id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
31012	Required SelectDateWidget renders invalid HTML	Kevin Brown	nobody	"When you render a `SelectDateWidget` for a field marked as required, I noticed it produced output that does not meet the HTML standard per https://www.w3.org/TR/html5/sec-forms.html#placeholder-label-option. This was called out in the 3.0 release notes so I checked out #29056 and determined that was likely the cause.

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The specific issue is that a `SelectDateWidget`, when specified as a required field, will generate a `placeholder` attribute on each of the `<select>` boxes which it generates. The `placeholder` attribute is not valid for a `<select>` box and instead a ""placeholder"" option must be specified as an `<option>` with an empty value (`value=""""`) with the text containing the placeholder to display.

From a Django forms perspective, this would be equivalent to setting the `empty_label` for the `SelectDateWidget` to `(_('Year'), _('Month'), _('Day'))`, which would generate each of the placeholder label options for each of the corresponding `<select>` boxes used by the widget.

It's also important to note that the HTML generated for the `SelectDateWidget` in previous versions of Django was valid per the HTML standard. They did not contain a placeholder label option, but because they were not a `<select multiple>` they always contained an option with a selectedness set to true (usually the first option). This meant that the `required` attribute generated for them was useless, since it would never not have a value or be empty, but it did mean it was still valid HTML.

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Here's some relevant parts of the standard when it comes to required select boxes.

> If a select element has a required attribute specified, does not have a multiple attribute specified, and has a display size of 1; and if the value of the first option element in the select element's list of options (if any) is the empty string, and that option element's parent node is the select element (and not an optgroup element), then that option is the select element's placeholder label option.
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> If a select element has a required attribute specified, does not have a multiple attribute specified, and has a display size of 1, then the select element must have a placeholder label option.
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> Constraint validation: If the element has its required attribute specified, and either none of the option elements in the select element's list of options have their selectedness set to true, or the only option element in the select element's list of options with its selectedness set to true is the placeholder label option, then the element is suffering from being missing.

You can also find the list of accepted attributes for a `<select>` at https://html.spec.whatwg.org/multipage/form-elements.html#the-select-element and https://developer.mozilla.org/en-US/docs/Web/HTML/Element/select#Attributes. Note that neither of those pages specify that a `<select>` element may have a `placeholder` attribute."	Bug	closed	Forms	3.0	Release blocker	fixed		Hasan Ramezani	Accepted	1	0	0	1	0	0