Develop Reference

ASP Core Razor Syntax #for -> multiple submitbuttons with diffrent inputs?

i am trying to create a ASP Core Application with Razorpages.
Everything is working fine so far, but now i'm stuck with this problem:
I want to create a form with multiple Buttons based on a Objectarray. Each Button has its own Name and should call the same OnPost method. So far so good. I struggle with posting the correct Object with the form.
Here is some Code...
Test.cshtml :
#page
#using APP.Models
#model TestModel
#{
ViewData["Title"] = "Test";
Layout = "~/Pages/Shared/_Layout.cshtml";
var bereiche = Bereich.getBereiche();
}
<div class="grid">
<h1 class="center-text">#ViewData["Title"]</h1>
<form method="post" class="center">
<div class="form-group">
<label asp-for="Model" class="col-form-label"></label>
<div class="button-group-vertical">
#for (var i = 0; i < bereiche.Count; i++)
{
<input type="hidden" asp-for="Model" value="#bereiche[i]" />
<button class="btn btn-info btn-md button-group-vertical-item">#bereiche[i].name</button>
}
</div>
</div>
</form>
</div>
Bereich.cs in namespace Model
public enum Art
{
Mitte, Beladen, Inspection, Kette
}
public class Bereich
{
public string name { get; set; }
public Art art { get; set; }
public static List<Bereich> getBereiche()
{
var bereiche = new List<Bereich>
{
new Bereich() { name="Mitte", art = Art.Mitte},
new Bereich(){name= "Beladen",art = Art.Beladen },
new Bereich(){name = "Qualitätskontrolle",art = Art.Inspection},
new Bereich(){name ="Kette",art= Art.Kette}
};
return bereiche;
}
}
Test.cshtml.cs :
public class TestModel : PageModel
{
[DisplayName("Bereich")]
[BindProperty]
public Bereich Model { get; set; }
public void OnGet()
{
}
public IActionResult OnPost()
{
return Page(); // BREAKPOINT HERE -> MODEL always "art=Mitte", "name=null" :/
}
}
Does anyone have a clue what i am doin wrong ?

In order to post an object back, you could use one form per object, with named fields corrosponding to your object property names.
Try this instead:
#for (var i = 0; i < bereiche.Count; i++)
{
<form method="post" class="center">
<input name="art" type="hidden" value="#bereiche[i].art" />
<button name="name" value="#bereiche[i].name" class="btn btn-info">#bereiche[i].name</button>
</form>
}
And also if you want your button to hold a value, you need to put the value in a value tag like i did in the example.

Dynamic MVC Model Server side validation

I have the following view:
#model dynamic
<form class="form-horizontal" id="formDynamicItem" action="/DynamicItem/SaveItem" method="post">
#Html.AntiForgeryToken()
<div class="col-xs-12 buttonBar">
<button type="submit" value="Save" name="submitButton" class="btn">Save</button>
<button type="submit" value="Cancel" name="submitButton" class="btn">Cancel</button>
</div>
<div class="col-lg-6">
<div class="ibox ">
<div class="ibox-content">
#{
foreach (var obj in Model)
{
var kvpObj = (KeyValuePair<string, object>)obj;
var entityProp = (EntityAttributeProperties)kvpObj.Value;
<div class="form-group">
#if (entityProp.IsHiddenField)
{
<input type="hidden" class="form-control" data-val="true" id="#kvpObj.Key" name="#kvpObj.Key" value="#entityProp.Value" />
}
else if (entityProp.IsFormField)
{
var isReadOnly = entityProp.IsReadonly ? "readonly" : "";
IHtmlString validationRules = Html.Raw(string.Empty);
if (entityProp.ValidationRules != null)
{
validationRules = entityProp.ValidationRules;
}
#Html.Label(entityProp.Name, new { #class = labelClass })
<div class="#controlClass">
#switch (#entityProp.Type)
{
//... many cases
default:
<input type="text" class="form-control" id="#kvpObj.Key" name="#kvpObj.Key" value="#entityProp.Value" #isReadOnly #validationRules />
break;
}
</div>
}
</div>
}
}
</div>
</div>
</div>
</form>
#section Scripts {
<script>
$("#formDynamicItem").validate();
</script>
}
And in the controller I get my values using FormCollection:
public ActionResult SaveItem(FormCollection form)
{
...
newValue = typeConverter.ConvertFromString(form[entityAttribute.Name]);
...
}
}
My question is the following:
How can I establish Server-side validation on such dynamic model? Can I use FormCollection somehow? Possibly build dynamic view model somehow? If anyone has experience in this please consider giving a suggestion(answer).
Update: Making Detail page with ViewModel insted of dynamic model
So, After much refactoring I appear to be again stuck with server-side validation:
So now I have this ViewModel:
public class DynamicItemViewModel
{
public Guid Id { get; set; }
public List<EntityAttributeProperties> Properties { get; set; }
}
this detail page:
#model ExactDistillation.Models.DynamicItem.DynamicItemViewModel
<div class="wrapper wrapper-content animated fadeInRight">
<div class="row">
#using (Html.BeginForm("SaveItem", "DynamicItem", FormMethod.Post, new { #class = "form-horizontal", #id = "formDynamicItem" }))
{
#Html.AntiForgeryToken()
#Html.HiddenFor(x => x.Id)
<div class="col-xs-12 buttonBar">
<button type="submit" value="Save" name="submitButton" class="btn btn-primary pull-right">Save</button>
<button type="submit" value="Cancel" name="submitButton" class="btn btn-default pull-right cancel">Cancel</button>
</div>
<div class="col-lg-6">
<div class="ibox float-e-margins">
<div class="ibox-title text-webwonders">
<h5>Item</h5>
</div>
<div class="ibox-content">
#{
for (int i = 0; i < Model.Properties.Count; i++)
{
#Html.EditorFor(m => Model.Properties[i], "EntityAttributeProperties", "Properties[" + i + "]")
}
}
</div>
</div>
</div>
}
</div>
</div>
And this is how I define EntityAttributeProperties page:
#model EntityAttributeProperties
<div class="form-group">
#if (Model.IsHiddenField)
{
#Html.HiddenFor(x => x.Value)
}
else if (Model.IsFormField)
{
#Html.Label(Model.Name, new { #class = "col-sm-5 col-md-4 col-lg-3" })
<div class="col-sm-7 col-md-8 col-lg-9">
#switch (Model.Type)
{
--- Many cases
default:
#Html.DynamicTextBoxFor(m => m.Value, null, Model.IsReadonly, Model.ValidationRules)
break;
}
</div>
}
</div>
EntityAttributesProperties looks the following way:
public class EntityAttributeProperties
{
public string Name { get; set; }
public string DisplayName { get; set; }
public object Value { get; set; }
public EntityAttributeDataTypeEnum Type { get; set; }
public short Order { get; set; }
public bool IsFormField { get; set; }
public bool IsReadonly { get; set; }
public bool IsHiddenField { get; set; }
public Dictionary<string,object> ValidationRules { get; set; }
}
So, I am trying to make server-side validation for Model, but I am stuck, because I don't find any elegant solution to my problem, just solutions in which I have to do a lot of hardcoding (which I don't like).
Here is how I receive the form Submit:
public ActionResult SaveItem(DynamicItemViewModel model)
{
List<EntityAttributeExtendedView> entityAttributes = GetItemEntityAttributes();
DataObject dataObject = _dbContext.DataObjectCollection.FirstOrDefault(x => x.Id == model.Id);
if (dataObject != null)
{
JObject json = JObject.Parse(dataObject.Value);
dynamic dynJson = JsonConvert.DeserializeObject(dataObject.Value);
// Possibly loop through all entity attributes and separately make a custom validation ?
// Or somehow create custom Model State for validation ?
}
return View("Detail", model);
}
I will appreciate any suggestion on how to approach the problem with server side validation.
Thanks.

FormCollection is a very raw form of data and cannot be validated easily. I'd suggest you should refactor your view to be able to use ViewModels, else you will have a hard time working with the Data.
I cannot show you the full way but give you some hints:
Create a single View Model class for the View which contains a list of Items (of type EntityAttributeProperties). Let's call it MainViewModel.
Pass this View Model to the view rather then the Dictionary
In your view, use #Html.EditoFor(x => x.Items) to generate the correct HTML. ASP.NET MVC will use the Editor Templates for EntityAttributeProperties type
This is a good moment to create a new view EntityAttributeProperties.cshtml in your View folders EditorTemplates sub-folder
within this item view, you can do all your entityProp.Type switches, but be careful with ID generation, always use #Html.IdFor(...) etc. instead of generating own IDs to keep type safe with your View Model
After some tweaks, your Post Action should be able to receive your view model of Type MainViewModel. If everything went good, the Item's will be filled, even if you used different Controls (hidden fields, text fields, drop-downs...) to populate the Values
From my perspective, only this MVC-safe approach will lead to success in this case

I'm adding another Answer because the Question changed heavily.
A good approach is to use the IValidatableObject Interface. So you add this Interface to your EntityAttributeProperties class and have to override the Method Validate. for simple validation like required fields, you use so called validation Attributes.
Your EntityAttributeProperties class would be decorated like this:
public class EntityAttributeProperties : IValidatableObject
{
public string Name { get; set; }
[Required]
public object Value { get; set; }
...
public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
{
var results = new List<ValidationResult>();
if (... /* some condition, e.g. specific EntityAttributeDataTypeEnum */)
{
// Do some validation
// some other random test
if (.../* something not right... */)
{
results.Add(new ValidationResult("your input was not valid!"));
}
}
return results;
}
}
You might need to also make your DynamicItemViewModel and IValidatableObject and loop through the Items, but sometimes MVC is smart enough to validate sub-items automatically, so you might need this:
public class DynamicItemViewModel : IValidatableObject
{
...
public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
{
return Items.SelectMany(x => x.Validate(validationContext));
}
}
OK now in your Controller, you basically need to check your ModelState. The automatically generated ModelState Property contains all errors.

Model passed to Partial to View

Been searching around but couldn't find a direct solution to what I'm trying to achieve.
I've tried to include as much as needed but it's a very large project so hopefully you'll get the gist.
Overview:
I have a view model that has several lists of objects within it. I am using two partial views for control over each of the list of objects, one for gathering the list of objects (which is held in a session), and the other for adding a list of said object into the list.
Update:
As per comment - what I am looking to do is as follows - in the Index, fill out the existingIp model info, which is displayed through the addToListPartialView, then it will post to the ListPartialView to update the list through the session, handled backend in the controller, which will in turn display on the Index - the question ultimately is, how do I achieve this?
Problem:
The issue I'm having is once I've added an object, through a partial view, to the object list, another partial view, how do I then pass this back to the main view?
Code:
Controller
public ActionResult AddExistingIp([Bind(Include = "Subnet, Cidr, Mask")]ExistingIp existingIp)
{
if(Session["pa_ipv4Session"] != null)
{
pa_ipv4 pa_ipv4 = (pa_ipv4)Session["pa_ipv4Session"];
if(pa_ipv4.ExistingIps == null)
{
pa_ipv4.ExistingIps = new List<ExistingIp>();
}
pa_ipv4.ExistingIps.Add(existingIp);
ViewBag.pa_ipv4 = pa_ipv4.ExistingIps;
return View("ExistingIpView", ViewBag.pa_ipv4);
}
else
{
pa_ipv4 pa_ipv4 = new pa_ipv4();
Session["pa_ipv4Session"] = pa_ipv4;
pa_ipv4.ExistingIps = new List<ExistingIp>();
pa_ipv4.ExistingIps.Add(existingIp);
ViewBag.pa_ipv4 = pa_ipv4.ExistingIps;
return View("ExistingIpView", ViewBag.pa_ipv4);
}
Index:
#model ViewModel
<div id="ExistingIpList">
#{Html.RenderPartial("ExistingIpView");}
</div>
<div id="addExisting">
#{Html.RenderPartial("AddExistingIp");}
</div>
List Partial
#model IEnumerable<ExistingIp>
#if (Model != null)
{
foreach (var ei in Model)
{
<div class="ui-grid-c ui-responsive">
<div class="ui-block-a">
<span>#ei.Subnet</span>
</div>
<div class="ui-block-b">
<span>#ei.Cidr</span>
</div>
<div class="ui-block-c">
<span>#ei.Mask</span>
</div>
<div class="ui-block-d">
#ei.Id
Delete
</div>
</div>
}
}
Add to list partial:
#using (Html.BeginForm("AddExistingIp", "PA_IPV4"))
{
<div class="ui-grid-c ui-responsive">
<div class="ui-block-a">
<span>
#Html.EditorFor(m => m.Subnet)
#Html.ValidationMessageFor(m => m.Subnet)
</span>
</div>
<div class="ui-block-b">
<span>
#Html.EditorFor(m => m.Cidr)
#Html.ValidationMessageFor(m => m.Cidr)
</span>
</div>
<div class="ui-block-c">
<span>
#Html.EditorFor(m => m.Mask)
#Html.ValidationMessageFor(m => m.Mask)
</span>
</div>
<div class="ui-block-d">
<span>
#Html.EditorFor(m => m.Id)
#Html.ValidationMessageFor(m => m.Id)
</span>
</div>
</div>
<div data-role="main" class="ui-content">
<div data-role="controlgroup" data-type="horizontal">
<input type="submit" id="addExistingIp" cssclass="ui-btn ui-corner-all ui-shadow" value="Add" />
</div>
</div>
}
ViewModel:
public Contact ContactDetails { get; set; }
[Required]
public bool ExistingAddress { get; set; }
public List<ExistingIp> ExistingIps { get; set; }
[Required]
[DataType(DataType.MultilineText)]
public string ExistingNotes { get; set; }

You can modify the AddExistingIp to just store the data. And to make a RedirectToAction Index. There you will take the data from Session and pass it to the Model.
[HttpPost]
public ActionResult AddExistingIp([Bind(Include = "Subnet, Cidr, Mask")]ExistingIp existingIp)
{
if(Session["pa_ipv4Session"] != null)
{
pa_ipv4 pa_ipv4 = (pa_ipv4)Session["pa_ipv4Session"];
if(pa_ipv4.ExistingIps == null)
{
pa_ipv4.ExistingIps = new List<ExistingIp>();
}
pa_ipv4.ExistingIps.Add(existingIp);
}
else
{
pa_ipv4 pa_ipv4 = new pa_ipv4();
Session["pa_ipv4Session"] = pa_ipv4;
pa_ipv4.ExistingIps = new List<ExistingIp>();
pa_ipv4.ExistingIps.Add(existingIp);
}
return RedirectToAction("Index");
}
The Index Action will look similar with this, where you take data from Session and use it in your Model
public ActionResult Index()
{
var viewModel = new ViewModel();
// take data from Session
pa_ipv4 pa_ipv4 = Session["pa_ipv4Session"] as (pa_ipv4);
// some verification
// add the list from Session to model
viewModel.ExistingIps = pa_ipv4.ExistingIps;
return View(viewModel);
}
Also, I think your Index View you should at ExistingIpView you should pass the Model to display.
#model ViewModel
<div id="ExistingIpList">
#{Html.RenderPartial("ExistingIpView", Model.ExistingIps);}
</div>
<div id="addExisting">
#{Html.RenderPartial("AddExistingIp");}
</div>

Passing multiple Collections of data from View to Controller (ASP.NET MVC 5)

In a View i have the next structure ( control of Subject*s for each *Group):
#using (Html.BeginForm())
{
#Html.AntiForgeryToken()
<div class="form-horizontal">
#for (int i = 0; i < ViewBag.AllGroups.Count; i++)
{
<h4>#ViewBag.AllGroups[i].Code</h4>
<select id="e-#i" multiple="multiple">
#foreach (Subject subject in ViewBag.AllSubjects)
{
<option value="#subject.Name">#subject.Name</option>
}
</select>
}
<input type="submit" value="Generate" class="btn btn-default" />
</div>
}
The question is that how can I retreive this data (I want to receive (1)list of Groups and and I want to get a (2)list of all selected Subjects for each group in my list(1)) in my Controller?
Thank you in advance.

Recommended way is to use strongly typed View Model Object
public class GroupViewModel
{
public string Code { get;set; }
public List<Subject> AllSubjects { get; set; }
}
Pass List as the Model to the Razor view in the controller.
return new View(new List<GroupViewModel>()); // populated one.
Use this list in the View.
#model IList<GroupViewModel>
#for (int i = 0; i < Model.Count; i++)
{
<h4>Model[i].Code</h4>
<select id="e-#i" multiple="multiple">
#foreach (Subject subject in Model[i].AllSubjects)
{
<option value="#subject.Name">#subject.Name</option>
}
</select>
}

There is nothing especial to deal with this situation, except that you have missed the tag name of the select element.
To be exact, all html elements such as select you have used here, should have a name not id (id="e-#i") and all elements are serialized based their names and sent to server. On the other side, at server-side, you should get the posted values which are in a csv formatted (due to multiple ability added you have added to select element)

Solved my problem by simplifying the task. What i had to to: I created new ViewModel for this thing. I replaced tag <select></select> with #Html.ListBoxFor(m => m.Subjects, Model.SubjectItems). I had to create a SubjectItems list in my ViewModel.
Here's the code (Sorry for tons of code: I just want to make everything clear):
My View:
#using System
#using System.Linq
#using TimeTable.GenericRepository
#model TimeTable.Models.GroupViewModel
#{
//it's better to move the next line to a Controller later
ViewBag.GroupId = new SelectList(new GroupRepository().Get().ToList(), "Id", "Code", Model.GroupId);
ViewBag.Title = "Index";
Layout = "~/Views/Shared/_LayoutBootstrap.cshtml";
}
<h2>Index</h2>
<hr />
#using (Html.BeginForm())
{
#Html.AntiForgeryToken()
<div class="form-horizontal">
#Html.ValidationSummary(true)
<div class="form-group">
#Html.LabelFor(model => model.GroupId, "Group is: ", new { #class = "control-label col-md-2" })
<div class="col-md-10">
#Html.DropDownList("GroupId", String.Empty)
#Html.ValidationMessageFor(model => model.GroupId)
</div>
</div>
#Html.ListBoxFor(m => m.Subjects, Model.SubjectItems, new { #id = "e", #style = "width:80%; " })
<br /><br />
<input type="submit" value="Generate" class="btn btn-default" />
</div>
}
#* ReSharper disable once Razor.SectionNotResolved *#
#section Scripts {
#Styles.Render("~/Content/select2")
#Scripts.Render("~/bundles/select2")
<script type="text/javascript">
$(function () { $("#e").select2(); });
</script>
}
My Controller:
public ActionResult Generate()
{
return View(new GroupViewModel());
}
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Generate(GroupViewModel gvm)
{
var subjects= gvm.Subjects; // <== selected subjects are here
return View();
}
My Model:
public class GroupViewModel
{
public int GroupId{ get; set; }
public Group Group {
get { return new GroupRepository().GetById(GroupId); }
}
public object Subjects { get; set; }
public IEnumerable<SelectListItem> SubjectItems
{
get
{
var items = new SelectList(new SubjectRepository().Get().ToList(), "Id", "Name");
return items;
}
}
}
P.S. Select2 is a custom replacement for selectBoxes, it's not necessary, but I like it: http://ivaynberg.github.io/select2/

MVC 3 Editor Template with Dynamic Drop Down

How do I get the drop down to display as part of my editor template?
So I have a Users entity and a Roles entity. The Roles are passed to the view as a SelectList and User as, well, a User. The SelectList becomes a drop down with the correct ID selected and everything thanks to this sample.
I'm trying to get an all-in-one nicely bundled EditorTemplate for my entities using MVC 3 so that I can just call EditorForModel and get the fields laid out nicely with a drop down added whenever I have a foreign key for things like Roles, in this particular instance.
My EditorTemlates\User.cshtml (dynamically generating the layout based on ViewData):
<table style="width: 100%;">
#{
int i = 0;
int numOfColumns = 3;
foreach (var prop in ViewData.ModelMetadata.Properties
.Where(pm => pm.ShowForDisplay && !ViewData.TemplateInfo.Visited(pm)))
{
if (prop.HideSurroundingHtml)
{
#Html.Display(prop.PropertyName)
}
else
{
if (i % numOfColumns == 0)
{
#Html.Raw("<tr>");
}
<td class="editor-label">
#Html.Label(prop.PropertyName)
</td>
<td class="editor-field">
#Html.Editor(prop.PropertyName)
<span class="error">#Html.ValidationMessage(prop.PropertyName,"*")</span>
</td>
if (i % numOfColumns == numOfColumns - 1)
{
#Html.Raw("</tr>");
}
i++;
}
}
}
</table>
On the View I'm then binding the SelectList seperately, and I want to do it as part of the template.
My Model:
public class SecurityEditModel
{
[ScaffoldColumn(false)]
public SelectList roleList { get; set; }
public User currentUser { get; set; }
}
My Controller:
public ViewResult Edit(int id)
{
User user = repository.Users.FirstOrDefault(c => c.ID == id);
var viewModel = new SecurityEditModel
{
currentUser = user,
roleList = new SelectList(repository.Roles.Where(r => r.Enabled == true).ToList(), "ID", "RoleName")
};
return View(viewModel);
}
My View:
#model Nina.WebUI.Models.SecurityEditModel
#{
ViewBag.Title = "Edit";
Layout = "~/Views/Shared/_Layout.cshtml";
}
<h2>Edit</h2>
#using(Html.BeginForm("Edit", "Security"))
{
#Html.EditorFor(m => m.currentUser)
<table style="width: 100%;">
<tr>
<td class="editor-label">
User Role:
</td>
<td class="editor-field">
<!-- I want to move this to the EditorTemplate -->
#Html.DropDownListFor(model => model.currentUser.RoleID, Model.roleList)
</td>
</tr>
</table>
<div class="editor-row">
<div class="editor-label">
</div>
<div class="editor-field">
</div>
</div>
<div class="editor-row"> </div>
<div style="text-align: center;">
<input type="submit" value="Save"/>
<input type="button" value="Cancel" onclick="location.href='#Url.Action("List", "Clients")'"/>
</div>
}
Hopefully that's clear enough, let me know if you could use more clarification. Thanks in advance!

Since you need access to the SelectList you can either create an editor template bound to SecurityEditModel or you can pass the SelectList in ViewData. Personally I would go with the strongly typed approach.