postcss-helpers

postcss-helpers

Some general purpose helpers for PostCSS, created to make working with url() and @import values more easy. Can be used without PostCSS.

Getting Started

npm install postcss-helpers

Helpers

#createUrlsHelper( rule )

Returns new UrlsHelper object from the rule string with one or more url() (see description below).

#createImportHelper( rule )

Returns new ImportHelper object from the @import value string (see description below).

new UrlsHelper( rule )

Object for manipulating values of rules with one or multiple url().

#getOriginalRule

Returns original rule that it was created with.

#getOriginalURIS

Returns Array of all original URI in string. NOT mutated URIs.

#URIS

Array of one or more urijs objects that can be used for URI manipulations. If there is no url() in the rule returns false.

For example you can use UrlsHelper.URIS[0].href() to get value for the first url() and UrlsHelper.URIS[0].href('new_uri') to set new URI value. See full documentation.

#getModifiedRule

After you finished changing values of the URIS you can get modified rule text with this command.

new ImportHelper( rule )

Object for manipulating values of @import at-rules.

#getOriginalRule

Returns original rule that it was created with.

#getOriginalURI

Returns original URI from string. NOT mutated URI.

#URI

urijs objects that can be used for URI manipulations. If there is no url() in the rule returns false.

For example you can use ImportHelper.URI.href() to get import value and ImportHelper.URI.href('new_uri') to set new URI value. See full documentation.

#getModifiedRule

After you finished changing values of the URI you can get modified rule text with this command.

#getOriginalMediaQuery

Returns media query from original string.

#setMediaQuery( query )

Replace old media query or creates new one.

#getMediaQuery

Returns current media query from string.

Other

#regexp

Collection of some useful RegExps based on CSS specification grammar rules: http://www.w3.org/TR/CSS21/grammar.html

• STRINGS – RegExp for css <string> with 'ig' flags.
• URLS – RegExp for css <uri> with 'ig' flags.

Examples

Modify string with multiple url() fragments:

var helpers = require( 'postcss-helpers' );

var rule = 'url(logo1.png)', url( 'logo2.png' ), url( "logo3.png");

var helper = helpers.createUrlsHelper( rule );

helper.URIS.forEach( function( uri ) {
    uri.suffix( 'jpeg' );
} );

var modifiedRule = helper.getModifiedRule(); // url(logo1.jpeg)', url( 'logo2.jpeg' ), url( "logo3.jpeg")

Modify @import value:

var helpers = require( 'postcss-helpers' );

var rule = '"src/print.css" print';

var helper = helpers.createImportHelper( rule );

helper.URI.directory( 'dist' );
helper.getMediaQuery(); // print
helper.setMediaQuery( 'screen' );

var modifiedRule = helper.getModifiedRule(); // "dist/print.css" screen

Test if string contains url() fragments:

var helpers = require( 'postcss-helpers' );

var rule = 'url(logo1.png)', url( 'logo2.png' ), url( "logo3.png");

helpers.regexp.URIS.test( rule ); // true

Known problems

UrlsHelper() and ImportHelper() will not escape quotes in the new URI values so escape them yourself.

Release History

See CHANGELOG for detailed changes.

• 2014-08-08   0.1.0   Initial release.
• 2014-08-11   0.1.1   Make RegExps public. Fixed ?#iefix bug.
• 2014-08-12   0.2.0   Added methods for getting original url() values and for media query manipulations.