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X-Tag - Rocket fuel for component development

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NPM version


This is the repository for the core X-Tag library.

X-Tag is a Microsoft supported, open source, JavaScript library that wraps the W3C standard Web Components family of APIs to provide a compact, feature-rich interface for rapid component development. While X-Tag offers feature hooks for all Web Component APIs (Custom Elements, Shadow DOM, HTML Templates), it only requires Custom Element support to operate. In the absence of native Custom Element support, X-Tag relies on the same set of polyfills Google's Polymer framework uses.

You can find out more about what X-Tag does, where it works, and how to use it, on the project page:

Snag X-Tag from NPM

npm install x-tag

Pull our repo from Github

To get started hacking on X-Tag core:

git clone x-tag-core --recursive
cd x-tag-core
npm install        # installs all the required dependencies using package.json
gulp all     # outputs x-tag-core.js and x-tag-core.min.js to ./dist


If you already cloned the library and want to update your build with changes to Core, do:

cd x-tag-core
git pull origin master
npm install
gulp all

This assumes you just cloned the library and its remote repository is labelled origin. Suppose you had your own fork where your own remote is origin; you should add another remote origin and label it as upstream. Then your git pull line would need to be git pull upstream master instead.


We use Jasmine to test the library, and you can verify it works as expected by opening tests/core/index.html in your browser to run the tests.

Regenerating the distributable build

In the interest of not reinventing the wheel, X-Tag core uses a few existing libraries which get pulled into the project. But distributing a bunch of separate files is not efficient, so we need to generate a single file that contains all this code.

If you make changes on the library and want to regenerate the build, just run

gulp all

and both x-tag-raw.js and x-tag-polyfilled.js will be rebuilt, minified, and placed in the ./dist directory.

Creating your own Web Components

To learn more about X-Tags visit