tarqd / launchdarkly-html-sdk

Use LaunchDarkly feature flags with the internet's most popular programming language

LaunchDarkly HTML SDK

A module for controlling browser HTML with LaunchDarkly feature flags. It can be included in an HTML page without having to write any additional Javascript.

Motivation

At last, LaunchDarkly support for the internet's most popular programming language.

With the addition of the LaunchDarkly HTML SDK, you can use feature flags to:

• add or remove CSS classes
• change the text content
• change an attribute value

... in any HTML element in the page, without writing Javascript. (But Javascript support is still required.)

This module is based on the LaunchDarkly Javascript SDK.

Examples

<!-- Adds the "blue-bg" class to this element
    when the "blue-panel" flag evaluates to true 
-->
<div data-ld-key="blue-panel" data-ld-addclass="blue-bg"></div>

<!-- after successful connection to LaunchDarkly or a proxy, this
    will evaluate the "h1-content" flag and replace the
    current inner text with the result; otherwise, the existing
    inner text will remain
-->
<h1 data-ld-key="h1-content" data-ld-innertext>Old Heading<h1>

Usage

Add the module to your page using a <script> tag. Note the addition of the data-ld-clientkey attribute.

<script src="launchdarkly-html-sdk.js" data-ld-clientkey="ADD YOUR CLIENT KEY HERE"></script>

Once loaded, the SDK will attempt to make a connection to the LaunchDarkly servers. After the connection is complete, all data-ld attributes in the page will be evaluated and their elements updated. There will be further updates as events warrant.

Known Issues

No user/context object

There are plenty of possible ways to do this, not just in the page; it may be useful for site cookies to be included.

No support for multiple projects or environments