Remove the @helper directive from Razor

[pranavkm]

At this point, the design for the @helper directive seems incomplete vis-a-vis

1. support for async code
2. support for Helper files that could be placed under App_Code

Based on design discussion for aspnet/Mvc#1130, the current thought is to remove the @helper feature until we come up with a better design for these questions.

[ajaybhargavb]

b3c6097

[alexaku-zz]

@Helper is a simple construction that intended for frequent use in place. @Helper is not intended for an async code embedding or a detached code use. It is useful when we need to define tiny portion of the parameterized html-code inside the View-file and reuse it inside the same View-file. The most meaningful thing is direct access to a Model from @Helper. In other words, helper is a simple context-related part that completely depended on a concrete View-file. Delete of this functionality is a hooliganism.

[ateregulov]

Implementation of the ViewComponents turned out horrible.

[alexaku-zz]

@pranavkm, @ajaybhargavb, @yishaigalatzer
You have provided us with TagHelpers that are going to be added to ASP.NET MVC 6 (RTM), basically to replace @helpers. Each tag helper is a new separate file (class). Furthermore, each of these separate file can't contain an HTML markup (Razor). There are only C# or VB code. If you remember ViewComponents, there will be appear even two files. How can I reuse some portion of the simple HTML code in my View without adding a bunch of extra files? If you retain the @functions in the Razor despite deletion of the @Helper, than you must add HTML markup feature in their bodies. See below two @functions that could perform the same code.

@functions {

public HtmlString GetTableHeader1(String className)
{
HtmlString result = <text>
<tr class="@className">
<td title="abc">one</td>
<td title="xyz">two</td>
</tr>
</text>;
return result;
}

public HtmlString GetTableHeader2(String className)
{
HtmlString result = new HtmlString(@"
<tr class=""" + Html.Encode(className) + @""">
<td title=""abc"">one</td>
<td title=""xyz"">two</td>
</tr>
");
return result;
}

}