aria-required属性学习笔记

网址：https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/ARIA_Techniques/Using_the_aria-required_attribute

The aria-required attribute is used to indicate that user input is required on an element before a form can be submitted. This attribute can be used with any typical HTML form element; it is not limited to elements that have an ARIA role assigned.

aria-required属性用于表明在一个form被提交之后，form里包含的某个元素需要用户输入。该属性不仅限于具有ARIA role属性赋值的元素，任何form内能够包含的典型element都能够维护该属性。

HTML5 now has the required attribute, but aria-required is still useful for user agents that do not yet support HTML5.

虽然HTML5现在已经支持原生的required属性了，但是对于那些尚无法支持HTML5的user agent来说，aria-required仍然非常有用。

Screen readers should announce the field as required.

Note that this attribute will not automatically change the presentation of the field.

该属性并不会改变元素的视觉外观。