please help me with asp.net MVC 2 application.
I have class:
public class Account
{
[Required(....)]
[RegularExpression("....")]
public string AccountCode{ get; set; }
public string BankName{ get; set; }
}
And another one:
public class BankPageModel
{
public bool AccountRequired {get; set; }
public Account NewAccount {get;set;}
}
Imagine I have page and form on it with 2 text boxes (AccountCode and BankName) and check box (AccountRequired). So when I post the form, if check box is checked, I want to validate AccountCode to be required and to fit regular expression. But if it is not checked, I just want to ignore those text boxes and to post the form. But Required and RegularExpression attributes cannot be used then, they are preventing it. I could make class attribute, but what if I have more textboxes with similar validation, I don't want to make class attribute for each of them...
What do you think? Thanks in advance.
The best way to do this on the server side, is to have your model implement IValidatableObject and then do the following:
public class BankPageModel : System.ComponentModel.DataAnnotations.IValidatableObject
{
public bool AccountRequired { get; set; }
public Account NewAccount { get; set; }
public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
{
// only perform validation here if account required is checked
if (this.AccountRequired)
{
// check your regex here for account
if (!RegEx.IsMatch(this.NewAccount.AccountCode, "EXPRESSION"))
{
yield return new ValidationResult("Error");
}
}
}
}
Doing things this way helps keep your controllers lean and encapsulates all validation logic in your model. This method could also be verified client side with unobtrusive javascript.
You don't need to use DataAnnotations to perform validation, they just make things easier for common validation scenarios (and you can get client side JavaScript validation for free too).
You can always perform the validation in C# code in your Controller action like below:
public ViewResult BankPageAdd(BankPageModel model)
{
if(model.AccountRequired &&
(String.IsNullOrWhiteSpace(model.Account.AccountCode) || !Regex.IsMatch(model.Account.AccountCode, "PATTERN HERE"))
ModelState.AddModelError("NewAccount.AccountCode", "ERROR MESSAGE HERE");
//remainder of your controller action code here
}
And the javaScript version:
function validateAccountCode() {
var bCkd = document.getElementById("ckbxAccountRequired").checked;
if (bCkd) {
var accountCode = document.forms[0].elements["AccountCode"].value;
if(!accountCode.match(yourRegEx) || accountCode==""){
alert('Please fill in the Account Code');
return false;
}
return true;
}
return true;
}
Related
I have a model described as below:
public class Projet
{
public int ProjetId { get; set; }
public int SeqNumber{ get; set; }
public string Code{ get; set; }
public string Description { get; set; }
public bool Std{ get; set; }
public bool Archive { get; set; }
}
I have a create view to let a user create a new project, and I must let the SeqNumber field free so the user can input whatever number he wants.
However, I must return an error if the SeqNumber choosen is already taken.
I'm not sure how to implement this. Should I do some validation in my ProjetsController/Create action ? From what I can find, validating stuff in the controller is a bad practise, but I can't think of where to implement validation when it depends on other members of the same class.
Would coding a custom validator for MVC considered a good practise?
Thanks !
You can use this in your http post action method which handles the form submit
[HttpPost]
public ActionResult Create(Projet model)
{
var exist = db.Projects.Any(s=>s.SeqNumber===model.SeqNumber
&& s.ProjectId!=model.ProjectId);
if(exist)
{
ModelState.AddModelError(string.empty,"Sequence number is already in use");
return View(model);
}
// to do : Continue with your save
}
Now when user submits the form, if the sequence number is being used for any other project, it will throw a validation message. Make sure you are using the Validation summary helper in your view to render the validation error message.
#model Project
#Html.ValidationSummary(false)
#using(Html.BeginForm())
{
<!-- your existing code goes here-->
}
Now to give a nice user experience, you may take advantage of the Remote validation feature. What it does is, when user takes the focus out from the input, it makes an ajax call to server to check whether your SequenceNumber exist in db. Based on the result, the validation messages will be shown to the user.
To do this, decorate your property with the Remote attribute.
[Required]
[System.Web.Mvc.Remote("CheckSeqNumber", "Project",
ErrorMessage = "SeqNumber is already used!")]
public int SeqNumber { get; set; }
Now make sure you have an action method called CheckSeqNumber which returns either true or false as a json response.
public ActionResult CheckTagName(int SeqNumber)
{
var exist= !db.Projects.Any(g => g.SeqNumber == SeqNumber);
return Json(exist,JsonRequestBehavior.AllowGet);
}
Also make sure you have the relevant javascript files loaded to do this unobtrusive validation.
<script src="~/Scripts/jquery.validate.js"></script>
<script src="~/Scripts/jquery.validate.unobtrusive.js"></script>
Another option is to write a custom validation attribute which does this check for you (if you do not like that check in the action method). Here is an SO post explaining how to do it.
I've been googling like crazy without result, maybe I'm just missing the correct keywords.
I have a class with a custom validation attribute on a property. I want to "clean" the value before validation, removing the white-space and special characters that we accept but that we don't want to save to the database.
public class PersonViewModel
{
[SocialSecurityNumberLuhn(ErrorMessage = "Incorrect social security number")]
public string SocialSecurityNumber { get; set; }
}
I would want to do something like this:
public class PersonViewModel
{
[CleanWhiteSpace]
[SocialSecurityNumberLuhn(ErrorMessage = "Incorrect social security number")]
public string SocialSecurityNumber { get; set; }
}
For example 1985-03-15-1234 should be saved and validated as 19850315-1234.
Any suggestions? What's the neatest approach?
If you change the auto-implemented property into a manual-implemented property then you can perform the "cleaning" step when the value is set, so it can only be stored in the model in a "clean" state. Something like this:
public class PersonViewModel
{
private string _socialSecurityNumber;
[SocialSecurityNumberLuhn(ErrorMessage = "Incorrect social security number")]
public string SocialSecurityNumber
{
get { return _socialSecurityNumber; }
set
{
_socialSecurityNumber = CleanSocialSecurityNumber(value);
}
}
}
The recommended approach here is to use a service layer. View models should not include any logic. With a service layer Your controller would call a method on its associated service and this method would return your view model with the clean SSN.
In this tutorial you will see how the service layer can be structured and you could adapt the pattern to clean your data before validation.
http://www.asp.net/mvc/tutorials/older-versions/models-(data)/validating-with-a-service-layer-cs
The use of a ValidationAttribute in your example would be an incorrect usage also.
Controller where you would inject / instantiate the service class
public ActionResult GetPerson(int PersonId){
return _personService.GetPerson(personId);
}
The service method
public PersonViewModel GetPerson(int Id){
// get the data (maybe from DAL) and clean returning view model
return new PersonViewModel(){SocialSecurityNumber = Clean(...)};
}
Hope this gives you some direction.
I'm new at ASP.NET MVC web framework. My database is compound of a single model class("Movie"). I need to validate user's from entering existing data, for instance, a database row could be:
Title - "Indiana Jones and the lost Arc"
Price - $10.00
If another user tries to insert into the database the same data above, provide an error message and prevent from submitting the form collection.
First of all, I think that your question need a "program as answer" but I'll try to suggest you from where to start for working with validation. Suppose you have this model:
class Movie {
public Guid Id { get; set; }
[Required(ErrorMessage="Title is required.")]
[Remote("UniqueTitle", "Validation")]
public String Title { get; set; }
[Required(ErrorMessage="Price is required.")]
public float Price { get; set; }
}
You can decorate it for "simple validation" using Data Annotation. I've used a specific attribute, called Remote.
This attribute allow you to define a custom, server-side, logic to validate the model.
Now, you can create a validation controller where check that provided value is not already in use:
class ValidationController : Controller {
private IDbContext db = ...;
public ActionResult UniqueTitle(String title) {
var item = db.Movies.FirstOrDefault(m => m.Title.Equals(title));
return Json(item == null, JsonRequestBehavior.AllowGet);
}
}
Now you are ready to validate your model.
I hope this can help.
I'm wanting to check if I can send a message from a Model to a Controller, I'll explain.
So I have a Model
public class Car()
{
public int Id { get; set; }
public string Make { get; set; }
}
So when a user adds a new Car, I could make it required by using Fluent API or the [Required] annotation.
But what if I wanted to make sure I had only certain characters in there, so I wouldn't want the percentage symbol in there (unless there are any cars out there?!).
So I thought I'll use a constructor:
public class Car()
{
public Car(string _name)
{
if(this.Make.Contains("%"))
{
//Let the user know this isn't valid there is an error
}
}
public int Id { get; set; }
public string Make { get; set; }
}
I usually place the error logic in the Controller. So I would have
public ActionResult AddCar(Car car)
{
if(car.Make.Contains("%"))
{
//let user know this is not valid
}
if(ModelState.IsValid)
{
}
///
}
But then I thought, I'm never going to want to have a car Make with a % sign (I've picked on % sign, but actually there is a host of validation I would use, such as a list containing invalid characters), and every place in which I allowed for a user to add a car, I would duplicate the validation code, which just felt inefficient.
Maybe producing a the error checking in the controller is the correct way?
Again for clarity. The question, is there a way to pass a message from a Model to a Controller, which I can then pass to the User's view?
Kind regards
You should not use validation logic in your controller, we have DataAnnotations which allows us to validate model's properties value.
for your purpose you can use RegularExpression validator for this.
Refer to this Link for more details
I am working on asp.net mvc 2 web application.
I have model with 3 properties:
[IsCityInCountry("CountryID", "CityID"]
public class UserInfo
{
[Required]
public int UserID { get; set; }
[Required]
public int CountryID { get; set; }
[Required]
public int CityID { get; set; }
}
I have one "required" property attribute, and one attribute on class level :
using System;
using System.ComponentModel;
using System.ComponentModel.DataAnnotations;
[AttributeUsage(AttributeTargets.Class, AllowMultiple = true, Inherited = true)]
public class IsCityInCountry : ValidationAttribute
{
public IsCityInCountry(string countryIDProperty, string cityIDProperty)
{
CountryIDProperty = countryIDProperty;
CityIDProperty = cityIDProperty;
}
public string CountryIDProperty { get; set; }
public string CityIDProperty { get; set; }
public override bool IsValid(object value)
{
var properties = TypeDescriptor.GetProperties(value);
var countryID = properties.Find(CountryIDProperty, true).GetValue(value);
var cityID = properties.Find(CityIDProperty , true).GetValue(value);
int countryIDInt;
int.TryParse(countryID.ToString(), out countryIDInt);
int cityIDInt;
int.TryParse(cityID.ToString(), out cityIDInt);
if (CountryBusiness.IsCityInCountry(countryIDInt, cityIDInt))
{
return true;
}
return false;
}
}
When I post the form on my view, and CountryID is not entered, in ModelState dictionary there's an error about that issue. Other attribute is ignored ("IsCityInCountry"). When I choose CountryID and CityID, which is not in selected country, I get appropriate validation message about that, and ModelState has another key (which is ""). I understand that advantage have property attributes and then class attributes. My question; is there any way to get all validation messages at the same time, no matter what kind of attributes are involved (class or property attributes)? Thanks in advance.
ASP.NET MVC won't perform class level validation if there are property level validation errors. Brad Wilson explains this in his blog post:
Earlier today, we committed a change to MVC 2 that converted the
validation system from Input Validation to Model Validation.
What this means is that we will always run all validators on an
object, if that object had at least one value bound into it during
model binding. We run the property-level validators first, and if all
of those succeed, we'll run the model-level validators.
I would recommend you to go ahead and checkout FluentValidation.NET if you want to perform some more advanced validation in an ASP.NET MVC application. Declarative validation simply doesn't fit the bill in advanced validation scenarios.