HTML5 Element 'legend' occurs too few times

Question

I have the following View in MVC and I get the warning message: Validation (HTML5): Element 'legend' occurs too few times

@model Berwin.Models.ViewModels.UserViewModel

@{
ViewBag.Title = "Press";
}

<h2>Press Area</h2>

@using (Html.BeginForm("Register", "PressController", FormMethod.Post))
{
<fieldset>
    @Html.TextBoxFor(model => model.FullName)
</fieldset>

<fieldset>
    @Html.TextBoxFor(model => model.Company)
</fieldset>

<fieldset>
    @Html.TextBoxFor(model => model.EmailAddress)
</fieldset>

<fieldset>
    @Html.CheckBoxFor(model => model.JoinMailingList)
</fieldset>
}

Would like to know why I am getting this warning and what I need to do to fix this.

Answer 1

To prevent Visual Studio incorrectly warning you that the "Element 'legend' occurs too few times" you need to correct Visual Studio's HTML and XHTML validation files.

VS will then treat the <legend> tag as optional inside a <fieldset> tag (as per the spec).

To do so, there are two files you need to edit: html_5.xsd and xhtml_5.xsd. For VS2010 these are found in (e.g.):

C:\Program Files (x86)\Microsoft Visual Studio 10.0\Common7\Packages\schemas\html\

Steps to take:

1. Close Visual Studio

2. Using a text editor open the file html_5.xsd found in the folder above.

3. Locate the following line:

   (note there are two lines which are similar, the first is correct, the second needs editing):

   <xsd:element name="legend" type="legendType" minOccurs="1" maxOccurs="1" />

4. Edit the line to read:

   <xsd:element name="legend" type="legendType" minOccurs="0" maxOccurs="1" />

5. Save the file

6. Repeat the process for the file xhtml_5.xsd which is in the same folder

Now start Visual Studio and view your HTML5 file - the warning will be gone.

I hope that helps others, and I hope the .xsd files will be corrected in a future update.

UPDATE:

The line you need to find may be:

<xsd:element ref="legend" minOccurs="1" maxOccurs="1" vs:firstchild="true"/>

If so, change the minOccurs="1" attribute to minOccurs="0"

Answer 2

According the HTML 5 spec, the <legend> tag is not a required element within a <fieldset>.

The legend element represents a caption for the rest of the contents of the legend element's parent fieldset element, if any.

Docs: http://www.w3.org/TR/html5/forms.html#the-legend-element

In your case, its just a warning provided by Visual Studio or a plugin. Its not required and there may be a way to supress the warning under Tools - Options - Text Editor - HTML - Validation. Here you can also switch the target of your validation (HTML 5, XHTML 1, etc)

Answer 3

Legend is optional in a Fieldset.

But try this, to get rid of the warning:

    <fieldset>
        <legend>User</legend>
        @Html.TextBoxFor(model => model.FullName)
    </fieldset>