Oracle Fusion Middleware Tag Reference for Oracle ADF Faces 12c (12.2.1) E52774-02 |
Current accessibility standards (WCAG, 508) require that some mechanism be provided to allow keyboard users to skip over blocks of content that are repeated on all web pages, such as navigation links. The typical solution for meeting this requirement is to insert a "skip link" at the start of the page. The skip link allows the user to jump directly to the unique page content, thus saving both keyboard and screen reader users the trouble of traversing repetitive content.
Please note that some mobile platforms, like iOS, do not support browser keyboard navigation and have no concept of keyboard focus. On these platforms the skip link does not render. Usually on platforms like this the respective AT will allow AT virtual cursor navigation between page elements, and will meet the accessibility standards by providing ways to skip content by page element types or landmarks.
While it is possible for ADF Faces application developers to implement their own skip links using af:goLink, the af:skipLinkTarget tag simplifies this task. When the af:skipLinkTarget tag is present in an ADF Faces page, ADF Faces automatically creates a skip link at the start of the page. This skip link jumps to the first potentially focusable item for the specified skip link target. There is no need to manually insert an af:goLink or a target anchor.
Note that the focus moves to the first potentially focusable item for the specified skip link, and not the first tab stop. This is done for compatibility with screen readers, which follow focus. The first potentially focusable item could be a label or other useful text that the screen reader will read. A subsequent press of tab then brings focus to the next tab stop. For compatibility with screen readers, you should set your skipLinkTarget to be the first item or container of the main section of the page. This way the screen reader will read all the contextual information about the main section.
One of the advantages of the af:skipLinkSolution is that the skip link provided by ADF Faces is usually hidden from view. The skip link is automatically shown when it receives the focus (ie. when the end user tabs to the skip link, which is the first tab stop in the page), and is automatically hidden again as soon as the user activates the skip link or tabs to the next element. This approach avoids extra visual clutter in the chrome area of the page. There is no need to make extra room in the UI for the skip link content - it is displayed on demand.
Note that the af:skipLink tag has the following requirements:
Warnings are logged in the event that any of these requirements are not met. The easiest way to avoid these issues is to place the af:skipLinkTarget inside any of the ADF Faces panel components (inside of an af:document of course). Application developers are encouraged to specify the af:skipLinkTarget once in a page template, rather than attempt to add this individually to every page.
Name | Type | Supports EL? | Description |
---|---|---|---|
text | String | Yes | an optional value to use as the text of the skip link. If no value is specified a default value (eg. "Skip to contents") will be provided. |
accessibilityHint | String | Yes | NOTE: accessibilityHint is deprecated. ADF no longer supports a separate screen reader mode, as screen reader friendly content is provided in regular rich mode. Because of this, there is no longer a reason to have an accessibilityHint. |