Update timeout API to use new status code

Rather than letting the timeout error escape the public API, we'll
catch it and return a new GenerateFragmentStatus code. This is in
response to feedback that having both status codes and errors led
to messier integrations.
3 files changed
tree: c9a666b62bfc634db96861726dda9237badd253b
  1. .github/
  2. demo/
  3. src/
  4. test/
  5. tools/
  6. .gitignore
  7. .prettierignore
  8. .prettierrc
  9. CONTRIBUTING.md
  10. karma.conf.js
  11. LICENSE
  12. package-lock.json
  13. package.json
  14. README.md
README.md

Text Fragments Polyfill

This is a polyfill for the Text Fragments feature for browsers that don't support it directly.

The implementation broadly follows the text-finding algorithms, with a few small deviations and reorganizations, and should perform similarly to renderers which have implemented this natively. It is used in Chromium for iOS as well as the Link to Text Fragment Browser Extension.

The src directory contains three files:

  • text-fragments.js, containing the polyfilling mechanism.

  • text-fragment-utils.js, a module of util functions related to parsing, finding, and highlighting text fragments within the DOM. Most of the logic used by the polyfill for finding fragments in a page lives here.

  • fragment-generation-utils.js, a module of util functions for generating URLs with a text fragment. These utils are not used by the polyfill itself, but they are likely to be useful for related projects.

The tools directory contains a util script used for generating a regex used in the utils module.

The test directory contains unit tests, based on Karma and Jasmine, as well as HTML files which can be loaded during those tests.

Installation

From npm:

npm install text-fragments-polyfill

From unpkg:

<script type="module>
  if (!('fragmentDirective' in Location.prototype) &&
      !('fragmentDirective' in document)) {
    import('https://unpkg.com/text-fragments-polyfill');
  }
</script>

Usage

For simple usage as a polyfill, it is sufficient to import the text-fragments.js file:

// Only load the polyfill in browsers that need it.
if (
  !('fragmentDirective' in Location.prototype) &&
  !('fragmentDirective' in document)
) {
  import('text-fragments.js');
}

Users who wish to take a more hands-on approach can reuse chunks of the logic by importing the text-fragment-utils.js and fragment-generation-utils.js modules; support is provided for inclusion either as an ES6 module or using the Closure compiler.

Demo

Try the demo on a browser that does not support Text Fragments.

Development

  1. Hack in /src.
  2. Run npm run start and open http://localhost:8080/demo/ in a browser that does not support Text Fragments URLs directly, for example, Safari.
  3. Hack, reload, hack,…
  4. You can modify the Text Fragments URLs directly in /demo/index.html (look for location.hash).

License

Apache 2.0. This is not an official Google product.