postcss-processor-splicer

!node

Allow your postcss plugin pipeline to be modified like an array.

Example

``javascript
var postcss = require('postcss')
var Pipeline = require('postcss-processor-splicer')

function createCreator(name) {
return function (opts) {
return function (root) {
root.append( { selector: opts && opts.name || name } )
}
}
}

var A = postcss.plugin('A', createCreator('a'))
var B = postcss.plugin('B', createCreator('b'))
var C = postcss.plugin('C', createCreator('c'))
var D = postcss.plugin('D', createCreator('d'))

var pipeline = new Pipeline([
A, // creator
B(), // plugin
postcss([C()]), // processor
new Pipeline([[D, { name: 'd' }]]), // pipeline
])

Promise.resolve()
.then(function () {
return pipeline.build()
.process('x{}')
.then(log.bind(null, 'apply all plugins: A, B, C, D'))
})
.then(function () {
return pipeline.build('B', 'C')
.process('x{}')
.then(log.bind(null, 'apply plugins B, C with default options'))
})
.then(function () {
return pipeline.build(['A', { name: '.a' }], ['D', { name: '.d' }])
.process('x{}')
.then(log.bind(null, 'apply plugins A, D with options (only valid for creators)'))
})
.then(function () {
pipeline.splice('B', 2)
return pipeline.build()
.process('x{}')
.then(log.bind(null, 'splice, delete B, C'))
})
.then(function () {
pipeline.unshift(B())
return pipeline.build()
.process('x{}')
.then(log.bind(null, 'unshift plugin B'))
})
.then(function () {
pipeline.push(C)
return pipeline.build()
.process('x{}')
.then(log.bind(null, 'push creator C'))
})
.then(function () {
pipeline.get('C').push({ name: '.c' })
return pipeline.build()
.process('x{}')
.then(log.bind(null, 'modify default options for creator C'))
})
.then(function () {
pipeline.pop()
return pipeline.build()
.process('x{}')
.then(log.bind(null, 'pop creator C'))
})
.then(function () {
pipeline.shift()
return pipeline.build()
.process('x{}')
.then(log.bind(null, 'shift plugin B'))
})
.catch(function (err) {
console.log(err)
})

function log(title, result) {
console.log('\n')
console.log('x'.repeat(40))
console.log(title, ':')
console.log(result.css)
}


`

output:

`
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
apply all plugins: A, B, C, D :
x{}
a{}
b{}
c{}
d{}


xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
apply plugins B, C with default options :
x{}
b{}
c{}


xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
apply plugins A, D with options (only valid for creators) :
x{}
.a{}
.d{}


xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
splice, delete B, C :
x{}
a{}
d{}


xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
unshift plugin B :
x{}
b{}
a{}
d{}


xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
push creator C :
x{}
b{}
a{}
d{}
c{}


xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
modify default options for creator C :
x{}
b{}
a{}
d{}
.c{}


xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
pop creator C :
x{}
b{}
a{}
d{}


xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
shift plugin B :
x{}
a{}
d{}


`

pipeline = new Pipeline(creators)

Create a pipeline of creators.

$3

Type: Array

Elements could be postcss plugins, postcss plugin creators, instances of Pipeline.
To set default options, just pass an array as the element.




$3

Modify the builtin creators.

ArrayLikeMethods could be one of the following:

* splice
* push
* pop
* shift
* unshift

$3

Get the internal representation of the creators according to the given plugin names or indexes.

#### creator
Representation of a creator.

Type: Array

The first element could be a postcss plugin function,
or postcss creator function (created with postcss.plugin).

Other elements are passed to the creator as options when build the plugin function.

#### postcssPlugin

Type: String, Number`

Plugin name, or indexes in the pipeline.

$3

Create a postcss processor from given creators,
or creators in the pipeline.

You can use the plugin name or index to specify the plugin.