procss

Procss

Plugins-based CSS post-processor to modify CSS with JavaScript.

It uses /* procss.<command_name>([<command_params>...]) */ CSS comments to to run processors <command_name> handlers in the relative context.

So, Procss allows you to use specific processors for specific cases.

It uses PostCSS to parse CSS and provide a usable JS API to edit CSS node trees.

Usage

Install with npm:

    $ [sudo] npm install procss --save

If you want to use procss on your cli install with:

    $ [sudo] npm install procss -g

CLI

Usage:

    $ procss [OPTIONS]

Options:

    -h, --help : Help
    -v, --version : Version
    -i INPUT, --input=INPUT : Glob string(s) or file path(s) to process, "-" for STDIN
    -o OUTPUT, --output=OUTPUT : Output file, "-" for STDOUT, by default '?.pro.css'
    -p PLUGINS, --plugins=PLUGINS : Plugins to use.

Arguments:

    INPUT : Alias to --input

Example:

• with files:

    $ procss test.css -p pluginName

or
 
    $ procss test.css -o ?.processed.css -p pluginName
    
or
    
    $ procss test.css test2.css -o ?.processed.css -p pluginName
    
or
    
    $ procss '*test*.css' -o ?.processed.css -p pluginName

• with STDIN / STDOUT:

    $ cat test.css | procss -i - -o - -p pluginName > ?.processed.css

JS API

Usage:

require('procss')
    .run(options)
    .then(cb);

Options:

• input: Glob string(s) or file path(s) to process, "-" for STDIN
• output: Output filepath mask [?.pro.css]
• plugins: Plugins to use

Example:

require('procss')
    .run({
        input : '*test*.css',
        output : '?.processed.css',
        plugins : [ 'pluginName', 'pluginPath/pluginName' ]
    })
    .then(cb);

Configuration

You can predefine options in .procss.js config files like this:

module.exports = {
    output : 'changed_?.css',
    plugins : [ 'some-plugin' ]
}

'?' in output is an input file name mask.

Proccs uses the nearest to input file config, so it will try to find .procss.js in each folder from input path to root.

If you want to define configs depending on the input file path, you can use wildcard patterns:

module.exports = [
    {
        file_paths : 'dirA/**/*.css',
        config : {
            output : 'changed_?.css',
            plugins : [ 'some-plugin' ]
        }
    },
    {
        file_paths : [ 'dirA/a.css', 'dirB/*.css' ],
        config : {
            output : 'changed-once-more_?.css'
        }
    }
]

Each matched config will extend the previous one, so for /dirA/a.css input file it will be:

{
    output : 'changed-once-more_?.css',
    plugins : [ 'some-plugin' ]
}

Plugins can be defined by npm package name and/or by absolute or relative to config path:

module.exports = {
    'plugins' : [ 'some-plugin"', 'my-super-plugin/plugin.js' ]
}

Plugins are processed in order, so definition order is significant.

Plugins can also have their own configs:

[
    {
        file_paths : 'dirA/**/*.css',
        config : {
            plugins : [
                {
                    plugin : 'some-plugin',
                    config : { 'some-prop' : 'some-val' }
                }
            ]
        }
    },
    {
        file_paths : [ 'dirA/a.css', 'dirB/*.css' ],
        config : {
            plugins : [
                {
                    plugin : 'some-plugin',
                    config : { 'some-prop' : 'some-another-val' }
                },
                {
                    plugin : 'my-super-plugin/plugin.js',
                    config : { 'some-another-prop' : 'some-another-val' }
                }
            ]
        }
    }
]

Plugins

List of plugins

Plugins development

Plugin is a simple Node.js module, which must export object with at least one API methods:

before - will be called before start to process input files.

beforeEach - will be called before start to process commands in file.

process - will be called to process each parsed command.

afterEach - will be called after finish to process file.

after - will be called after finish to process files.

@todo

Plugin example