This is part of a an MVC model class:
[Required]
[StringLength(2, ErrorMessage = "Two characters.")]
public string StateProvince { get; set; }
If I submit my form with a blank StateProvince, I will get an error message. If I submit it with one character in StateProvince, no problem. Here's how I get back error messages:
if (!ModelState.IsValid)
{
MyMessage ErrMsg = new MyMessage();
ErrMsg.StatusCode = 101;
ErrMsg.StatusMsg = string.Join("; ", ModelState.Values.SelectMany(x => x.Errors).Select(x => x.ErrorMessage));
return "[" + JsonConvert.SerializeObject(ErrMsg) + "]";
}
MyMessage is structured like so:
public class MyMessage
{
public int StatusCode { get; set; }
public string StatusMsg { get; set; }
}
Am I right to conclude that the StringLength decoration only serves to create client-side validation in the html input field?
Since I'm coding the HTML myself and not using Asp.Net to generate it, then should I just omit the StringLength decoration on the model field and instead write server-side validation code for that in the controller? (And that violates MVC, right?)
Oops! Sorry! StringLength was working. It only prevents excess characters, not minimum number of characters. I know there's code for enforcing an exact length; I've seen it before and will look it up.
Related
I have a ViewModel with a String property and the following Data Annotation :
Edit to work with string
[DataType(DataType.Date, ErrorMessage="Not Working !!!")]
public String StringBirthDate1 { get; set; }
That's my view
#Html.EditorFor(model => model.StringBirthDate1 )
#Html.ValidationMessageFor(model => model.StringBirthDate1)
If I run my application and put an invalid Date like '---' or 29.02.1900 I don't get any validation error !
Ok I've given up trying to use built-in MVC tools for data validation !
I did a custom Validation Attribute :
public class ValidDateStringAttribute : ValidationAttribute
{
public override bool IsValid(object value)
{
DateTime dtout;
if (DateTime.TryParse(value.ToString(), out dtout ))
{
return true;
}
return false;
}
}
Here is my View Model decorated with the custom attribute :
[ValidDateString(ErrorMessage="Invalid date format")]
public String BirthDate1 { get; set; }
Works like a charm :-)
It seems to me, that [DataType(DataType.Date, ErrorMessage="Not Working !!!")] working when it attached to string property. Try to use:
[DataType(DataType.Date, ErrorMessage="Not Working !!!")]
puplic string StringBirthDate1{get;set;}
public DateTime BirthDate1
{
get{return DateTime.Parse(StringBirthDate1);}
set{StringBirthDate1 = value.ToString();}
}
I didn't like any of the solutions I found so I kept poking at possibilities until I came up with one I do like. I added a regular expression validator utilizing the regular expression from this article: http://answers.oreilly.com/topic/226-how-to-validate-traditional-date-formats-with-regular-expressions/
[Required(ErrorMessage = "Birthdate is required. [MM/DD/YYYY]")]
[RegularExpression(#"^([1-9]|0[1-9]|1[0-2])[- / .]([1-9]|0[1-9]|1[0-9]|2[0-9]|3[0-1])[- / .](1[9][0-9][0-9]|2[0][0-9][0-9])$", ErrorMessage = "Birthdate must be in MM/DD/YYYY format.")]
public Nullable<DateTime> Birthdate { get; set; }
The result is, if the field is blank I get the required error message and if anything is in the field, but it is not a valid date, I get the regular expression message.
I might add that it seems very silly that [DataType] doesn't accept an error message. I tried exactly like the original author of this thread. That would have been logical and intuitive.
I am following Scott Gu's blog: here
In his Blog he talks about client and server side validation.
How does one validate if username has already been taken and display this as a validation error message to the user?
In Scott's blog, this would be the same as validating if Title is unique:
public class Dinner
{
public int DinnerID { get; set; }
[Required(ErrorMessage = "Please enter a Dinner Title")]
[StringLength(20, ErrorMessage = "Title is too long")]
public string Title { get; set; }
[Required(ErrorMessage = "Please enter the Date of the Dinner")]
public DateTime EventDate { get; set; }
[Required(ErrorMessage = "Please enter the location of the Dinner")]
[StringLength(30, ErrorMessage = "Address is too long")]
public string Address { get; set; }
[Required(ErrorMessage = "Please enter your email address")]
[RegularExpression(".+\\#.+\\..+", ErrorMessage = "Please enter a valid email address")]
public string HostedBy { get; set; }
public virtual ICollection<RSVP> RSVPs { get; set; }
}
My first guess is that somehow this is done within the Model Controller, here:
//
// POST: /Home/Create
[HttpPost]
public ActionResult Create(Dinner dinner)
{
if (ModelState.IsValid)
{
nerdDinners.Dinners.Add(dinner);
nerdDinners.SaveChanges();
return RedirectToAction("Index");
}
return View(dinner);
}
And because the Title is stored in a database server, this would be server side validation.
I know how to check if the Title is unique, but I do not know how to make the validation message appear in the View like it does using declaratives like [Required] or [StringLength()]. For example, here is how I can check for uniqueness:
[HttpPost]
public ActionResult Create(Dinner dinner)
{
if (ModelState.IsValid)
{
foreach (var existingDinner in nerdDinners.Dinners)
{
if(existingDinner.Title == dinner.Title)
{
**// TODO: display validation error message?**
}
}
nerdDinners.Dinners.Add(dinner);
nerdDinners.SaveChanges();
return RedirectToAction("Index");
}
return View(dinner);
}
Using my imagination, and a magic wand, I would want to create a new declarative called [TitleIsUnique] that performs like the other validation declaratives.
Thank you in advance for your assistance.
You could create a custom attribute as mentioned and use IValidateObject but I prefer to add my errors to the ModelState in one of the layers in my application.
For this you can use ModelState.AddModelError
If you use ModelState.AddModelError("Title", "Title must be unique"); it will add an error to the Title field.
If you use ModelState.AddModelError("*", "Title must be unique"); it will add a general error message for the page.
[HttpPost]
public ActionResult Create(Dinner dinner)
{
if (ModelState.IsValid)
{
if(nerdDinners.Dinners.Any(d => d.Title == dinner.Title))
{
ModelState.AddModelError("Title", "The title is not unique");
return View(dinner);
}
nerdDinners.Dinners.Add(dinner);
nerdDinners.SaveChanges();
return RedirectToAction("Index");
}
return View(dinner);
}
You are probably looking at implementing your own attribute derived from CustomAttribute. Take a look at this blog post http://blogs.msdn.com/b/adonet/archive/2011/05/27/ef-4-1-validation.aspx - it shows how to validate uniqueness. In the post IValidatableObject interface is used to perform validation but you should be able to the same by creating CustomAttribute.
I have an input form containing several input fields. Each input field has a ElementModel which has properties basically for the label and the value. The input fields to display are specified in a XML document, so I have kind of a dynamic view with only a list of elements.
The problem is, that each element should be either displayed as a decimal or as percentage value. And of course, if it's a percentage value, the user shoud be able to input something like "45%" and the value in the model should then be 0.45.
My first thought when I found this article was to use an abstract view model class with an abstract property for the value and to define a PercentageElementModel deriving from my base ElementModelclass that makes use of a custom model binder. Unfortunately, if I use that abstract base class in my view, the data annotations made in the PercentageElementModelare ignored.
Do you have any idea of how I can solve this? I don't want to use strings in my view model and do the parsing by myself as this will break the MVC pattern. Are there some other ways to achieve my goal?
Here are some code snippets:
public abstract class ElementModel
{
public string ElementName { get; set; }
public ElementType ElementType { get; set; }
public abstract double? ElementValue { get; set; }
}
public class PercentageElementModel : ElementModel
{
[DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:P2}")]
public override double? ElementValue { get; set; }
}
I came up with another solution as my problem is more a matter of display formatting than of validation: I wrote a custom ModelBinder which checks the input string of the text box. If it ends with a trailing '%' sign, I will devide the value by 100. Here's the code.
public class DoubleModelBinder : IModelBinder
{
public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
{
var valueResult = bindingContext.ValueProvider.GetValue(bindingContext.ModelName);
var modelState = new ModelState { Value = valueResult };
double? actualValue = null;
try
{
// cut trailing '%'
if (valueResult.AttemptedValue.EndsWith("%"))
{
var strValue = valueResult.AttemptedValue.Substring(0, valueResult.AttemptedValue.Length - 1);
actualValue = double.Parse(strValue, valueResult.Culture) / 100;
}
else
{
actualValue = Convert.ToDouble(valueResult.AttemptedValue, CultureInfo.CurrentCulture);
}
}
catch (FormatException e)
{
modelState.Errors.Add(e);
}
bindingContext.ModelState.Add(bindingContext.ModelName, modelState);
return actualValue;
}
}
The rest happens in the view itself. To display the correct format, I use a simple ToString() method with a percentage format string assigned if needed. And if the user enters a numeric value without '%', a jQuery's blur() event will append the '%' sign to the user's input. Perfectly works for me although this is not the best answer for my own question.
I'm having trouble with my ASP.NET MVC 3 application. I have 2 propertiesin my model whereby I only want 1 of them required in my view based on whichever one is empty. So for example, if I enter a phone number then email is no longer required and vice versa, but if I leave both empty, then either 1 should be required, below is my model:
[Display(Name = "Contact Phone Number:")]
[MaxLength(150)]
public string ContactPhoneNumber { get; set; }
[Display(Name = "Contact Email Address:")]
[MaxLength(100)]
public string ContactEmailAddress { get; set; }
Would I need to create a custom attribute to validate my model and if so, how would I achieve this?
You can implement IValidatableObject on your class and provide a Validate() method that implements your custom logic. Combine this with custom validation logic on the client if you prefer to ensure that one is supplied. I find this easier than implementing an attribute.
public class ContactModel : IValidatableObject
{
...
public IEnumerable<ValidationResult> Validate( ValidationContext context )
{
if (string.IsNullOrWhitespace( ContactPhoneNumber )
&& string.IsNullOrWhitespace( ContactEmailAddress ))
{
yield return new ValidationResult( "Contact Phone Number or Email Address must be supplied.", new [] { "ContactPhoneNumber", "ContactEmailAddress" } );
}
}
}
To get everything working at client side you'll need to add the following script to your view:
<script type="text/javascript">
$(function() {
$('form').validate();
$('form').rules('add', {
"ContactPhoneNumber": {
depends: function(el) { return !$('#ContactEmailAddress').val(); }
}
});
});
</script>
Annotation-based conditional validation can be defined using ExpressiveAnnotations:
[RequiredIf("ContactPhoneNumber == null",
ErrorMessage = "At least email or phone should be provided.")]
public string ContactEmailAddress { get; set; }
[RequiredIf("ContactEmailAddress == null",
ErrorMessage = "At least email or phone should be provided.")]
public string ContactPhoneNumber { get; set; }
Here is a MSDN blog entry about conditional validations: http://blogs.msdn.com/b/simonince/archive/2011/02/04/conditional-validation-in-asp-net-mvc-3.aspx
I know you already have a solution, but I had a similar situation, so maybe my solution will prove helpful to someone else. I implemented a custom attribute with client-side validation. Here is my blog post: http://hobbscene.com/2011/10/22/conditional-validation/
I am using strongly typed views in an MVC3 web app. I've noticed that when a form is submitted, the ViewModel that is passed to the controller only has values for properties that have form elements associated with them. For instance, the example below shows a simple confirmation View with a checkbox and a phone number that the user must confirm before proceeding. When the form is submitted to the controller action, the UserConfirmed property contains a value, but the PhoneNumber property is null.
Is there any way for the ViewModel to retain all of its values or do I have to repopulate the ViewModel properties that do not have form elements associated with them?
The View
#model WebMeterReplacement.ViewModels.Appointment.ScheduleConfirmationViewModel
#using (Html.BeginForm()) {
#Html.ValidationSummary(false)
#Html.CheckBoxFor(model => model.UserConfirmed)
<span>Please confirm before proceeding</span>
<div>
Phone Number: #Model.PhoneNumber
</div>
<input type="submit" value="Confirm"/>
The Controller
[HttpPost]
public ActionResult ScheduleConfirmation(ScheduleConfirmationViewModel model)
{
if (model.UserConfirmed)
{
// add ViewModel data to repository
}
else
{
ModelState.AddModelError("ERROR", WebResources.strERROR_ConfirmSchedule);
}
return View(model);
}
Since your writing the phonenumber as output to the page it won't be automatically posted back (you've found out that part) What you can do is populate an hidden or read-only field with the phonenumber so that it will be posted back to your controller. An second option is to make a new call to your datasource and repopulate your object before saving it back to your datasource.
I generally POST back information like this in a hidden input. I personally use this heavily to pass data needed to return the user exactly where they where before pressing edit.
In your case it's as simple as
#model WebMeterReplacement.ViewModels.Appointment.ScheduleConfirmationViewModel
#using (Html.BeginForm()) {
#Html.ValidationSummary(false)
#Html.CheckBoxFor(model => model.UserConfirmed)
<span>Please confirm before proceeding</span>
<div>
#Html.HiddenFor(m => m.PhoneNumber)
Phone Number: #Model.PhoneNumber
</div>
<input type="submit" value="Confirm"/>
For future reference:
If your passing complex objects back you need one hidden field per attribute (Hiddenfor does NOT iterate)
View
WRONG
#Html.HiddenFor(m => m.PagingData)
RIGHT
#Html.HiddenFor(m => m.PagingData.Count)
#Html.HiddenFor(m => m.PagingData.Skip)
#Html.HiddenFor(m => m.PagingData.PageSize)
Action
public HomeController(AViewModel Model)
{
PagingData PagingData = Model.PagingData;
Skip = PagingData.Skip;
}
If your passing Arrays you can do it like this
View
#if (Model.HiddenFields != null)
{
foreach (string HiddenField in Model.HiddenFields)
{
#Html.Hidden("HiddenFields", HiddenField)
}
}
Action
public HomeController(AViewModel Model)
{
String[] HiddenFields = Model.HiddenFields;
}
Well, the form will only POST elements that you have created. As you found out, simply writing the phone number out to the page will not suffice. The model binder can only bind those properties which exist in the posted data.
Generally you have a couple of options here:
1) You can create Input elements for all of the properties in your model, using visible elements (like a textbox) for those properties you want to edit, and hidden elements which should be posted back but have no UI
2) Post back a partial representation of your model (as you are doing now), read the entity back in from it's data source (I assume you're using some kind of data source, EF maybe) and then alter the properties of that entity with the ones from your form.
Both scenarios are common but it really depends on the complexity of your model.
I know this thread is a bit old, but thought I'd resurrect it to get feed back on my solution to this.
I'm in a similar situation where my objects are passed to a view, and the view may only display part of that object for editing. Obviously, when the controller receives the model back from the default model binder, and values not posted back become null.. and saving this means that a DB value becomes null just because it wasn't displayed/returned from a view.
I didn't like the idea of creating a model for each view. I know it's probably the right way... but I was looking for a reusable pattern that can be implemented fairly quickly.
See the "MergeWith" method... as this would be used to take a copy of the object from the database and merge it with the one returned from the view (posted back)
namespace SIP.Models
{
[Table("agents")]
public class Agent
{
[Key]
public int id { get; set; }
[Searchable]
[DisplayName("Name")]
[Column("name")]
[Required]
[StringLength(50, MinimumLength = 4)]
public string AgentName { get; set; }
[Searchable]
[DisplayName("Address")]
[Column("address")]
[DataType(DataType.MultilineText)]
public string Address { get; set; }
[DisplayName("Region")]
[Searchable]
[Column("region")]
[StringLength(50, MinimumLength = 3)]
public string Region { get; set; }
[DisplayName("Phone")]
[Column("phone")]
[StringLength(50, MinimumLength = 4)]
public string Phone { get; set; }
[DisplayName("Fax")]
[Column("fax")]
[StringLength(50, MinimumLength = 4)]
public string Fax { get; set; }
[DisplayName("Email")]
[RegularExpression(#"(\S)+", ErrorMessage = "White space is not allowed")]
[Column("email")]
[StringLength(50, MinimumLength = 4)]
public string Email { get; set; }
[DisplayName("Notes")]
[Column("notes")]
[DataType(DataType.MultilineText)]
public string Notes{ get; set; }
[DisplayName("Active")]
[Column("active")]
public bool Active { get; set; }
public override string ToString()
{
return AgentName;
}
public bool MergeWith(Agent a, string[] fields)
{
try
{
foreach (PropertyInfo pi in this.GetType().GetProperties())
{
foreach (string f in fields)
{
if (pi.Name == f && pi.Name.ToLower() != "id")
{
var newVal = a.GetType().GetProperty(f).GetValue(a,null);
pi.SetValue(this, newVal, null);
}
}
}
}
catch (Exception ex)
{
return false;
//todo: Log output to file...
}
return true;
}
}
}
And to use this in the controller.. you'd have something like..
[HttpPost]
public ActionResult Edit(Agent agent)
{
if (ModelState.IsValid)
{
Agent ag = db.Agents.Where(a => a.id == agent.id).ToList<Agent>().First<Agent>();
ag.MergeWith(agent, Request.Params.AllKeys);
db.Entry(ag).State = EntityState.Modified;
db.SaveChanges();
return RedirectToAction("Index");
}
return View(agent);
}
This way, during post back, it takes the object from the database, and updates it with object from view... but only updates the values that were posted back.. So if you have a field like "address" or something that doesn't appear in the view.. it doesn't get touched during the update.
I've tested this so far and i works for my purposes, tho i welcome any feedback as I'm keen to see how others have overcome this situation. It's a first version and i'm sure it can be implemented better like through an extension method or something.. but for now the MergeWith can be copy/pasted to each model object.
Yes, Just place hidden fields in the form for those values which you are not using and want to return to server control.
Thanks