MVC Binding Data - asp.net-mvc

I have a MVC Project.
I have questions in a database that I want my users to answer. I have them in the database because they need to be able to be dynamic. The user needs to submit an answer for each question. So when the view displays, it shows the question and a textbox for each question.
What would the best way to go about doing this as I do not want to hard code in the question like #Html.textBox("Question1") etc.
Question 1 [__textbox1___]
Question 2 [__textbox2___]
... etc.

I'd probably have a ViewModel that contains a collection of a custom QuestionResponder type.
IEnumerable<IQuestionResponder> Questions{get;set;}
public interface IQuestionResponder{
Guid QuestionId{get;set;}
string Question{get;set;}
string Answer{get;set;}
}
Then you can create the display items you require for your new view model.
#for(var i = 0; i <= questionList .Count; i++)
{
#Model.Questions.ToList()[i].Question
#Html.TextBoxFor(m => m.Questions.ToList()[i].Answer)
}
Alternartively you can create an EditorTemplate to avoid looping in your view:
Insdie ~/Views/Shared/EditorTemplates/ add a new view called QuestionResponder (the name of your custom class).
Inside that template you can then add:
#model MyApp.Models.QuestionResponder
<div>
#Html.DisplayFor(m => m.Question)
#Html.TextBoxFor(m => m.Answer)
</div>
While you'll then call from your original view:
#Html.EditorFor(m => m.Questions)

There's builtin way of doing that in MVC. Very simple way, by the way. There are many alternatives, take a look at this article by Phil Haack to inspect them all. One of those is with dictionaries. Quesion.Id will be key, Answer will be value
Sample:
First, create appropriate ViewModels
public class AnswerQuestionViewModel
{
public Quesion Question { get; set; }
public string Answer { get; set; }
}
public class Quesion //
{
public int Id { get; set; }
// Maybe some other properties.
}
Inside ~/Views/Shared/EditorTemplates/, create editor that will render Editor.
#model Models.AnswerQuestionViewModel
#Html.HiddenFor(model => model.Question.Id)
#Html.EditorFor(model => model.Answer)
And ~/Views/ControllerName/ActionName.cshtml
#model IEnumerable<ControllerInspectorTest.Models.AnswerQuestionViewModel>
#using (Html.BeginForm())
{
#Html.EditorForModel();
<p>
<input type="submit" value="Create" />
</p>
}
And when you create post action, parameter will be filled in
[HttpPost]
public ActionResult AnswerQuestions(IEnumerable<AnswerQuestionViewModel> quesions)
{
// questions parameter is filled in correctly
//do save job;
}
Note that question parameter can by type of IList or List too

Related

Partial editor to show single property of model

I have my model as follows
public class PlaceOrder
{
public int orderCode { set; get; }
public string Order_ID { set; get; }
public int orderDetailCode { set; get; }
[Required]
public string Topic { set; get; }
//50 more fields are there
}
Using editorforModel displays all the fields in the model. I want to have a editor helper which takes the property name and only shows editor for that specific property.
I wrote a create/edit/details actions for my model and working fine. What my final goals is that I want to have edit button next to every field on the details view. As soon I click on edit it allows to update and validate the input as well
EDIT
I am using following snippet for edit link
#(Html.Awe().PopupFormActionLink()
.LinkText("Edit")
.Name("editP")
.Url(Url.Action("PropertyEdit", "PlaceOrder", new
{
PropertyName = Html.NameFor(model => model.SubjectCategoryCode),
propertyValue = Html.IdFor(model => model.SubjectCategoryCode),
ordercode = Model.orderCode
})
)
.Title("Editor for " + Html.NameFor(model => model.SubjectCategoryCode))
and I want something that I pass the field name and it dispalys the relevant fields and do the validation
You could just use an EditorFor and a form for each field:
#using Html.BeginForm("action", "controller")
{
#Html.EditorFor(m => m.ordercode)
<input type="submit" />
}
#using Html.BeginForm("action", "controller")
{
#Html.EditorFor(m => m.orderDetailCode)
<input type="submit" />
}
Of course, you would need a different action for each item and you need a way to get the other values as well, since you're only posting one value to the controller. To achieve this you could include a hidden field with the id and retrieve the other values on the server.
There's the Html.EditorFor(m => m.Property) method for this (your model should be set to PlaceOrder to use this helper, as with any statically typed helpers).
Edit: Bah, Kenneth was faster :-).

MVC 3 Razor: Passing data from View using a Model that has classes within it [duplicate]

This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
Complex models and partial views - model binding issue in MVC3
Can you pass data from a View to a Controller when the properties are sitting within a class that is within the Model used in that View?
The problem is that when the Submit happens, it seems that properties of my Model
that belong to a class within that Model do not get populated.
Properties that are not in classes DO get populated.
Just think there is a instantiation problem here but not seeing the path forward.
Here is the Model setup:
namespace AppName.Models
{
public class SuperModel
{
public SuperModel() {
SubModA = new SubModelA();
}
public string myItem1 { get; set; }
public SubModelA SubModA { get; set; }
}
public class SubModelA
{
public string mySubAItem1 { get; set; }
}
}
Here is the View:
#model AppName.Models.SuperModel
#{
ViewBag.Title = "My Page Title";
}
<h2>My Page Title:</h2>
#using (Html.BeginForm("NextController", "NextControllerFolder", new { SuperModel = Model }, FormMethod.Post))
{
#{
Model.myItem1 = DateTime.Now.ToShortDateString();
Model.SubModA.mySubAItem1 = DateTime.Now.ToShortDateString();
}
#Html.HiddenFor(m => m.myItem1)
#Html.HiddenFor(m => m.SubModA.mySubAItem1)
<p>
<button name="submit" value="Submit"><b>Continue</b></button>
</p>
}
Here is the Controller:
[HttpPost]
public ActionResult NextController(string button, SuperModel model, string returnUrl)
{
// PROBLEM IS HERE>>>
///model.myItem1 has a value equal to the current date
// model.SubModA.mySubAItem1 is null
return(model);
}
Hope this question made sense. Hope the answer is just around the corner! Thanks!
Try this:
#Html.HiddenFor(m => m.SubModA.mySubAItem1)
will work.
Replace following line in your code
#Html.HiddenFor(m => m.SubModelA.mySubAItem1)
with this one
#Html.HiddenFor(m => m.SubModA.mySubAItem1)
Hope this help!

ASP.NET MVC, passing Model from View to Controller

I'm having trouble with ASP.NET MVC and passing data from View to Controller. I have a model like this:
public class InputModel {
public List<Process> axProc { get; set; }
public string ToJson() {
return new JavaScriptSerializer().Serialize(this);
}
}
public class Process {
public string name { get; set; }
public string value { get; set; }
}
I create this InputModel in my Controller and pass it to the View:
public ActionResult Input() {
if (Session["InputModel"] == null)
Session["InputModel"] = loadInputModel();
return View(Session["InputModel"]);
}
In my Input.cshtml file I then have some code to generate the input form:
#model PROJ.Models.InputModel
#using(Html.BeginForm()) {
foreach(PROJ.Models.Process p in Model.axProc){
<input type="text" />
#* #Html.TextBoxFor(?? => p.value) *#
}
<input type="submit" value="SEND" />
}
Now when I click on the submit button, I want to work with the data that was put into the textfields.
QUESTION 1: I have seen this #Html.TextBoxFor(), but I don't really get this "stuff => otherstuff". I concluded that the "otherstuff" should be the field where I want to have my data written to, in this case it would probably be "p.value". But what is the "stuff" thing in front of the arrow?
Back in the Controller I then have a function for the POST with some debug:
[HttpPost]
public ActionResult Input(InputModel m) {
DEBUG(m.ToJson());
DEBUG("COUNT: " + m.axProc.Count);
return View(m);
}
Here the Debug only shows something like:
{"axProc":[]}
COUNT: 0
So the returned Model I get is empty.
QUESTION 2: Am I doing something fundamentally wrong with this #using(Html.BeginForm())? Is this not the correct choice here? If so, how do I get my model filled with data back to the controller?
(I cannot use "#model List< Process >" here (because the example above is abbreviated, in the actual code there would be more stuff).)
I hope someone can fill me in with some of the details I'm overlooking.
Change your view to some thing like this to properly bind the list on form submission.
#using(Html.BeginForm()) {
for(int i=0;i<Model.axProc.Count;i++){
<span>
#Html.TextBoxFor(model => model.axProc[i].value)
</span>
}
<input type="submit" value="SEND" />
}
In #Html.TextBoxFor(stuff => otherstuff) stuff is your View's model, otherstuff is your model's public member.
Since in the View you want to render input elements for the model member of a collection type (List), you should first create a separate partial view for rendering a single item of that collection (Process). It would look something like this (name it Process.cshtml, for example, and place into the /Views/Shared folder):
#model List<PROJ.Models.Process>
#Html.TextBoxFor(model => p.value)
Then, your main View would look like this:
#model PROJ.Models.InputModel
#using(Html.BeginForm()) {
foreach(PROJ.Models.Process p in Model.axProc){
#Html.Partial("Process", p)
}
<input type="submit" value="SEND" />
}
Also, check that the loadInputModel() method actually returns something, e.g. not an empty list.

Help with asp.net mvc nested model binding

So I have this demo project almost completely working.
public class Project
{
public int ID { get; set; }
[Required]
public string Name { get; set; }
public virtual ICollection<Task> Tasks { get; set; }
}
public class Task
{
public int ID { get; set; }
[Required]
public string Name { get; set; }
public int ProjectID { get; set; }
public virtual Project Project { get; set; }
}
Controller
public ActionResult Edit(int id)
{
var project = db.Projects.Where(p=>p.ID==id).Single();
return View(project);
}
[HttpPost]
public ActionResult Edit(Project project)
{
if (ModelState.IsValid)
{
var dbProject = db.Projects.Where(p => p.ID == project.ID).Single();
UpdateModel(dbProject);
db.SaveChanges();
TempData["Success"] = "Modelo Valido";
}
return RedirectToAction("Index");
}
View//strongly typed for project
#using (Html.BeginForm())
{
#Html.ValidationSummary(true)
<fieldset>
<legend>Project</legend>
#Html.HiddenFor(model => model.ID)
<div class="editor-label">
#Html.LabelFor(model => model.Name)
</div>
<div class="editor-field">
#Html.EditorFor(model => model.Name)
#Html.ValidationMessageFor(model => model.Name)
</div>
<h1>Tasks</h1>
#Html.EditorFor(m => m.Tasks)
<p>
<input type="submit" value="Save" />
</p>
</fieldset>
}
EditorTemplate
#model MvcApplication2.Models.Task
<span>Task</span>
<br />
#Html.LabelFor(m => m.Name)
#Html.EditorFor(m => m.Name)
#Html.HiddenFor(m => m.ID)
#Html.HiddenFor(m => m.ProjectID)
#Html.ValidationMessageFor(m => m.Name)
The view displays this
The problem is that when I submit the form the Tasks are populated with everything except the virtual Project property... so the error i get it is
The operation failed: The relationship could not be changed because
one or more of the foreign-key properties is non-nullable. When a
change is made to a relationship, the related foreign-key property is
set to a null value. If the foreign-key does not support null values,
a new relationship must be defined, the foreign-key property must be
assigned another non-null value, or the unrelated object must be
deleted.
Here is a pic of my debugging breakpoint result
Please Help.
UPDATE:
I have changed my controller action to this
[HttpPost]
public ActionResult Edit(Project project)
{
if (ModelState.IsValid)
{
db.Entry(project).State = EntityState.Modified;
db.SaveChanges();
TempData["Success"] = "Modelo Valido";
return RedirectToAction("Index");
}
return View(project);
}
it is still not working correctly.
Now changes made to the Name of the project are updated correctly in the database. but changes made to any Task Name are ignored completely.
i believe #Html.EditorFor(m => m.Tasks) is generating html like (approximately)
<label>Name</label>
<input type="text" name="Tasks[0].Name" id="auto-gen-id"/>
<input type="hidden" name="Tasks[0].ID" id = "auto-gen-id"/>
<input type="hidden" name="Tasks[0].ProjectID" id = "auto-gen-id"/>
<!--html for validation span-->
Above is the approximate html generated for first Task in Collection and similar html will be generated for each task in the collection. The only difference is that index will be incremented in name attributes of all inputs i.e Tasks[1].Name, Tasks[1].ProjectID etc. This portion will actually bind to the Collection<Task> Tasks property of Project but you can see that in detail portion you don't have any inputs like
<input type="whatever" name="Tasks[0].Project.ProjectID" .../>
<input type="whatever" name="Tasks[0].Project.Name" ..../>
Modelbinder needs input elements with proper naming conventions to bind values to all properties of action method parameters. For testing purpose you can inlude these two lines in your Editor template for Task
#Html.TextBoxFor(x=>x.Project.ID)
#Html.TextBoxFor(x=>x.Project.Name)
input proper values for them in the form and you will have Project property of Task populated with these values. But may not be what you desire i.e entering project information twice and this may not be needed (if u are using Linq to sql its sure not needed). When you call your ORM for attaching entities to db entities it will know which Project elements, current Task belongs to.
Side Note: When you have problems with modelbinding, always pay attention to generated html. Generated html will dictate which form values will map to which properties of the model as long as you are using default modelbinder. it becomes especially important if you are having master detail kind of scenario as in your example.
I have found a way to get this to work but Im not completely happy with the approach.
see this question on how to refactor my current code to see how I am currently (hopefully temporarily doing it)
Help improving (refactoring) my code. Automapper - EF - asp.net mvc-3

How to pass data to the view in mvc asp.net?

let me ask the question first.
Where is the correct place to call a function that load a list of values to be display on a view?
I create a controller like this
public ActionResult Create()
{
SeaModel newSea = new SeaModel();
return View("Season/CreateSea", newSea);
}
//I not quite sure if this should go here or in another place
partial class seaDataContext
{
public List<string> getSeaSettings()
{
var seaSettings = from p in settings
where p.setting == "periods"
select p.value;
return seaSettings.ToList<string>();
}
}
The model is like
public class SeaModel
{
[Required(ErrorMessage="*")]
[Display(Name = "Period Name")]
public string periods { get; set; }
}
Which create a view like
#using (Html.BeginForm()) {
#Html.ValidationSummary(true, "Please correct the following errors.")
<fieldset>
<legend>Fields</legend>
<div class="editor-label">
#Html.LabelFor(model => model.periods)
</div>
<div class="editor-field">
#Html.Select(model => model.periods, ****My doubt comes here****)
#Html.ValidationMessageFor(model => model.periods)
</div>
<p>
<input type="submit" value="Create" />
</p>
</fieldset>
}
so, How and where do I pass the return of getSeaSettings() to the view?
Thanks
best practice is to make a Selectlist in your Model for this dropdown.
however you also can use the more easy option: using ViewData
public ActionResult Create()
{
SeaModel newSea = new SeaModel();
ViewData["myDropDown"] = new SelectList(listOfObjects, "valueOfTheObjectLikeID", "NameYouWantToShowInDropdown");
return View("Season/CreateSea", newSea);
}
then:
#Html.Select(model => model.periods, ViewData["myDropDown"] as SelectList)
dont forget in your [HttpPost] method to also fill in the viewdata if you'r validation fails, so the dropdown can be rebuilt.
You need to look at repository pattern. Have a look at this tutorial at asp.net site
http://www.asp.net/mvc/tutorials/creating-model-classes-with-linq-to-sql-cs
Stefanvds's approach was what I used to do.
But I found out there is a better way using additionalViewData.
Use this EditorFor HTML Helper extension method.
http://msdn.microsoft.com/en-us/library/ff406462.aspx
Instead of passing Select List Items into ViewData in the Controller, you do this in your View.
Pass in your list items as an anonymous object for the additionalViewData parameter.
Important thing is to use the same name as your Property Name.
#Html.EditorFor(
m => m.MyPropertyName,
new { MyPropertyName = Model.ListItemsForMyPropertyName }
);
Of course, you are passing in a View Model object.
public class MyViewModel
{
public int MyPropertyName;
public IList<SelectListItem> ListItemsForMyPropertyName;
}
EditorFor method uses your existing Editor View Templates.
So you don't need to specify CSS class names and HTML attributes again like when you use the Html.DropDown( ) method.
For example,
//------------------------------
// additionalViewData
//------------------------------
#Html.EditorFor(
m => m.MyPropertyName,
new { MyPropertyName = Model.ListItemsForMyPropertyName }
)
//------------------------------
// traditional approach requires to pass your own HTML attributes
//------------------------------
#Html.DropDown(
"MyPropertyName",
Model.ListItemsForMyPropertyName,
new Dictionary<string, object> {
{ "class", "myDropDownCssClass" }
}
);
//------------------------------
// DropDownListFor still requires you to pass in your own HTML attributes
//------------------------------
#Html.DropDownListFor(
m => m.MyPropertyName,
Model.ListItemsForMyPropertyName,
new Dictionary<string, object> {
{ "class", "myDropDownCssClass" }
}
);
That is why I like the additionalViewData approach more.
Because, the HTML code rendered relies on the Editor Templates completely.
Also, using specialized View Models make your code cleaner and easier to maintain.
Hope it helps.

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