BUG: [Display(Prompt="...")] not working on textarea elements.

[Bartmax]

Model:

[DataType(DataType.MultilineText)]
[Display(Prompt =nameof(Issue))]
public string Issue { get; set; }

Using input:
placeholder attribute render correctly

<input asp-for="Issue" class="form-control" />

<input class="form-control" 
       type="text" 
       id="Issue" 
       name="Issue" 
       placeholder="Issue" 
       value=""
       data-val="" data-val-required="The Issue field is required."  />

Using textarea:
placeholder attribute missing from output

<textarea asp-for="Issue" class="form-control"></textarea>

<textarea class="form-control" 
          data-val="true" 
          data-val-required="The Issue field is required." 
          id="Issue" 
          name="Issue">
</textarea>

Expected:
Both textarea and input should have the placeholder attribute populated.

[dougbu]

A small feature gap. We implemented support for placeholder only in <input> elements i.e.DefaultHtmlGenerator.GenerateTextArea() lacks code we have in DefaultHtmlGenerator.GenerateInput().

[Haplois]

I implemented that, and pretty sure it works. But solution won't compile now, so I'm not sure. As soon as I can compile and test I'll send a pull request.

[Eilon]

@dougbu assigning to you for PR #4907.

[dougbu]

a852352