating jquery.validate.js was the way to go. There is a reported bug on version 1.8.0 of jquery validation about IE 7, 8 and 9.
After getting the latest version everything started to work.
I have put together a small example here just to replicate the problem.
I have a strongly typed partial view _Name.cshtml:
#model ValidationInPartial.ViewModels.MyViewModel
<h2>#ViewBag.Message</h2>
<fieldset>
<legend>Name</legend>
<div class="editor-label">
#Html.LabelFor(model => model.MyName)
</div>
<div class="editor-field">
#Html.EditorFor(model => model.MyName)
#Html.ValidationMessageFor(model => model.MyName)
</div>
Reload Name
<p>
<input type="submit" value="Create" />
</p>
</fieldset>
<script type="text/javascript">
$(document).ready(function () {
$("#reload").click(function () {
$("#divName").load("Home/NameReload");
});
});
</script>
that is initially loaded and displayed inside the main Index.cshtml
<div id="divForm">
#using (Html.BeginForm()) {
<div id="divName">
#Html.Partial("_Name")
</div>
}
</div>
The field MyName is required and validation is implemented through Required attribute in MyViewModel
namespace ValidationInPartial.ViewModels
{
public class MyViewModel
{
[Required(ErrorMessage = "Please enter a Name.")]
public string MyName { get; set; }
}
}
After the page is loaded the first time, if you click the Create button leaving the field empty the validation message "Please enter a Name." shows beside the field and the field itself turns pink, which is the expected behaviour.
Now by clicking the "Reload Name" link, which makes an ajax call (jquery.load(...)), the partial is reloaded, here is controller code:
public PartialViewResult NameReload()
{
MyViewModel myViewModel = new MyViewModel();
ViewBag.Message = "Name Reloaded";
return PartialView("_Name", myViewModel);
}
This time if you click the Create button leaving the field empty the validation message does not appear beside the field, although the field turns pink.
It turns out that when reloading the partial the #Html.ValidationMessageFor doesn't render the validation message as the first time.
Here is the jquery files I use
<script src="#Url.Content("~/Scripts/jquery-1.5.1.min.js")" type="text/javascript"></script>
<script src="#Url.Content("~/Scripts/jquery.validate.js")" type="text/javascript"></script>
<script src="#Url.Content("~/Scripts/jquery.validate.unobtrusive.min.js")" type="text/javascript"></script>
<script src="#Url.Content("~/Scripts/jquery.unobtrusive-ajax.min.js")" type="text/javascript"></script>
I wonder if this is a bug in the way the Razor engine renders the #Html.ValidationMessageFor or is that a problem with jquery?
Any idea why this happens?
I have also read somewhere that the ajax call looses all the scripts for the page, in fact I have to keep any javascript code inside the partial so that they can be rendered and used again.
In the meantime I found a workaround which is to manually render in the partial what was supposed to be rendered by #Html.ValidationMessageFor which is:
<span class="field-validation-valid" data-valmsg-replace="true" data-valmsg-for="MyName"></span>
However this workaround means that if we change the type of validation or just the validation message inside the Required attribute in the ViewModel, we need to modify this hard-coded piece of html in the view.
#NickBork has a great answer here. The key is that ASP.NET's MVC rendering engine does not output the validation script if it doesn't think that there is a form. The example given hacks it buy putting in a form and then selection an inner section of HTML from was was returned, essentially throwing the outer wrapper of the form away.
There is another method so that you can just get your view:
ViewContext.FormContext = new FormContext();
With this method, there won't actually be FORM code output, but the validation markup will be there.
Thanks,
John
Validation markup (span tags, custom field attributes, etc) are not rendered unless your fields are contained within a FORM. The validation plugin itself does not work with elements outside of a form.
When ASP.NET renders your Partial View the controls are not within a form and thus do not get the elements rendered.
When you load you're partial content you'll need to parse the HTML using a jQuery selector.
In my sample below I have a TBODY on the parent View page that contains rows. When I need to add additional rows, I make a call to a View which had a form, table, tbody and collection of rows.
$.ajax({
type: "POST",
url: "/controller/action",
data: ({Your: 'dataHere'}),
dataType: "html",
success:
function(response){
$('tbody').append($('tbody',$(response)).html());
//The validation plugin can't bind to the same form twice.
//We need to remove existing validators
$('form').removeData("validator");
//Refresh the validators
$.validator.unobtrusive.parse(document);
},
error:
function(){
alert('An error occured while attempting to add the new content');
}
});
Note that I'm using a jQuery selector to select the rows that are inside of the View/PartialView that are loaded in by using AJAX:
$('tbody',$(response)).html()
The rest of the wrapper just appends the rows from the AJAX View/PartialView to the calling parents tbody:
$('tbody').append($('tbody',$(response)).html());
A couple other notes, after the validator plugin has been run on a form, it can not be called again without re-adding it (see jquery.validate.unobtrusive not working with dynamic injected elements)
To fix this, I first call the following method to remove all validators:
$('form').removeData("validator");
$("form").removeData("unobtrusiveValidation");
I then refresh the validators using the following:
$.validator.unobtrusive.parse(document);
I can't remember where I found the solution. The reason is because you are loading a PartialView into a View that has already been parsed by the jquery.validator.unobtrusive library. You need to re-parse the unobtrusive library
function ReparseValidation(){
jQuery.validator.unobtrusive.parse("#yourcontainer");
}
I'm new to MVC, so I wasn't sure what the best approach would be here.
I have a view model that contains several collections like this:
public class MainViewModel{
public List<AViewModel> A { get; set; }
public List<BViewModel> B {get; set; }
...}
I'm using Steve Sanderson's approach here to dynamically add items to a collection, and it's working fine as long as the child items are editable on the main view.
The problem I'm having is returning a read only list with an edit link that will open the details to edit in a popup dialog.
Since these items may be newly added, I can't use the ID property to return a partial view from the controller. It seems like I'll have to render the editors in a hidden div like this:
<div class="AEditorRow">
#using (Html.BeginCollectionItem("A"))
{
#Html.DisplayFor(l => l.ID)
#Html.DisplayFor(l => l.Name)
#Html.DisplayFor(l => l.Code)
edit <text>|</text>
delete
<div class="ADetails" style="display: none">
#using (Html.BeginForm("EditA", "Controller"))
{<fieldset>
<legend>Location</legend>
#Html.HiddenFor(model => model.ID)
<div class="editor-label">
#Html.LabelFor(model => model.Code)
</div>
Does anyone know of a better way to do this?
After working on this issue for a while now I was able to find a walk-through that worked for me.
http://jarrettmeyer.com/post/2995732471/nested-collection-models-in-asp-net-mvc-3
I think this is the most applicable technique for accomplishing dynamically added nested collection objects for MVC3. Most of the other suggestions I've found were meant for MVC2 or MVC1, and it seems that every iteration of MVC the best way to accomplish this changes slightly.
Hopefully this works for you.
I have the same question. Now looking for solution.
Seems like this resources can help:
http://www.joe-stevens.com/2011/06/06/editing-and-binding-nested-lists-with-asp-net-mvc-2/
http://blog.stevensanderson.com/2010/01/28/editing-a-variable-length-list-aspnet-mvc-2-style/
Model binding nested collections in ASP.NET MVC
Good evening everyone I have a question regarding validation of drop-down list values. I have a view that is bound to a view model type called ReservationData.
This object contains a property CustomerVehicles of type List<VehicleData>. VehicleData has two int properties VehicleMakeId and VehicleModelId.
On my view I am trying to loop over the number of items in the CustomerVehicles collection and displaying two dropdowns for each, a vehicle make dropdown and a vehicle model dropdown using DropDownListFor.
When I try to submit and validate I do not see any validation errors displayed on the screen.
Just in case you are wondering I have added a ValidationMessageFor for each dropdown as well. I am not sure if this is an issue with the structure of my view model and its complexity and how the controls need to be named or how the ids need to be set. Any help would be greatly appreciated.
Here is the code for the looping over the collection:
#for (var i = 0; i < Model.CustomerVehicles.Count(); i++)
{
var vehicleNumber = i + 1;
<div class="vehicle-selection-wrapper">
<div class="content-container">
<h3>
Vehicle #vehicleNumber</h3>
<img class="vehicle-image" alt="manufacturer image" src="#Url.Content("~/Content/images/default-vehicle.gif")" /><br />
#Html.LabelFor(m => m.CustomerVehicles[i].VehicleMakeId)
#Html.DropDownListFor(m => m.CustomerVehicles[i].VehicleMakeId
, new SelectList(Model.VehicleMakes, "Id", "Name")
, #UIDisplay.Dropdown_DefaultOption, new { #class = "long-field" })<br />
#Html.ValidationMessageFor(m => m.CustomerVehicles[i].VehicleMakeId)<br />
#Html.LabelFor(m => m.CustomerVehicles[i].VehicleModelId)
#Html.DropDownListFor(m => m.CustomerVehicles[i].VehicleModelId
, new SelectList(new List<CWR.Domain.VehicleModel>(), "Id", "Name")
, #UIDisplay.Dropdown_DefaultOption, new { #class = "long-field" })
#Html.ValidationMessageFor(m => m.CustomerVehicles[i].VehicleModelId)
</div>
</div>
}
Ok so I also noticed that in the generated HTML the selects that are generated are missing the HTML5 data-val attributes that are associated to elements to handle validation. Here is the generated HTML
<select class="long-field" id="CustomerVehicles_0__VehicleMakeId" name="CustomerVehicles[0].VehicleMakeId"><option value="">-- Select --</option>
</select><br />
<span class="field-validation-valid" data-valmsg- for="CustomerVehicles[0].VehicleMakeId" data-valmsg-replace="true"></span><br />
<label for="CustomerVehicles_0__VehicleModelId">Model</label>
<select class="long-field" id="CustomerVehicles_0__VehicleModelId" name="CustomerVehicles[0].VehicleModelId"><option value="">-- Select --</option>
</select>
<span class="field-validation-valid" data-valmsg-for="CustomerVehicles[0].VehicleModelId" data-valmsg-replace="true"></span>
Additionally in my VehicleData class the VehicleMakeId and VehicleModelId properties are decorated with a Required attribute.
UPDATE:
Ok so I was testing and noticed that if I keep my code identical except I swap the Html.DropdownListFor calls with Html.TextboxFor calls then the validation works. What could be causing this? Could it be a framework bug with the unobtrusive validation?
UPDATE: Contains Fix
So after posting this same question on the ASP.NET Forums, I was able to get a solution. In the post you will be able to see that there is a bug in the unobtrusive validation framework and how it handles validation of dropdownlists. The user counsellorben does a good job in explaining the problem as well as a solution (including sample code) that will assist others in avoiding this issue in the future, or at least until Microsoft builds in a fix in to the framework.
Thank you everyone for your assistance.
I too have come across this obviously massive oversight regarding client side validation with dropdownlists in MVC 3 and the best solution I can offer is to put the missing HMTL attributes in yourself.
In your view model create a property like this.
public Dictionary<string, object> CustomerVechicleAttributes
{
get
{
Dictionary<string, object> d = new Dictionary<string, object>();
d.Add("data-val", "true");
d.Add("data-val-required", "Please select a Vechicle.");
return d;
}
}
Then in your code, enter
#Html.DropDownListFor(m => m.CustomerVehicles[i].VehicleMakeId
, new SelectList(Model.VehicleMakes, "Id", "Name")
, #UIDisplay.Dropdown_DefaultOption,
**Model.CustomerVechicleAttributes** })
Just add the Model.CustomerVechicleAttributes as htmlAttributes to your dropdownlist.
This will inject the necessary attributes that are missing. You will of course need to add any other attributes you may need like your class attribute.
Hope this helps.
This is the simpliest way I found to do it, just adding data-val-*-* attributes in HtmlAttributes of DropDownListFor, inside the view. The following method works with RemoteValidation too, if you do not need remote validation, simply remove the elements containing data-val-remote-*:
#Html.DropDownListFor(m => m.yourlistID, (IEnumerable<SelectListItem>)ViewBag.YourListID, String.Empty,
new Dictionary<string, object>() { { "data-val", "true" },
{ "data-val-remote-url", "/Validation/yourremoteval" },
{ "data-val-remote-type", "POST" }, { "data-val-remote-additionalfield", "youradditionalfieldtovalidate" } })
I hope it may help. Best Regards!
you should try to add data annotations on your view model properties first so you could see the validation messages.
you might find what you need here
http://msdn.microsoft.com/en-us/library/system.componentmodel.dataannotations.aspx
or create custom ones if needed.
what exactly do you need to validate?
I had exactly the same problem with the field getting correctly validated in TextBoxFor but not in DropDownListFor.
#Html.DropDownListFor(m => m.PaymentTO.CreditCardType, Model.CreditCardTypeList, "Select Card Type", new { style = "width:150px;" })
Since I had another DropDownListFor working on the same page, I knew that it wasn’t a generic DropDownListFor problem. I also have a complex model and parent object PaymentTO wasn’t initialized. When I set viewTO.PaymentTO = new PaymentTO(); in the Controller, the validation for the DropDownListFor started to work. So there is probably a problem with DropDownListFor, but the fix can be as simple as initializing the object in the controller.