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)