# Update Externals Plugin #

## Introduction ##

The update externals plugin allows for updates to html files that need to
reference external resources generated by lumbar.

## Usage ##

The update externals plugin will automatically execute on any static files with
the *.html* or *.htm* extensions. This can be disabled by adding `"update-externals": false`
to the resource. Execution on files with other extensions can be enabled by
`"update-externals": true` on the desired resource.

When enabled the plugin will update any `<script>` and `<link>` elements that reference
modules in the form of `module:${name}` where `${name}` is the name of the module to
reference.

Combined modules may be loaded by setting the `href` or `src` attribute to any module
reference within the combined package.

Note that this plugin is required to use [lumbar-loader](https://github.com/walmartlabs/lumbar-loader)
as this configures the `lumbarLoadPrefix` variable.

## Example ##

For a html file with the following elements,

    <link rel="stylesheet" type="text/css" href="base.css">
    <link rel="stylesheet" type="text/css" href="module:base">
    <script type="text/javascript" src="base.js"></script>
    <script type="text/javascript" src="module:base"></script>

update-externals will generate the following output

    <link rel="stylesheet" type="text/css" href="base.css">
    <link rel="stylesheet" type="text/css" href="/r/phoenix/web/base.css">
    <script type="text/javascript" src="base.js"></script>
    <script type="text/javascript">var lumbarLoadPrefix = '/r/phoenix/web/';</script>
    <script type="text/javascript" src="/r/phoenix/web/base.js"></script>