Rewrite-css-urls NPM

rewrite-css-urls

This module is used to assist with rewriting URLs inside CSS code. It looks for URL patterns and provides convenience functions for replacing the URLs that were found.

To reduce complexity and code size, this utility does not use a fully CSS-compliant parser. In fact, the parser simply uses a couple of regular expressions and ignores comment blocks.

This utility searches for url(*) and @import "*" patterns specifically.

Installation

npm install rewrite-css-urls --save

Usage

Find

require('rewrite-css-urls').find(cssCode, function(urlRef) {
    console.log('Found URL: ' + urlRef.url);
});

Find & Replace

var transformedCssCode = require('rewrite-css-urls').findAndReplace(cssCode, {
    replaceUrl: function(urlRef) {
        return urlRef.url.replace('blah.com', 'mycompany.com');
    }
});

JavaScript API

The require('rewrite-css-urls') module exports the properties below.

Method: `findAndReplace(cssCode, options)`

Arguments:

Argument	JavaScript Type	Required / Optional	Description
`cssCode`	`String`	required	The raw CSS code
`options`	`Object`	required	Collection of options
`options.replaceUrl`	`Function(UrlRef)`	optional	This function will be called to replace all types of URLs and will be used when a more specific `options.replaceImportUrl` or `options. replaceAssetUrl` is not provided. Return `undefined` to not perform subsitution.
`options.replaceImportUrl`	`Function(UrlRef)`	optional	This function will be called to replace `@import "*"` URLs. Return `undefined` to not perform subsitution.
`options.replaceAssetUrl`	`Function(UrlRef)`	optional	This function will be called to replace `url(*)` URLs. Return `undefined` to not perform subsitution.

Returns:

String The transformed CSS code after URL substitutions.

Method: `find(cssCode, forEachFn)`

Argument	JavaScript Type	Required / Optional	Description
`cssCode`	`String`	required	The raw CSS code
`forEachFn`	`Function(UrlRef)`	required	Function that will be called for each URL

Type: `UrlRef`

Instances of UrlRef will be passed to the replaceUrl, replaceImportUrl, and replaceAssetUrl functions.

Property	JavaScript Type	Description
`url`	`String`	The actual URL
`start`	`Number`	Start character position
`end`	`Number`	End character position
`type`	`Number`	Either `require('rewrite-css-urls').UrlType.IMPORT_URL` (@import URL) or `require('rewrite-css-urls').UrlType.ASSET_URL` (image or font URL)