I have a viewModel that contains an object. I've defined a custom editor template for that object, which allows me to edit each of the children of that object. The children values aren't required serverside (so I don't have any Required annotations), however if the user reaches this particular input, it should be required.
Is there any way I can inspect the values of these children objects (within the viewModel) in the POST method, and return some errors to the view if they are null?
I'm using Razor.
On the server-side, you could check the child objects of the class in your action,
[HttpPost]
public ActionResult Edit(MyClass myClass)
{
if (myClass.Children.Any(child => child == null))
{
foreach(var child in myClass.Children
.Where(child => child == null)
.Select((item, index) => new { Item = item, Index = index))
{
ModelState.AddModelError(
string.Format("Children[{0}]", child.Index),
"Must be required");
}
return this.View("...");
}
}
What you can do is to write a function that will be check user input (on change in that field)
if the user reaches this particular input
and if user reaches that particular input you use jQuery to add #class = "required" HTML attribute to your object. From that moment on it will become required
Take a look here: this is jQuery validator for required field based on some condition. I think this is exactly what you're after
Edit
Your other option is to use AJAX to go back to server to verify what you're looking for. Example is here
Hope this makes sense and is of help to you.
Related
I have a model with various properties but the one of interest is a List of another type of Model.
For example:
public class User
{
public string Name { get; set; }
public string Description { get; set; }
public IEnumerable<UserInterest> Interests { get; set; }
}
I then use an Editor Template within my view to render out a view for each item of the model items.
#Html.EditorFor(x => x.Interests)
The EditorFor template looks something like:
#model Interest
<div>
#Html.HiddenFor(x => x.Id)
#Html.TextBoxFor(x => x.InterestText)
#Html.CheckBoxFor(x => x.Delete)
....
</div>
Something very similar to the accepted answer here: Model Containing List of Models (MVC-3, Razor)
My question is - how would you from the client-side (jQuery) create a new item within the property without going back to the server. I currently have a rough way of doing it whereby I post the data back to my controller which returns the model back with a new blank item within the Interests property.
This seems to be overkill making a HTTP request and not very elegent. I was thinking of using jQuery .Clone() but not entirely sure on what I'd need to do in terms of naming the elements and clearing existing values.
So does anybody have any suggestions. I'm hoping to get more opinions and different approaches.
You can simply create the Textbox and checkbox on the fly and add that to the DOM. When saving it, Use jQuery ajax to post that data ( new record data) to an action method and save it there. Return a status back (Succcess /Falied) from your action method to your client side code ( your callback function of jQuery ajax/post) and check it there. If it is success, Show a success message to the user and append the new item to the existing list.
Sample jSFiddle : http://jsfiddle.net/carwB/2/
If you want to return some complex data ( ex : All new records with its id etc..) along with the status, you may return JSON from your action method.
EDIT : To keep your Model binding works with the newly added dynamic elements, you need to follow the naming convention of the elements.
The trick is to keep the id property value of the html element in this format.
CollectionName_ItemIndex__PropertyName
and name property value in this format
CollectionName[ItemIndex].PropertyName
I created a sample working program and explained it how it works Here based on your requirements.
In such situations I prefer to use client templating. You send data to server with ajax and then receive JsonResult. Look at JsRender this is javascript lib without jQuery dependency.
1.Create two partial view one is for list item and second one is creation
2.First partail view should be inside the div which has id 'divMdeolList'
3.and Creation view will have the code like that
#using (Ajax.BeginForm("SubmitData", new AjaxOptions { UpdateTargetId = "divMdeolList" }))
{
#Html.TextBoxFor(x => x.InterestText)
<p>
<input type="submit" value="Create" />
</p>
}
4. And then create a ActionResult type action on controller that will render the partialview
public ActionResult SubmitData(YourModel model)
{
//Do : save the record
return PartialView("FirstPartailView", model);
}
This will update the View without postback
I'm using MVC3 (razor) and i'm trying to get the following working.
I have a list of snippets. These snippets have some general settings and then have a translation for an unknown ammount of languages.
Now i'm trying to do the following:
On the 'Create' page (url: Screen) of a snippet i set the general settings. under that there is a list of filled translations (empty at the start). When you press the 'Opslaan' button, i want the form to save the general settings and the list of translations.
When i push the 'Add' button i want to submit the complete viewmodel (settings + list of translations) to an other page where i can fill in a translation. After i filled in a translations, i want to return to this page (url: Screen). Here, a translation is filled in the list.
Now i'm doing someting wrong, because i cant get the viewmodel to submit to the 2nd page.
this is my code:
button 'add translation':
#Html.ActionLink("Add", "CreateTranslation", new { oSnippeteditviewmodel = this.Model }, null)
SnippetController:
public ActionResult Create()
{
SnippetEditViewModel oItem = new SnippetEditViewModel();
oItem.lSnippetsPerLanguage = new List<SnippetPerLanguageEditViewModel>();
return View(oItem);
}
[HttpPost]
public ActionResult Create(SnippetEditViewModel Snippeteditviewmodel)
{
if (ModelState.IsValid)
{
Snippeteditviewmodel.Bookmark = Snippeteditviewmodel.Bookmark.Replace(' ', '_');
_repoSnippet.CreateSnippet(Snippeteditviewmodel);
return RedirectToAction("Index");
}
return View(Snippeteditviewmodel);
}
public ActionResult CreateTranslation(SnippetEditViewModel oSnippeteditviewmodel)
{
return View(oSnippeteditviewmodel);
}
And in the controller, action CreateTranslation the object 'oSnippeteditviewmodel' stays null.
annyone who has a simular problem? Or a solution?
First, you should try to generate action link like this
#Html.ActionLink("Add", "CreateTranslation", this.Model, null)
In this case mvc will try to pass correctly serialized model values for your link and if your model is simple enough, CreateTranslations will get its model correctly. But, I would not do it that way. Generated link is static. What if user changes Snippet values on client side? When it comes to adding Translation, all the changed form values will be lost (Link will pass initial, server generated values). So, you should try one of the followings
Create the form with two buttons, one for CratingTranslation and one for Saving. When creating translation, dynamically change form's action and method parameters to GET the CreateTranslation action. This way, form will serialize all its current Snippet settings and pass to desired action, and you get the current snippet model passed to CreateTranslation action.
Use ajax. Just dynamically inject translation creation input fields into same page. That's simple and more user friendly (no bundle of navigations), and more http traffic is reserved (Passing all the translations and snippet to second page, and then returning all of these + 1 translation could get you in trouble). I would reccomend this approach. This is far more simple than first or your approaches.
I am not getting you properly but if you wanna add data by "create" controller then you don't need to specify object in "oSnippeteditviewmodel". You can get all form data by
Request.Form["controlName"]
and fill the Snippeteditviewmodel data member by above and save that.
I have a bunch of text inputs on my page (HTML.TEXTBOX, generated through for loop), and I want to read their values and commit to database only when user has modified something in those textboxes.
What would be a proper way to do that? (Do you think it may make more sense to commit the entire thing to database if number of textboxes is less than 100?)
Also, in general, how would I read values from a bunch on textboxes and commit to the database? I would need something that uses a key-value pair, where key would be the id and value would be that input in the textbox.
Unless you use for example JavaScript and hidden fields to keep track of user changes, there is no way for you to know which fields have been modified without querying the database, since the web in general, and ASP.NET MVC in particular, is stateless. However, if you loop out the fields with their values filled in with data stored in an object, you can probably save that object in a session variable to compare against on the next request.
Pseudo-example:
public ActionResult GetFormView()
{
var values = (select relevant information from db and store in a
IQueryable<Dictionary<string, string>> or something similar
where you have a relation between input field id/name and value);
Session["TheInputListValues"] = values;
return View(values); // Your view renders your list of input fields
}
[AcceptVerbs(HttpVerbs.Post)]
public ActionResult SaveChanges(FormCollection form)
{
var oldValues = (Dictionary<string, string>)Session["TheInputListValues"];
var changedValues = new Dictionary<string, string>();
foreach(string key in form.AllKeys)
{
if(oldValues.ContainsKey(key))
{
if (oldValues[key] != form[key])
{
changedValues(key, form[key]);
}
}
}
SaveToDB(changedValues);
return Redirect("SomeWhereElse"); // PRG is king!
}
I haven't tested this implementation, but it's worth a try =)
I have done something similar using jQuery and it works pretty well. Attach a behavior to the textboxes where if the data changes then submit it's value to an action that saves the data.
$(function(){
$("input[type='text']").change(function(){
$.post("/SaveChanges",{id: $(this).attr("id"),value : $(this).attr("text")});
});
});
This would be assuming you had ID's that were some sort of unique key to you record on each input.
<input id="4576" name="4576"/>
you could also have a callback that would say add a class to this field letting them know that the information was saved by changing it to green or something.
Check this out for more details:
http://docs.jquery.com/Ajax/jQuery.post
Is it possible to disable a certain action parameter from retaining its value across requests?
[HttpPost]
public ActionResult MyAction(string value1, string value2)
{
if(value1=="hi")
ModelState.AddModelError("value1", "Can't have hi");
//do stuff
if(ModelState.IsValid)
return RedirectToAction("Finish");
else
return View()
}
[HttpGet]
public ActionResult MyAction()
{
return View()
}
The view consists of a simple form with two input boxes (value1 and value2). Once submitted and validation fails, the view is returned. I want to always have the value of the textbox in the view to be empty.
The value for the textbox "value1" is retained if the the model is invalidated.
I tried to declare the textbox as <%= Html.TextBox("value1", null) %> but the value is still retained. I also tried to use [Bind(Exclude="value1")] but that dosen't work on a single variable.
Update 2:
I'm doing this for a textbox that is used for Captcha (custom solution) input. I want the textbox to be cleared any time the page is loaded, but I want validation to remain.
Try calling
ModelState["value1"].Value
= new ValueProviderResult(null, string.Empty, CultureInfo.InvariantCulture);
before you return the view from within your controller action.
What this does is keep all the errors associated with the key "value1", but replaces the value with an empty value.
What are you doing that's causing it to be retained? There isn't anything like ViewState in MVC that will persist a value over multiple requests unless you're writing code or using form fields to make it do so.
What does the view look like? Is this action method being called via GET or POST? What's the "do stuff" contained in your method?
Edit: You're still showing //do stuff in your example code. Does that stuff contain any references to ViewData? Your question is about binding, but I don't see any binding happening. Maybe this is beyond my understanding.
Edit 2: Glad Phil saw this one! The original question didn't mention the ModelState.
I have a controller with two actions:
[AcceptVerbs("GET")]
public ActionResult Add()
{
PrepareViewDataForAddAction();
return View();
}
[AcceptVerbs("POST")]
public ActionResult Add([GigBinderAttribute]Gig gig, FormCollection formCollection)
{
if (ViewData.ModelState.IsValid)
{
GigManager.Save(gig);
return RedirectToAction("Index", gig.ID);
}
PrepareViewDataForAddAction();
return View(gig);
}
As you can see, when the form posts its data, the Add action uses a GigBinder (An implemenation of IModelBinder)
In this binder I have:
if (int.TryParse(bindingContext.HttpContext.Request.Form["StartDate.Hour"], out hour))
{
gig.StartDate.Hour = hour;
}
else
{
bindingContext.ModelState.AddModelError("Doors", "You need to tell us when the doors open");
}
The form contains a text box with id "StartDate.Hour".
As you can see above, the GigBinder tests to see that the user has typed in an integer into the textbox with id "StartDate.Hour". If not, a model error is added to the modelstate using AddModelError.
Since the gigs property gigs.StartDate.Hour is strongly typed, I cannot set its value to, for example, "TEST" if the user has typed this into the forms textbox.
Hence, I cant set the value of gigs.StartDate.Hour since the user has entered a string rather than an integer.
Since the Add Action returns the view and passes the model (return View(gig);) if the modelstate is invalid, when the form is re-displayed with validation mssages, the value "TEST" is not displayed in the textbox. Instead, it will be the default value of gig.StartDate.Hour.
How do I get round this problem? I really stuck!
I think the problem is that your ViewModel does not match closely enough with your View. It's really important in MVC that your ViewModel matches your View as closely as possible.
In your ViewModel you're assuming an integer, but in your View you're using a TextBox to render the property, which will allow any kind of text. There's a mismatch here and the difficulties you are experiencing trying to map them is a symptom of the mismatch.
I think you should either:
1. Change the type of the ViewModel property to string and then do validation in your controller to ensure the string entered is actually a number or:
2. Change the control that the View renders to a control that will only allow a number to be entered via a custom control or Javascript validation (as #Qun Wang recommends)
Personally, I'd recommend option 1. That way the ViewModel is not dependent on the View implementation.
Could you do this in your PrepareViewDataForAddAction method?..
if (!ViewData.ModelState.IsValid)
{
ViewData["StartDate.Hour"] = "Error";
}
The other fields on the form will still populate based on the properties of the Gig object.
I think you need to do some basic client side validation first.
don't allow it to post to the server.