A glossary panel for your site to help readers understand jargon
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Latest commit e8487b8 Jan 17, 2017 @noahmanger noahmanger 0.2.1
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Glossary panel

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Add a simple glossary panel to your site to help your users understand jargon-y terms. As seen on betaFEC and EITI.

For example:

Getting started

Note: if you are a contributor, please see CONTRIBUTING for additional help.


Via npm

npm install glossary-panel

Set up your HTML

The following is the bare minimum HTML needed in your document:

    <button class="js-glossary-toggle">Glossary</button>
    <div id="glossary" aria-describedby="glossary-title" aria-hidden="true">
      <button title="Close glossary" class="js-glossary-close">Hide glossary</button>
      <h2 id="glossary-title">Glossary</h2>
      <label for="glossary-search">Filter glossary terms</label>
      <input id="glossary-search" class="js-glossary-search" type="search" placeholder="e.g. Committee">
      <ul class="js-glossary-list"></ul>

It includes a toggle button, a div for the glossary, a close button inside the glossary, a title, a search input and label, and a <ul> for the terms.

Then, to add glossary terms to the body of the page, add a data-term attribute to the terms. For example:

A <span data-term="committee">committee</span> is a thing.

The data attribute must match the text of the term in your JSON file exactly, but it is not case-sensitive.


In whichever file you initialize your JavaScript components, initialize the glossary like so:

    var Glossary = require('@18f/glossary');

    // JSON file of terms and definitions
    var terms = require('terms');

    // Optional configurion objects
    var selectors = { ... };
    var classes = { ... };

    new Glossary(terms, selectors, classes);


The constructor expects an array of objects (terms) that follows this pattern:

    "term": "Glossary",
    "definition": "A useful tool for finding the definitions of terms"

The constructor also accepts an optional hash of selectors as its second parameter:

  • glossaryID: ID of the glossary panel that will be shown and hidden. Default: #glossary
  • close: ID or class of the close button inside the glossary panel. Default: .js-glossary-close
  • listClass: Class of the <ul> that will be populated with terms. Default: .js-glossary-list
  • searchClass: Class of the <input> that will be used to filter the list. Default: .js-glossary-search
  • toggle: ID or class of the element that will be used to open and close the glossary in the main body of the document. Default: .js-glossary-toggle

And you can pass an optional hash of classes to be applied to to the DOM:

  • definitionClass: Single class applied to the <div> that contains the term's definition. Default: glossary__definition
  • glossaryItemClass: Single class applied to the <li> that contains the term and deffinition. Default: glossary__item
  • highlightedTerm: Single class applied to terms in the body when they are highlighted. Default: term--higlight
  • termClass: Single class applied to the <button> element that opens the definition. Default: glossary__term


  • Glossary.show(): Show the glossary
  • Glossary.hide(): Hide the glossary
  • Glossary.toggle(): Toggle the glossary open or closed
  • Glossary.destroy(): Completely remove the glossary from the DOM
  • Glossary.findTerm(term): If the glossary is opens, filters the list down to the term called, expands the term, and highlights the associated term in the DOM


To style the glossary terms and defintions in the accordion list, either use the default classes or whichever ones you passed in. To change the style of the buttons when the accordion elements are expanded, you can select for [aria-expanded="true"].

You will need to add styles for [aria-hidden="true"] in order to hide the glossary panel and the glossary definitions.


Public domain

This project is in the worldwide public domain. As stated in CONTRIBUTING:

This project is in the public domain within the United States, and copyright and related rights in the work worldwide are waived through the CC0 1.0 Universal public domain dedication.

All contributions to this project will be released under the CC0 dedication. By submitting a pull request, you are agreeing to comply with this waiver of copyright interest.