BrowserValidationEngine.cs :  » Content-Management-Systems-CMS » Cuyahoga » Cuyahoga » Core » Validation » C# / CSharp Open Source

using System;
using System.Text;
using Castle.Components.Validator;
using Cuyahoga.Core.Validation;

namespace Cuyahoga.Core.Validation{
  /// <summary>
  /// Responsible for generating client-side validation scripts.
  /// </summary>
  public class BrowserValidationEngine
  {
    private ILocalizedValidatorRegistry _validatorRegistry;
    private IBrowserValidatorProvider _browserValidatorProvider;

    /// <summary>
    /// Creates a new instance of the <see cref="BrowserValidationEngine"></see> class.
    /// </summary>
    /// <param name="validatorRegistry">The validator registry where the validators are obtained.</param>
    /// <param name="browserValidatorProvider">The provider that generates client script for the validators.</param>
    public BrowserValidationEngine(ILocalizedValidatorRegistry validatorRegistry, IBrowserValidatorProvider browserValidatorProvider)
    {
      _validatorRegistry = validatorRegistry;
      _browserValidatorProvider = browserValidatorProvider;
    }

    /// <summary>
    /// Generates a client-side validation script based on the attributes of the modelToValidate.
    /// </summary>
    /// <param name="modelToValidate">The model to validate.</param>
    /// <param name="formId">The client ID of the form.</param>
    /// <param name="propertyNameToElementId">Delegate that can translate properties of the model to form elements.</param>
    /// <returns></returns>
    public string GenerateClientScript(object modelToValidate, string formId, Func<string, string> propertyNameToElementId)
    {
      // Create a BrowserValidationConfiguration instance to store all validation rules.
      BrowserValidationConfiguration config = this._browserValidatorProvider.CreateConfiguration(null);
      // Create a ValidatorRunner that is needed to obtain the validators for the given modelToValidate.
      var validatorRunner = new ValidatorRunner(this._validatorRegistry);
      // Create a script generator and that is linked to the BrowserValidationConfiguration
      IBrowserValidationGenerator generator = 
        _browserValidatorProvider.CreateGenerator(config, InputElementType.Undefined, propertyNameToElementId);
      // Get all validators for the given modelToValidate
      IValidator[] validators = 
        _validatorRegistry.GetValidators(validatorRunner, modelToValidate.GetType(), RunWhen.Everytime);
      // Iterate the validators and call ApplyBrowserValidation to generate the validation rules and messages into the BrowserValidationConfiguration.
      foreach (var validator in validators)
      {
        validator.ApplyBrowserValidation(config, InputElementType.Undefined, generator, null, propertyNameToElementId(validator.Property.Name));
      }

      // Generate the validation script block
      var sb = new StringBuilder();
      sb.Append("<script type=\"text/javascript\">" + Environment.NewLine);
      // Call CreateBeforeFormClosed of the BrowserValidationConfiguration. This generates the client script. 
      // Note: it's called CreateBeforeFormClosed because originally (in Monorail), it was used to only 
      // generate some extra scripts for validation.
      sb.Append(config.CreateBeforeFormClosed(formId));
      sb.Append("</script>" + Environment.NewLine);
      return sb.ToString();
    }
  }
}