Skip to content

Latest commit

 

History

History
155 lines (105 loc) · 11.2 KB

README.md

File metadata and controls

155 lines (105 loc) · 11.2 KB
Raw

Landmarks

Build Status

This is a browser extension (for Firefox, Chrome and Opera) that enables navigation of WAI-ARIA landmarks, via the keyboard or a pop-up menu.

Landmark regions broadly signpost the areas of a page (e.g. navigation, search, main content and so on). They can make navigation considerably easier for people who use the keyboard to navigate and those using assistive technologies such as screen-readers, because they make it much quicker to get an overview and to navigate to (and between) areas of interest.

If you're a web author/developer, check out the information below on why landmarks rock, and how easy they are to put into your site—in fact, if you're using HTML 5, you probably already have landmarks on your site, but there are some ways to make them even more helpful, as discussed below.

Table of contents

Installation and usage

Use the installation links on the home page to install the extension. When it's installed, you will find documentation on topics such as:

  • How to navigate by shortcut key, and how to change the shortcut keys.
  • How to navigate using the toolbar pop-up.
  • How to navigate using the sidebar (where supported).
  • Border preferences, for landmark highlights and labels whilst navigating.

The rest of this file provides information that may be of help and interest to web authors, designers and developers, accessibility testers and browser extension developers.

This extension's support for landmarks

The extension supports WAI-ARIA landmark roles, both as supplied via the role attribute and as implicit landmarks via HTML 5 elements. All landmark roles are supported, with some caveats, as per the relevant specifications, which are described below.

  • banner1
  • complementary
  • contentinfo1
  • form2
  • main
  • navigation
  • region2
  • search

Caveats

  1. Both <header> (banner) and <footer> (contentinfo) elements are not considered landmarks unless they are the page-wide header/footer elements. (As per the HTML element role mappings.)

  2. form and region landmarks are intended to be labelled. Ideally, this should be done with a visual label and an aria-labelledby attribute, so that all users can perceive the label. However, if a label is only provided by the non-visual aria-label attribute, this extension will recognise it.

    The HTML Accessibility API Mapping is clear that both unlabelled <form> and unlabelled <section> (region) elements are not to be counted as landmark regions. This extension discounts any unlabelled element with a role of form or region too, which is in line with most assistive technologies, and is intended to reduce noise in landmark navigation.

Labelling landmarks

If a landmark label is present (via the aria-labelledby or aria-label attributes), it'll be shown in the pop-up. As per the accessible name calculation algorithm used by browsers, the aria-labelledby attribute takes precedence over aria-label.

If an aria-labelledby attribute references multiple elements, all of those elements' text content will be joined to form the label for the landmark. However, it's not recommended that you label landmark regions with more than one element (usually referring to a single HTML heading element is sufficient). Using more than one labelling element could be a sign that your landmark structure is too complicated. Referencing multiple labelling elements is more suited for labelling <input> elements with information from multiple sources.

Digital publishing ARIA landmarks

The following additional landmark roles defined in the Digital Publishing WAI-ARIA Module 1.0 are also supported.

  • doc-acknowledgements
  • doc-afterword
  • doc-appendix
  • doc-bibliography
  • doc-chapter
  • doc-conclusion
  • doc-credits
  • doc-endnotes
  • doc-epilogue
  • doc-errata
  • doc-foreword
  • doc-glossary
  • doc-index (is a landmark via navigation)
  • doc-introduction
  • doc-pagelist (is a landmark via navigation)
  • doc-part
  • doc-preface
  • doc-prologue
  • doc-toc (is a landmark via navigation)

Information for web authors, designers and developers

As described at start of this document, landmarks can really help various people get a quick overview of your site, and navigate it much more effectively. This can save them a lot of time, so please consider implementing landmarks on your site; here is some information to help you do so...

Please bear in mind the following when implementing landmarks...

  • It's important that landmarks are not over-used, because their power comes from providing a concise overview of the content of the page. The heading hierarchy for the page can be relied upon for more fine-grained navigation within a particular area of a page.

    Rule of thumb: Use as few landmarks as possible, but ensure that all of the content on the page is within a landmark region.

  • If you're using HTML 5 elements such as <header>, <nav>, <main> and others, then your page will inherit some landmarks automagically. However it can be really helpful to label them (especially if there's more than one landmark of the same type on a page, such as a separate site-wide and page-local <nav>). The W3C documentation has all the details, but essentially you would use either the aria-labelledby or aria-label attribute.

    Rule of thumb: If you've more than one landmark of the same type, then be sure to label them, so their purpose is clear.

Development

You can build and run the current code locally as follows.

  1. Clone the Landmarks repository on GitHub to your computer.

  2. Ensure you have all the required build tools with npm install (you will need Node.js).

  3. Run the build script to build one or all of the extensions:

    • npm run build:firefox
    • npm run build:chrome
    • npm run build:opera
    • npm run build:edge (Edge support is in development, but not fully ready yet.)
    • npm run build:all

    The built versions of the extension are placed in the build/<browser>/ directories and ZIP files for each will be created in the root of the checked-out repository.

  4. To load and use the extension locally in your browser...

Some further info on the test/build process:

  • Automated tests are run as a pre-requisite part of the build process; you can also run them with npm test.

  • You can remove the build/<browser>/ directories and ZIP files with npm run clean:<browser> and npm run clean:all, as with the build scripts above.

  • Because the process of rasterising the SVG to variously-sized PNGs is slow, the PNGs are cached so they only need to be re-generated when the SVG changes. You can clean out the cache with npm run clean:cache.

  • The pre-commit hook is used to ensure only code that passes tests is committed (it does this by running a build, which, in turn, runs the tests). Husky manages this so that a build is run before you are asked for a commit message.

  • The build:chrome:test script is provided for making an alpha/beta/test build for Chrome, which is the same as a normal build, but the extension is retitled to "Landmarks (test version)". A separate extension listing is required for publishing test versions in the Chrome Web Store. For Firefox Add-ons, a version number such as "2.1.0beta1" can be used and the built package can be uploaded to the extension's beta channel.

Test pages

The following pages are incorporated into the automated test suite, but you can also visit them in-browser to try out the extension's UI.

Acknowledgements

This is a fork of the original landmarks extension written by davidtodd at IBM. Thanks to stevefaulkner for suggesting I work on this, and for feature suggestions (and again to davidtodd for supporting me doing so), and to The Paciello Group for donating a significant chunk of the initial development time.