ASP.NET MVC built-in helper for fields

Question

I need a common built-in helper to display fields.

Here is what I have:

@helper DisplayField(Func<MyModel, string> field)
{
    if (string.IsNullOrWhiteSpace(field(Model)) == false)
    {
        <div class="row"> @field(Model) </div>     
    }
}

Using:

@DisplayField(m => m.Name)
@DisplayField(m => m.PhoneNumber)

I do not know how to show the Label (DisplayAttribute) inside the helper. Please, help.

Answer 1

At the top of the page, add usage for System.Linq.Expressions, for example.

@using System.Linq.Expressions

(or add this namespace to web.config).

Then, to create an assistant, it will look something like this:

@helper DisplayField(Expression<Func<MyModel, string>> field)
{
    @Html.LabelFor(field)
    @Html.DisplayFor(field)
}

, .. , HtmlHelper, , "MyModel" "string", . , , . , :

@helper DisplayField<TModel, TValue>(Expression<Func<TModel, TValue>> field)
{
    @Html.LabelFor(field)
    @Html.DisplayFor(field)
}

, , HtmlHelper. :

• :

  using System;
  using System.Linq;
  using System.Linq.Expressions;
  using System.Web;
  using System.Web.Mvc;
  using System.Web.Mvc.Html;
  
  namespace MvcApplication1.HtmlHelpers
  {
      public static class HtmlHelpers
      {
          public static MvcHtmlString DisplayFieldFor<TModel, TValue>(
              this HtmlHelper<TModel> helper, 
              Expression<Func<TModel, TValue>> field)
          {
              var labelString = helper.LabelFor(field);
              var displayString = helper.DisplayFor(field);
  
              return MvcHtmlString.Create(
                  labelString.ToString() + 
                  displayString.ToString());
          }
      }
  }
  

• :

  @Html.DisplayFieldFor(m => m.Name)
  @Html.DisplayFieldFor(m => m.PhoneNumber)
  

... HtmlHelper web.config.

Answer 2

@David_001 MVC-; , , , MVC .

Func<MyModel, string> Expression<Func<MyModel, string>>. , , , .
:

var compExpr = field.Compile();
var value = compExpr.DynamicInvoke(Model);

, :

var memberAccExpr = (System.Linq.Expressions.MemberAccessExpression)field.Body;
var attr = (DisplayAttribute)memberAccExpr.Member.GetCustomAttributes(typeof(DisplayAttribute), false).FirstOrDefault();

# ( MVC), , Razor; , .
, , . , , .