cssy
v2.2.1
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A browserify transform for css (with vitamines)
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cssy
A browserify transform for css (with vitamins): Use css sources like any other module but without forgo the benefits of pre-processing and live source reload.
var myCss = require('foo/my.css')
myCss() // Inject the css in document
myCss(elsewhere) // To inject css elsewhere
myCss(elsewhere, 'tv') // Media query...
myCss.update('h1 { }') // Update source for all injected instances
myCss.onChange(function(css) { }) // Watch for change (hey, you like live source reload ?)
console.log('Source: %s', myCss) // Use as a string
See exemple with cssy, htmly and lrio
Features
- Require css as any other commonjs module:
require('foo/common.css')
. - Pre/post processing: Cssy is framework-agnostic:
- Use any post/pre-processor you like (rework, postcss, less, sass, etc.)
- At package level, you encapsulate your css secret cooking and export only standard css.
- At application level you can do global processing for things like global
url()
rebasing.
- A nice API to read, insert, update or remove: Use the exported css wherever you want and as you like.
- @import: If enabled, the css at-rule @import
require()
and inject another css module for you. - Source map: If enabled, cssy inject a source map.
- Live source reload: Provide a simple http(s) server hook reload seamlessly css source in development environnement.
- Regex filter: Configurable, you can apply cssy's transform selectively
- Plugin: Use cssy as a plugin at application level to configure cssy finely
- Remedy: Enable cssy remedy to handle package that does not export css as commonjs module
Want a nice cocktail recipe ? Use source map in combination with cssy's live source reload feature and chrome's in-browser edition.
Installation
npm install --save cssy
Then add cssy transform to your package.json
. Encapsulate your css processing logic inside your package: use browserify.transform field.
{
// ...
"browserify": { "transform": [ "cssy" ] ] }
}
Options
In you package.json
you can add some options for the current package ([ "cssy", { /* options */ } ]
)
parser
{Array|String}: One or many path to module that export a parserprocessor
{Array|String}: One or many path to module that export a Css processorimport
{Boolean}: Allow @import behavior (default: true)match
{String|Array}: Filter which file cssy must handle. See Regex filter
Path inside parser
and processor
options are either relative to package.json or npm package.
Example:
// ...
"browserify": { "transform": [
[ "cssy",
{
"parser" : [
"./mySassParser",
"./myLessParser"
],
"processor": "./support/myCssProcessor",
"import" : false,
"match" : ["\\.(css|mycss)$",i]
}
]
]}
Notice: Starting from v2, cssy will probably works for with node.js v0.12 (and even v0.10) until the next major version, but is only tested against node.js >= v4
Global configuration
At application level you can change some global cssy behaviors
var cssy = require('cssy')
cssy.config({
// Enable css minification (default: false)
minify: false, // boolean or object: a cssnano options (default is {safe: true})
// Enable source map in the generated source (default: true)
sourcemap: true
})
Css minification is done with cssnano which do a lot of other optimizations. Feel free to use another one inside a global post-processor.
Internal workflow
- Parser Cssy try each parser to transform any kind of source to css (from stylus, less, sass, etc.) with a source map.
- Global pre-processor: Cssy call each Global pre-processor
- processor: Cssy call each local processor
- Global post-processor: Cssy call each Global post-processor
- @import: If enable cssy extract
@import
at-rules (see Import css) - minify: If enable cssy minify css source
- source map: If enable cssy add the source-map
- live reload: If enable cssy add live source reload client to the generated bundle
Context object
Each function that transform a css source (parser, global pre/post processor, processor), receive a context object:
src
{String}: Css sourcefilename
{String}: Css source filepath (relative toprocess.cwd()
)config
{Object}: The cssy's transform configurationmap
{Object}: The css source map (undefined for the parsers: as they must provide it)
Functions
Each function used in cssy (parser, global pre/post processor, processor) use the same API and may be asynchronous or synchronous.
// Asynchronous parser, processor, pre/post processor:
module.exports = function (ctx, done) {
// ... change the ctx object ...
// Return ctx
done(null, ctx)
// Or if something wrong happened
done(new Error('oups...'))
}
// Synchronous parser, processor, pre/post processor:
module.exports = function (ctx) {
// ... change the ctx object ...
return ctx;
}
Css meta-language: sass, stylus, less, ...
Cssy provide parsers for common css meta-languages. But, cssy does not depend on them so you can install only what you use, and control version according to you needs. For instance, to use less sources with cssy, add less to your package dependencies (npm install --save less
).
If you need something more specific, you may add your own parser.
Parser
Parser's job is to read a source from any format (sass, stylus, less, whatever), and to return a css source and a source-map.
- Parsers use the same api than any other function used in cssy
- See options.parser to add your own parser before cssy's parsers
- See cssy's parsers for common css meta-languages as example.
- Parser are executed in series, until one return a context with a source-map.
Processor
For cssy, a processor is an function that transform a cssy context object to another cssy context object. Like for browserify's transform cssy processor are applied only on the sources of the current package. (See too [Global pre/post processor](#Global pre/post processor))
- Parsers use the same api than any other function used in cssy
- See options.processor to add one or many processor
Processor example
Here with postcss but you can use any other library (Preferably with good source-map support)
var autoprefixer = require('autoprefixer');
var postcssCalc = require('postcss-calc');
var customProperties = require("postcss-custom-properties")
var postcss = require('postcss');
module.exports = function(ctx, done) {
var result = postcss()
.use(customProperties())
.use(postcssCalc())
.use(autoprefixer.postcss)
.process(ctx.src, {
map : { prev : ctx.map } // Preserve source map !
});
ctx.src = result.css;
ctx.map = result.map.toJSON();
done(null, ctx)
}
Note: As autoprefixer is very useful, so cssy bundle a processor for it (cssy/autoprefixer
).
You still have to declare it using browserify transform options:
Api:
b.transform('cssy', {'processor': ['cssy/autoprefixer']})
Or in your package.json:
{
// ...
"browserify": {
"transform": [
["cssy", { "processor": ["cssy/autoprefixer"] }]
]
}
// ...
}
Global pre/post processor
Global pre/post processor must be used only at application level (where you bundle your application) for things like global url()
rebasing, optimizations for production, etc. Pre/post processor share the same api than cssy processor.
var cssy = require('cssy')
// Add one or many pre-processors
cssy.pre(function(ctx, done) {
// ... Applied on every source handled by cssy
})
// Add one or many post-processors
cssy.post(function(ctx, done) {
// ... Applied on every source handled by cssy
})
See too use cssy plugin to add pre/post processor
Live source reload
Cssy provide a tiny live source reload mechanism based on websocket for development purpose only.
Classic live source reload for css usually require that all (builded) css source are accessible via an url. This is not convenient with bundled css sources that comes from anywhere in the dependency tree. And this is almost impraticable if css sources are injected somewhere else than the main document (shadow root for instance) without reloading all the page.
Just attach cssy to the http(s) server that serve the application, cssy will do the rest: (browserify bundler must in the same process):
var http = require('http')
var cssy = require('cssy')
var server = http.createServer(/* your application */).listen(8080);
cssy.live(server);
Use your own file watcher
To trigger a change on a css source, just call the change listener returned by cssy.attachServer()
:
var cssyChangeListener = cssy.attachServer(server);
cssyChangeListener('path/to/source.css');
Here is an example with chockidar :
require('chokidar')
.watch('.', {ignored: /[\/\\]\./})
.on('change', cssy.attachServer(server))
Import css
Unless you set the import option to false, @import
at-rules works like a require()
.
For instance with two css file, app.css
and print.css
:
/* app.css */
@import "print.css" print;
body { /* ... */ }
/* print.css */
.not-printable { display: none }
When you inject app.css
, print.css
will be injected too with the media query print
Regex filter
Default filter is all css files and most meta-css-language files: /\.(css|sass|scss|less|styl)$/i
. You can set the match option to filter which file cssy must handle.
match
option is either a String or an Array used to instantiate a new regular expression:
- With a string
"\\.myCss$"
become/\.myCss$/
- With an array, to add regular expression flags
["\\.myCss$","i"]
become/\.myCss$/i
{
// ... package.json ...
"browserify": {
"transform": [
// Match all *.mycss files in src/css
[ "cssy", { match: ["src\\/css\\/.*\\.mycss$","i"] } ]
]
}
}
Cssy plugin
Cssy can be used as a browserify plugin to set global behaviors:
Using browserify api
var browserify = require('browserify');
var cssy = require('cssy');
var b = browserify('./app.css')
b.plugin(cssy, {
// Global configuration:
minify: true, // boolean or object: a cssnano options (default is {safe: true})
sourcemap: false,
// See live source reload:
live: myHttpServerInstance,
// See pre/post processor (function or path to a processor module):
pre: [
'./myPreprocessor',
function anotherPreprocessor(ctx) { return ctx }
],
post: 'post-processor',
// See remedy:
// - Use current package cssy config:
remedy: true,
// - Use set remedy config:
remedy: {
processor: './processor' // (function or path to a processor module)
match: /css$/i,
import: false
}
})
Using browserify command
Browserify use subarg syntaxe. See too browserify plugin
browserify ./app.css -p [ \
cssy \
--minify \
--no-sourcemap # sourcemap = false \
--live './server.js' \
--pre './myPreprocessor' \
--pre 'another-preprocessor' # repeat for an array \
--post 'post-processor' \
--remedy # enable remedy ... \
--remedy [ # ... or use subarg \
--processor './processor' \
--no-import \
--match 'css$' --match 'i' \
] \
]
Remedy
Cssy's remedy is a solution to use libraries that does not export their css sources as commonjs modules
Browserify transforms are scoped to the current package, not its dependency: and that's a good thing !
From module-deps readme: (...) the transformations you specify will not be run for any files in node_modules/. This is because modules you include should be self-contained and not need to worry about guarding themselves against transformations that may happen upstream.
However, if you want to use some parts of a library like semantic-ui, cssy provide a solution at application level (where you bundle your application): the remedy global transform.
Enable remedy:
If remedy options is true
cssy will use the cssy configuration from the package.json
closest to the current working directory :
// Add remedy to a browserify instance (bundler)
bundler.plugin(cssy, { remedy: true })
But you can set specific options has described in the cssy plugin section
// Add remedy to a browserify instance (bundler)
bundler.plugin(cssy, { remedy: { processor: 'myprocessor' } })
Remedy options:
Remedy options are the same of the cssy's transform options.
Symptoms indicating a need for a remedy
Usually, when browserify encounter a source he can't handle correctly (such css) you see something like SyntaxError: Unexpected token ILLEGAL
CssyBrowser API
CssyBrowser()
CssyBrowser is the object exported by a module handled by cssy:
var myCss = require('./my.css');
// myCss is a CssyBrowser
A CssyBrowser instance can be used as:
- An string when used in a context that imply a string: thanks to
CssyBrowser.toString()
that return the css source. - A function, alias of CssyBrowser.insert([to, [media]]), to inject
the css source in the document:
myCss()
,myCss(element)
ormyCss(element, 'media query')
. - An object with the methods described below.
return {Object
}
See CssyBrowser.insert()
CssyBrowser.insert([to], [media])
Insert css source in the DOM
Create and append a <style>
element in the dom at to
. If the source contain
@import
at-rules, imported CssyBrowser modules are injected too.
The content of all the injected <style>
element is binded to css source
change: When .update()
is called by you or by the cssy's live source
reload server.
If a style element with the same parent (to
) and the same media query
already exists, then this function only increment a counter for this kind
of pair (parent/media-query). And remove() calls only decrement this
counter until no more consumer require this style to be inserted.
Parameters:
[to] {
HTMLElement
|ShadowRoot
} Where to inject the style. Default to document's head.[media] {
String
} Set the media attribute of the injected style tag
return {Object
}
An object with:
element
{HTMLElement}: Thestyle
element insertedchildren
{Array}: The other CssyBrowser instances imported and injected by this instanceremove
{Function}: Remove injectedstyle
element and all other CssyBrowser instances imported other CssyBrowser instances imported
CssyBrowser.update(src)
Update current css source
Each inject style element are updated too
Parameters:
- src {
String
}
CssyBrowser.onChange(listener)
Listen for css source changes
Parameters:
- listener {
Function
} Change listener. Receive new css source Change listener. Receive new css source
CssyBrowser.offChange(listener)
Detach change listener
Parameters:
- listener {
Function
}
CssyBrowser.getImports()
Get the imported CssyBrowser instance (based on
@import
at-rules)
return {Array
}
Array of CssyBrowser instance
CssyBrowser.toString()
Override default toString()
return {String
}
The current css source
License: MIT