input-button-non-empty-value

Forbid <input type="button"> from carrying value="". The HTML Living Standard does not state this constraint verbatim — the Button state section §4.10.5.1.21 only describes that the UA renders the value attribute as the button label and supplies a default when the attribute is missing. The "must not be the empty string" assertion is hard-coded by nu-validator's schematron-equiv assertions (search for must have non-empty attribute "value"). nu reports this as an error; this rule mirrors that conformance signal but takes the conservative stance — it fires only on the explicit value="" case and leaves missing-value handling alone (the spec text permits omission).

❌ Examples of incorrect code for this rule

<input type="button" value="" />

✅ Examples of correct code for this rule

<input type="button" value="OK" /> <input type="button" />

Interface

{
  "input-button-non-empty-value": boolean
}

Forbid an empty value attribute on <input type="button"> elements; if specified the value must be non-empty.

Default Severity

error