50 lines
1.9 KiB
C#
50 lines
1.9 KiB
C#
using System;
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using System.Linq.Expressions;
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using System.Web.Mvc;
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namespace LeafWeb.WebCms.Utility
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{
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public static class Validation
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{
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/// <summary>
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/// Checks the ModelState for an error, and returns the given error string if there is one, or null if there is no error
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/// Used to set class="error" on elements to present the error to the user
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/// </summary>
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/// <typeparam name="TModel"></typeparam>
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/// <typeparam name="TProperty"></typeparam>
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/// <param name="htmlHelper"></param>
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/// <param name="expression"></param>
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/// <param name="error"></param>
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/// <returns></returns>
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public static MvcHtmlString ValidationErrorFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, string error)
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{
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if (HasError(htmlHelper, ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData),ExpressionHelper.GetExpressionText(expression)))
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return new MvcHtmlString(error);
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else
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return null;
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}
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private static bool HasError(this HtmlHelper htmlHelper, ModelMetadata modelMetadata, string expression)
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{
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string modelName = htmlHelper.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldName(expression);
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FormContext formContext = htmlHelper.ViewContext.FormContext;
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if (formContext == null)
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return false;
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if (!htmlHelper.ViewData.ModelState.ContainsKey(modelName))
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return false;
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ModelState modelState = htmlHelper.ViewData.ModelState[modelName];
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if (modelState == null)
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return false;
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ModelErrorCollection modelErrors = modelState.Errors;
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if (modelErrors == null)
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return false;
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return (modelErrors.Count > 0);
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}
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}
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}
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