--- /dev/null
+# PostCSS API
+
+* [`postcss` function](#postcss-function)
+* [`Processor` class](#processor-class)
+* [`LazyResult` class](#lazyresult-class)
+* [`Result` class](#result-class)
+* [`Warning` class](#warning-class)
+* [`CssSyntaxError` class](#csssyntaxerror-class)
+* [Vendor module](#vendor-module)
+* [List module](#list-module)
+* [`Input` class](#input-class)
+* [Nodes common methods](#nodes-common-methods)
+* [Containers common methods](#containers-common-methods)
+* [`Root` node](#root-node)
+* [`AtRule` node](#atrule-node)
+* [`Rule` node](#rule-node)
+* [`Declaration` node](#declaration-node)
+* [`Comment` node](#comment-node)
+
+## `postcss` function
+
+The `postcss` function is the main entry point for PostCSS.
+
+```js
+var postcss = require('postcss');
+```
+
+For those using [TypeScript], typings are already provided in this package.
+Simply, import PostCSS as you would normally.
+
+```ts
+import * as postcss from 'postcss';
+```
+
+[TypeScript]: http://www.typescriptlang.org/
+
+### `postcss(plugins)`
+
+Returns a new [`Processor`] instance that will apply `plugins`
+as CSS processors.
+
+```js
+postcss([autoprefixer, cssnext, cssgrace]).process(css).css;
+```
+
+Arguments:
+
+* `plugins (array)`: list of PostCSS plugins to be included as processors.
+
+Plugins can also be included with the [`Processor#use`] method.
+See its description below for details about plugin formats.
+
+### `postcss.parse(css, opts)`
+
+Parses source `css` and returns a new `Root` node, which contains
+the source CSS nodes.
+
+```js
+// Simple CSS concatenation with source map support
+var root1 = postcss.parse(css1, { from: file1 });
+var root2 = postcss.parse(css2, { from: file2 });
+root1.append(root2).toResult().css;
+```
+
+Arguments:
+
+* `css (string|#toString)`: String with input CSS or any object
+ with `toString()` method, like a Buffer.
+* `opts (object) optional`: options:
+ * `from`: the path to the source CSS file. You should always set `from`,
+ because it is used in map generation and in syntax error messages.
+ * `map`: an object of [source map options].
+ Only `map.prev` is used in `parse`.
+
+### `postcss.plugin(name, initializer)`
+
+Creates a PostCSS plugin with a standard API.
+
+```js
+var remove = postcss.plugin('postcss-remove', function (opts) {
+ opts = opts || {};
+ var filter = opts.prop || 'z-index';
+ return function (css, result) {
+ css.walkDecls(filter, function (decl) {
+ decl.remove();
+ });
+ };
+});
+
+postcss([ remove ]) // with default options
+postcss([ remove({ prop: 'color' })]) // with options
+```
+
+Arguments:
+
+* `name (string)`: PostCSS plugin name. Same as in `name` property
+ in `package.json`. It will be saved in `plugin.postcssPlugin` property.
+* `initializer (function)`: will receive plugin options and should return
+ functions to modify nodes in input CSS.
+
+The newly-wrapped function will provide both the name and PostCSS
+version of the plugin:
+
+```js
+var processor = postcss([replace]);
+processor.plugins[0].postcssPlugin //=> 'postcss-replace'
+processor.plugins[0].postcssVersion //=> '4.1.0'
+```
+
+The plugin function receives 2 arguments: [`Root` node] and [`Result`] instance.
+The function should mutate the provided `Root` node. Alternatively, you can
+create a new `Root` node and override the `result.root` property.
+
+```js
+var cleaner = postcss.plugin('postcss-cleaner', function () {
+ return function (css, result) {
+ result.root = postcss.root();
+ };
+});
+```
+
+As a convenience, plugins also expose a `process` method so that you can use
+them as standalone tools.
+
+```js
+cleaner.process(css, options);
+// This is equivalent to:
+postcss([ cleaner(options) ]).process(css);
+```
+
+Asynchronous plugins should return a `Promise` instance.
+
+```js
+postcss.plugin('postcss-import', function () {
+ return function (css, result) {
+ return new Promise(function (resolve, reject) {
+ fs.readFile('base.css', function (base) {
+ css.prepend(base);
+ resolve();
+ });
+ });
+ };
+});
+```
+
+Add warnings using the [`Node#warn()`] method.
+
+```js
+postcss.plugin('postcss-caniuse-test', function () {
+ return function (css, result) {
+ css.walkDecls(function (decl) {
+ if ( !caniuse.support(decl.prop) ) {
+ decl.warn(result,
+ 'Some browsers do not support ' + decl.prop);
+ }
+ });
+ };
+});
+```
+
+Send data to other plugins using the [`Result#messages`] array.
+
+### `postcss.root(props)`
+
+Creates a new [`Root` node].
+
+```js
+postcss.root({ after: '\n' }).toString() //=> "\n"
+```
+
+Arguments:
+
+* `props (object) optional`: properties for the new root node.
+
+### `postcss.atRule(props)`
+
+Creates a new [`AtRule` node].
+
+```js
+postcss.atRule({ name: 'charset' }).toString() //=> "@charset"
+```
+
+Arguments:
+
+* `props (object) optional`: properties for the new at-rule node.
+
+### `postcss.rule(props)`
+
+Creates a new [`Rule` node].
+
+```js
+postcss.rule({ selector: 'a' }).toString() //=> "a {\n}"
+```
+
+Arguments:
+
+* `props (object) optional`: properties for the new rule node.
+
+### `postcss.decl(props)`
+
+Creates a new [`Declaration` node].
+
+```js
+postcss.decl({ prop: 'color', value: 'black' }).toString() //=> "color: black"
+```
+
+Arguments:
+
+* `props (object) optional`: properties for the new declaration node.
+
+### `postcss.comment(props)`
+
+Creates a new [`Comment` node].
+
+```js
+postcss.comment({ text: 'test' }).toString() //=> "/* test */"
+```
+
+Arguments:
+
+* `props (object) optional`: properties for the new comment node.
+
+### `postcss.vendor`
+
+Contains the [Vendor module](#vendor-module).
+
+```js
+postcss.vendor.unprefixed('-moz-tab') //=> ['tab']
+```
+
+### `postcss.list`
+
+Contains the [List module](#list-module).
+
+```js
+postcss.list.space('5px calc(10% + 5px)') //=> ['5px', 'calc(10% + 5px)']
+```
+
+### `postcss.stringify(node, builder)`
+
+Default function to convert a node tree into a CSS string.
+
+## `Processor` class
+
+A `Processor` instance contains plugins to process CSS. Create
+one `Processor` instance, initialize its plugins, and then use that instance
+on numerous CSS files.
+
+```js
+var processor = postcss([autoprefixer, cssnext, cssgrace]);
+processor.process(css1).css;
+processor.process(css2).css;
+```
+
+### `processor.use(plugin)`
+
+Adds a plugin to be used as a CSS processor.
+
+```js
+var processor = postcss();
+processor.use(autoprefixer()).use(cssnext()).use(cssgrace());
+```
+
+Arguments:
+
+* `plugin (function|#postcss|Processor)`: PostCSS plugin. It can be in three
+ formats:
+ * A plugin created by [`postcss.plugin()`] method.
+ * A function. PostCSS will pass the function a [`Root` node]
+ as the first argument and current [`Result`] instance as the second.
+ * An object with a `postcss` method. PostCSS will use that method
+ as described in #2.
+ * Another `Processor` instance. PostCSS will copy plugins
+ from that instance into this one.
+
+Plugins can also be added by passing them as arguments when creating
+a `postcss` instance (see [`postcss(plugins)`]).
+
+Asynchronous Plugins should return a `Promise` instance.
+
+### `processor.process(css, opts)`
+
+Parses source CSS and returns a [`LazyResult`] instance. Because some plugins
+can be asynchronous it doesn’t make any transformations. Transformations will
+be applied in the `LazyResult`’s methods.
+
+```js
+processor.process(css, { from: 'a.css', to: 'a.out.css' }).then(function (result) {
+ console.log(result.css);
+});
+```
+
+Arguments:
+
+* `css (string|#toString|Result)`: String with input CSS or any object
+ with a `toString()` method, like a Buffer. Optionally, send a [`Result`]
+ instance and the processor will take the existing [`Root`] parser from it.
+* `opts (object) optional`: options:
+ * `from`: the path of the CSS source file. You should always set `from`,
+ because it is used in source map generation and syntax error messages.
+ * `to`: the path where you’ll put the output CSS file. You should always set
+ `to` to generate correct source maps.
+ * `parser`: function to generate AST by string.
+ * `stringifier`: class to generate string by AST.
+ * `syntax`: object with `parse` and `stringify` functions.
+ * `map`: an object of [source map options].
+
+### `processor.plugins`
+
+Contains plugins added to this processor.
+
+```js
+var processor = postcss([cssnext, cssgrace]);
+processor.plugins.length //=> 2
+```
+
+### `processor.version`
+
+Contains the current version of PostCSS.
+
+```js
+postcss().version //=> '4.0.5'
+```
+
+## `LazyResult` class
+
+A promise proxy for the result of PostCSS transformations.
+
+A `LazyResult` instance is returned by [`Processor#process(css, opts)`].
+
+```js
+var lazy = postcss([cssnext]).process(css);
+```
+
+### `lazy.then(onFulfilled, onRejected)`
+
+Processes input CSS through synchronous and asynchronous plugins
+and calls `onFulfilled` with a [`Result`] instance. If a plugin throws
+an error, the `onRejected` callback will be executed.
+
+```js
+postcss([cssnext]).process(css).then(function(result) {
+ console.log(result.css);
+});
+```
+
+This method is a standard [Promise] method.
+
+### `lazy.catch(onRejected)`
+
+Processes input CSS through synchronous and asynchronous plugins
+and calls `onRejected` for each error thrown in any plugin.
+
+```js
+postcss([cssnext]).process(css).then(function(result) {
+ console.log(result.css);
+}).catch(function (error) {
+ console.error(error);
+});
+```
+
+This method is a standard [Promise] method.
+
+### `lazy.toString()`
+
+Alias for the `LazyResult#css` property.
+
+### `lazy.css`
+
+Processes input CSS through synchronous plugins, converts `Root` to a CSS
+string and returns [`Result#css`].
+
+```js
+processor.process(css).css;
+```
+
+This property will only work with synchronous plugins. If the processor
+contains any asynchronous plugins it will throw an error. In this case,
+you should use [`LazyResult#then()`] instead.
+
+```js
+postcss([cssnext]).then(function (result) {
+ console.log(result.css);
+});
+```
+
+### `lazy.content`
+
+An alias for the `css` property. Use it with syntaxes that generate non-CSS
+output.
+
+```js
+lazy.css === lazy.content;
+```
+
+### `lazy.map`
+
+Processes input CSS through synchronous plugins and returns [`Result#map`].
+
+```js
+if ( result.map ) {
+ fs.writeFileSync(result.opts.to + '.map', result.map.toString());
+}
+```
+
+This property will only work with synchronous plugins. If the processor
+contains any asynchronous plugins it will throw an error. In this case,
+you should use [`LazyResult#then()`] instead.
+
+```js
+postcss([cssnext]).then(function (result) {
+ if ( result.map ) {
+ fs.writeFileSync(result.opts.to + '.map', result.map.toString());
+ }
+});
+```
+
+### `lazy.root`
+
+Processes input CSS through synchronous plugins and returns
+[`Result#root`](#resultroot).
+
+This property will only work with synchronous plugins. If the processor
+contains any asynchronous plugins it will throw an error. In this case,
+you should use [`LazyResult#then()`] instead.
+
+```js
+postcss([cssnext]).then(function (result) {
+ console.log(result.root);
+});
+```
+
+### `lazy.warnings()`
+
+Processes input CSS through synchronous plugins and calls [`Result#warnings()`].
+
+```js
+postcss([cssnext]).warnings().forEach(function (message) {
+ console.warn(message.text);
+});
+```
+
+This property will only work with synchronous plugins. If the processor
+contains any asynchronous plugins it will throw an error. In this case,
+you should use [`LazyResult#then()`] instead.
+
+```js
+postcss([cssnext]).then(function (result) {
+ result.warnings().forEach(function (message) {
+ console.warn(message.text);
+ });
+});
+```
+
+### `lazy.messages`
+
+Processes input CSS through synchronous plugins and returns [`Result#messages`].
+
+This property will only work with synchronous plugins. If the processor
+contains any asynchronous plugins it will throw an error. In this case,
+you should use [`LazyResult#then()`] instead.
+
+### `lazy.processor`
+
+Returns a [`Processor`] instance, which will be used for CSS transformations.
+
+```js
+var lazy = postcss([cssnext, cssgrace]).process(css);
+lazy.processor.plugins.length //=> 2
+```
+
+### `lazy.opts`
+
+Options from the [`Processor#process(css, opts)`] call that produced
+this `Result` instance.
+
+```js
+postcss().process(css, opts).opts == opts;
+```
+
+## `Result` class
+
+Provides the result of the PostCSS transformations.
+
+A `Result` instance is returned by [`Root#toResult(opts)`]
+or [`LazyResult#then()`] methods.
+
+```js
+postcss([cssnext]).process(css).then(function (result1) {
+ console.log(result1.css);
+});
+var result2 = postcss.parse(css).toResult();
+```
+
+### `result.toString()`
+
+Alias for [`Result#css`] property.
+
+### `result.warn(text, opts)`
+
+Creates an instance of [`Warning`] and adds it to [`Result#messages`].
+
+```js
+var plugin = postcss.plugin('postcss-important', function () {
+ return function (css, result) {
+ css.walkDecls(function (decl) {
+ if ( decl.important ) {
+ result.warn('Try to avoid !important', { node: decl });
+ }
+ });
+ };
+});
+
+postcss([plugin]).process(css).then(function (result) {
+ result.warnings() //=> [{
+ // plugin: 'postcss-important-warning',
+ // text: 'Try to avoid !important'
+ // node: { type: 'decl', … }
+ // }]
+});
+```
+
+Arguments:
+
+* `text (string)`: warning message. It will be used in the `text` property of
+ the message object.
+* `opts (object) optional`: properties to assign to the message object.
+ * `node`: CSS node that was the source of the warning.
+ * `word (string)`: word inside a node’s string that should be highlighted
+ as the source of the warning.
+ * `index` (number): index inside a node’s string that should be highlighted
+ as the source of the warning.
+ * `plugin`: name of the plugin that created this warning. `Result#warn()` will
+ automatically fill it with the `plugin.postcssPlugin` value.
+
+### `result.warnings()`
+
+Returns warnings from plugins. Filters [`Warning`] instances
+from [Result#messages].
+
+```js
+result.warnings().forEach(function (message) {
+ console.log(message.toString());
+});
+```
+
+### `result.css`
+
+A CSS string representing this `Result`’s '`Root` instance.
+
+```js
+postcss.parse('a{}').toResult().css //=> "a{}"
+```
+
+### `result.content`
+
+An alias for the `css` property. Use it with syntaxes that generate non-CSS
+output.
+
+```js
+result.css === result.content;
+```
+
+### `result.map`
+
+An instance of the `SourceMapGenerator` class from the [`source-map`] library,
+representing changes to the `Result`’s `Root` instance.
+
+```js
+result.map.toJSON() //=> { version: 3, file: 'a.css', sources: ['a.css'], … }
+```
+
+This property will have a value *only if the user does not want an inline source
+map*. By default, PostCSS generates inline source maps, written directly into
+the processed CSS. The `map` property will be empty by default.
+
+An external source map will be generated — and assigned to `map` —
+only if the user has set the `map.inline` option to `false`, or if PostCSS
+was passed an external input source map.
+
+```js
+if ( result.map ) {
+ fs.writeFileSync(result.opts.to + '.map', result.map.toString());
+}
+```
+
+### `result.root`
+
+Contains the [`Root` node] after all transformations.
+
+```js
+root.toResult().root == root;
+```
+
+### `result.messages`
+
+Contains messages from plugins (e.g., warnings or custom messages).
+
+Each message should have `type` and `plugin` properties.
+
+```js
+postcss.plugin('postcss-min-browser', function () {
+ return function (css, result) {
+ var browsers = detectMinBrowsersByCanIUse(css);
+ result.messages.push({
+ type: 'min-browser',
+ plugin: 'postcss-min-browser',
+ browsers: browsers
+ });
+ };
+});
+```
+
+Add a warning using [`Result#warn()`] and get all warnings
+using the [`Result#warnings()`](#resultwarnings) method.
+
+### `result.processor`
+
+Returns the [`Processor`] instance used for this transformation.
+
+```js
+result.processor.plugins.forEach(function (plugin) {
+ if ( plugin.postcssPlugin == 'postcss-bad' ) {
+ throw 'postcss-good is incompatible with postcss-bad';
+ }
+});
+```
+
+### `result.opts`
+
+Options from the [`Processor#process(css, opts)`] or [`Root#toResult(opts)`]
+call that produced this `Result` instance.
+
+```js
+root.toResult(opts).opts == opts;
+```
+
+## `Warning` class
+
+Represents a plugin warning. It can be created using [`Node#warn()`].
+
+```js
+if ( decl.important ) {
+ decl.warn(result, 'Try to avoid !important');
+}
+```
+
+### `warning.toString()`
+
+Returns a string with the error position and message.
+
+```js
+warning.toString() //=> 'postcss-important:a.css:10:4: Try to avoid !important'
+```
+
+### `warning.text`
+
+Contains the warning message.
+
+```js
+warning.text //=> 'Try to avoid !important'
+```
+
+### `warning.plugin`
+
+Contains the name of the plugin that created this warning. When you call
+[`Node#warn()`] it will fill this property automatically.
+
+```js
+warning.plugin //=> 'postcss-important'
+```
+
+### `warning.node`
+
+Contains the CSS node that caused the warning.
+
+```js
+warning.node.toString() //=> 'color: white !important'
+```
+
+### `warning.line`
+
+The line in the input file with this warning’s source.
+
+```js
+warning.line //=> 5
+```
+
+### `warning.column`
+
+Column in the input file with this warning’s source.
+
+```js
+warning.column //=> 4
+```
+
+## `CssSyntaxError` class
+
+The CSS parser throws this error for broken CSS.
+
+```js
+postcss.parse('a{') //=> CssSyntaxError
+```
+
+Custom parsers can throw this error for broken custom syntax
+using the [`Node#error()`](#nodeerrormessage) method.
+
+```js
+throw node.error('Unknown variable', { plugin: 'postcss-vars' });
+```
+
+### `error.toString()`
+
+Returns a string with the error position, message and source code of the
+broken part.
+
+```js
+error.toString() //=> CssSyntaxError: app.css:1:1: Unclosed block
+ // a {
+ // ^
+```
+
+### `error.showSourceCode(color)`
+
+Returns a few lines of CSS source that caused the error.
+
+```js
+error.showSourceCode() //=>
+ // a {
+ // bad
+ // ^
+ // }
+```
+
+Arguments:
+
+* `color (boolean) optional`: whether arrow will be colored red by terminal
+ color codes. By default, PostCSS will use `process.stdout.isTTY` and
+ `process.env.NODE_DISABLE_COLORS`.
+
+If the CSS has an input source map without `sourceContent`, this method will
+return an empty string.
+
+### `error.message`
+
+Contains full error text in the GNU error format.
+
+```js
+error.message //=> 'a.css:1:1: Unclosed block'
+```
+
+### `error.reason`
+
+Contains only the error description.
+
+```js
+error.reason //=> 'Unclosed block'
+```
+
+### `error.plugin`
+
+Contains the PostCSS plugin name if the error didn’t come from the CSS parser.
+
+```js
+error.plugin //=> 'postcss-vars'
+```
+
+PostCSS will fill it automatically.
+
+### `error.file`
+
+Contains the absolute path to the broken file. If you use it, send the `from`
+option to the parser.
+
+```js
+error.file //=> 'a.sass'
+```
+
+PostCSS will use the input source map to detect the original error location.
+If you wrote a Sass file, compiled it to CSS and then parsed it with PostCSS,
+PostCSS will show the original position in the Sass file.
+
+If you need the position in the PostCSS input (e.g., to debug the previous
+compiler), use `error.input.file`.
+
+```js
+error.file //=> 'a.sass'
+error.input.file //=> 'a.css'
+```
+
+### `error.line`
+
+Contains the source line of the error.
+
+```js
+error.line //=> 2
+```
+
+PostCSS will use the input source map to detect the original error location.
+If you wrote a Sass file, compiled it to CSS and then parsed it with PostCSS,
+PostCSS will show the original position in the Sass file.
+
+If you need the position in the PostCSS input (e.g., to debug the previous
+compiler), use `error.input.file`.
+
+```js
+error.line //=> 2
+error.input.line //=> 4
+```
+
+### `error.column`
+
+Contains the source column of the error.
+
+```js
+error.column //=> 1
+```
+
+PostCSS will use the input source map to detect the original error location.
+If you wrote a Sass file, compiled it to CSS and then parsed it with PostCSS,
+PostCSS will show the original position in the Sass file.
+
+If you need the position in the PostCSS input (e.g., to debug the previous
+compiler), use `error.input.file`.
+
+```js
+error.column //=> 1
+error.input.column //=> 4
+```
+
+### `error.source`
+
+Contains the source code of the broken file.
+
+```js
+error.source //=> 'a {} b {'
+```
+
+PostCSS will use the input source map to detect the original error location.
+If you wrote a Sass file, compiled it to CSS and then parsed it with PostCSS,
+PostCSS will show the original position in the Sass file.
+
+If you need the position in the PostCSS input (e.g., to debug the previous
+compiler), use `error.input.file`.
+
+```js
+error.source //=> 'a { b {} }'
+error.input.column //=> 'a b { }'
+```
+
+## Vendor module
+
+Contains helpers for working with vendor prefixes.
+
+```js
+var vendor = postcss.vendor;
+```
+
+### `vendor.prefix(string)`
+
+Returns the vendor prefix extracted from an input string.
+
+```js
+postcss.vendor.prefix('-moz-tab-size') //=> '-moz-'
+```
+
+### `vendor.unprefixed(string)`
+
+Returns the input string stripped of its vendor prefix.
+
+```js
+postcss.vendor.unprefixed('-moz-tab-size') //=> 'tab-size'
+```
+
+## List module
+
+Contains helpers for safely splitting lists of CSS values,
+preserving parentheses and quotes.
+
+```js
+var list = postcss.list;
+```
+
+### `list.space(string)`
+
+Safely splits space-separated values (such as those for `background`,
+`border-radius`, and other shorthand properties).
+
+```js
+postcss.list.space('1px calc(10% + 1px)') //=> ['1px', 'calc(10% + 1px)']
+```
+
+### `list.comma(string)`
+
+Safely splits comma-separated values (such as those
+for `transition-*` and `background` properties).
+
+```js
+postcss.list.comma('black, linear-gradient(white, black)')
+//=> ['black', 'linear-gradient(white, black)']
+```
+
+## `Input` class
+
+Represents the source CSS.
+
+```js
+var root = postcss.parse(css, { from: file });
+var input = root.source.input;
+```
+
+### `input.file`
+
+The absolute path to the CSS source file defined with the [`from` option].
+
+```js
+var root = postcss.parse(css, { from: 'a.css' });
+root.source.input.file //=> '/home/ai/a.css'
+```
+
+### `input.id`
+
+The unique ID of the CSS source. Used if `from`
+option is not provided (because PostCSS does not know the file path).
+
+```js
+var root = postcss.parse(css);
+root.source.input.file //=> undefined
+root.source.input.id //=> <input css 1>
+```
+
+### `input.from`
+
+The CSS source identifier. Contains [`input.file`](#inputfile) if the user set
+the [`from` option], or [`input.id`](#inputid) if they did not.
+
+```js
+var root = postcss.parse(css, { from: 'a.css' });
+root.source.input.from //=> '/home/ai/a.css'
+
+var root = postcss.parse(css);
+root.source.input.from //=> <input css 1>
+```
+
+### `input.map`
+
+Represents the input source map passed from a compilation step before PostCSS
+(e.g., from the Sass compiler).
+
+`map.consumer()` returns an instance of the `SourceMapConsumer` class
+from the [`source-map`] library.
+
+```js
+root.source.input.map.consumer().sources //=> ['a.sass']
+```
+
+### `input.origin(line, column)`
+
+Reads the input source map and returns a symbol position in the input source
+(e.g., in a Sass file that was compiled to CSS before being passed
+to PostCSS):
+
+```js
+root.source.input.origin(1, 1) //=> { file: 'a.css', line: 3, column: 1 }
+```
+
+## Nodes: common methods
+
+All node classes inherit the following common methods.
+
+### `node.type`
+
+Returns a string representing the node’s type.
+
+Possible values are `root`, `atrule`, `rule`, `decl`, or `comment`.
+
+```js
+postcss.decl({ prop: 'color', value: 'black' }).type //=> 'decl'
+```
+
+### `node.parent`
+
+Returns the node’s parent node.
+
+```js
+root.nodes[0].parent == root;
+```
+
+### `node.source`
+
+Returns the input source of the node, with the following properties:
+
+- `node.source.input`: An [`Input`] instance.
+- `node.source.start`: The starting position of the node’s source —
+ line and column.
+- `node.source.end`: The ending position of the node’s source — line and column.
+
+```js
+decl.source.input.from //=> '/home/ai/a.sass'
+decl.source.start //=> { line: 10, column: 2 }
+decl.source.end //=> { line: 10, column: 12 }
+```
+
+The property is used in source map generation.
+
+If you create a node manually (e.g., with `postcss.decl()`),
+that node will not have a `source` property and will be absent
+from the source map. For this reason, the plugin developer should consider
+cloning nodes to create new ones (in which case the new node’s source
+will reference the original, cloned node) or setting the `source` property
+manually.
+
+```js
+// Bad
+var prefixed = postcss.decl({ prop: '-moz-' + decl.prop, value: decl.value });
+
+// Good
+var prefixed = decl.clone({ prop: '-moz-' + decl.prop });
+```
+
+```js
+if ( atrule.name == 'add-link' ) {
+ var rule = postcss.rule({ selector: 'a' }); // Rule has no source
+ atrule.parent.insertBefore(atrule, rule); // We add it because of atrule
+ rule.source = atrule.source; // So we copy source from atrule
+}
+```
+
+### `node.raws`
+
+Contains information to generate byte-to-byte equal node string
+as it was in the origin input.
+
+Every parser saves its own properties, but the default CSS parser uses:
+
+* `before`: the space symbols before the node. It also stores `*` and `_`
+ symbols before the declaration (IE hack).
+* `after`: the space symbols after the last child of the node to the end of the
+ node.
+* `between`: the symbols between the property and value for declarations,
+ selector and `{` for rules, or last parameter and `{` for at-rules.
+* `semicolon`: contains `true` if the last child has an (optional) semicolon.
+* `afterName`: the space between the at-rule’s name and its parameters.
+* `left`: the space symbols between `/*` and the comment’s text.
+* `right`: the space symbols between the comment’s text and `*/`.
+* `important`: the content of the important statement,
+ if it is not just `!important`.
+
+PostCSS cleans selectors, declaration values and at-rule parameters
+from comments and extra spaces, but it stores origin content
+in `raws` properties. As such, if you don’t change a declaration’s value,
+PostCSS will use the raw value with comments.
+
+### `node.toString()`
+
+Returns a CSS string representing the node.
+
+```js
+postcss.rule({ selector: 'a' }).toString() //=> 'a {}''
+```
+
+Arguments:
+
+* `stringifier (functions|object) optional`: a syntax to use
+ in string generation.
+
+### `node.error(message, opts)`
+
+Returns a [`CssSyntaxError`] instance containing the original position
+of the node in the source, showing line and column numbers and also
+a small excerpt to facilitate debugging.
+
+If present, an input source map will be used to get the original position
+of the source, even from a previous compilation step
+(e.g., from Sass compilation).
+
+This method produces very useful error messages.
+
+```js
+if ( !variables[name] ) {
+ throw decl.error('Unknown variable ' + name, { word: name });
+ // CssSyntaxError: postcss-vars:a.sass:4:3: Unknown variable $black
+ // a
+ // color: $black
+ // ^
+ // background: white
+}
+```
+
+Arguments:
+
+* `message (string)`: error description.
+* `opts (object) optional`: options.
+ * `plugin (string)`: plugin name that created this error.
+ PostCSS will set it automatically.
+ * `word (string)`: a word inside a node’s string that should be highlighted
+ as the source of the error.
+ * `index` (number): an index inside a node’s string that should be highlighted
+ as the source of the error.
+
+### `node.warn(result, text, opts)`
+
+This method is provided as a convenience wrapper for [`Result#warn()`].
+
+```js
+var plugin = postcss.plugin('postcss-deprecated', function () {
+ return function (css, result) {
+ css.walkDecls('bad', function (decl) {
+ decl.warn(result, 'Deprecated property bad');
+ });
+ };
+});
+```
+
+Arguments:
+
+* `result`: The [`Result`] instance that will receive the warning.
+* `text (string)`: warning message. It will be used in the `text` property of
+ the message object.
+* `opts (object) optional`: properties to assign to the message object.
+ * `word (string)`: word inside a node’s string that should be highlighted
+ as the source of the warning.
+ * `index` (number): index inside a node’s string that should be highlighted
+ as the source of the warning.
+ * `plugin`: name of the plugin that created this warning. `Result#warn()` will
+ automatically fill it with the `plugin.postcssPlugin` value.
+
+Note that `opts.node` is automatically passed to [`Result#warn()`] for you.
+
+### `node.next()` and `node.prev()`
+
+Returns the next/previous child of the node’s parent.
+Returns `undefined` if the current node is the last/first child.
+
+```js
+var annotation = decl.prev();
+if ( annotation.type == 'comment' ) {
+ readAnnotation( annotation.text );
+}
+```
+
+### `node.root()`
+
+Returns the `Root` instance of the node’s tree.
+
+```js
+root.nodes[0].nodes[0].root() == root
+```
+
+### `node.remove()`
+
+Removes the node from its parent and cleans the `parent` properties from the
+node and its children.
+
+```js
+if ( decl.prop.match(/^-webkit-/) ) {
+ decl.remove();
+}
+```
+
+### `node.replaceWith(...otherNodes)`
+
+Inserts node(s) before the current node and removes the current node.
+
+```js
+if ( atrule.name == 'mixin' ) {
+ atrule.replaceWith(mixinRules[atrule.params]);
+}
+```
+
+### `node.clone(props)`
+
+Returns a clone of the node.
+
+The resulting cloned node and its (cloned) children will have a clean `parent`
+and code style properties.
+
+```js
+var cloned = decl.clone({ prop: '-moz-' + decl.prop });
+cloned.raws.before //=> undefined
+cloned.parent //=> undefined
+cloned.toString() //=> -moz-transform: scale(0)
+```
+
+Arguments:
+
+* `props (object) optional`: new properties to override in the clone.
+
+### `node.cloneBefore(props)` and `node.cloneAfter(props)`
+
+Shortcut to clone the node and insert the resulting cloned node before/after
+the current node.
+
+```js
+decl.cloneBefore({ prop: '-moz-' + decl.prop });
+```
+
+Arguments:
+
+* `props (object) optional`: new properties to override in the clone.
+
+### `node.moveTo(newParent)`
+
+Removes the node from its current parent and inserts it
+at the end of `newParent`.
+
+This will clean the `before` and `after` code style properties from the node
+and replace them with the indentation style of `newParent`. It will also clean
+the `between` property if `newParent` is in another `Root`.
+
+```js
+atrule.moveTo(atrule.parent.parent);
+```
+
+Arguments:
+
+* `newParent: (Container)`: container node where the current node will be moved.
+
+### `node.moveBefore(otherNode)` and `node.moveAfter(otherNode)`
+
+Removes the node from its current parent and inserts it into a new parent
+before/after `otherNode`.
+
+This will also clean the node’s code style properties just as it would in
+`node.moveTo(newParent)`.
+
+Arguments:
+
+* `otherNode (Node)`: node that will be after/before current node after moving.
+
+### `node.raw(prop, defaultType)`
+
+Returns a code style property value. If the node is missing the code style
+property (because the node was manually built or cloned), PostCSS will try
+to autodetect the code style property by looking at other nodes in the tree.
+
+```js
+var root = postcss.parse('a { background: white }');
+root.nodes[0].append({ prop: 'color', value: 'black' });
+root.nodes[0].nodes[1].raws.before //=> ' '
+```
+
+Arguments:
+
+* `prop (string)`: name or code style property.
+* `defaultType (string)`: name of default value. It can be easily missed
+ if the value is the same as `prop`.
+
+## Containers: common methods
+
+The `Root`, `AtRule`, and `Rule` container nodes inherit some common methods
+to help work with their children.
+
+Note that all containers can store *any* content. If you write a rule inside
+a rule, PostCSS will parse it.
+
+### `container.nodes`
+
+An array containing the container’s children.
+
+```js
+var root = postcss.parse('a { color: black }');
+root.nodes.length //=> 1
+root.nodes[0].selector //=> 'a'
+root.nodes[0].nodes[0].prop //=> 'color'
+```
+
+### `container.first`
+
+The container’s first child.
+
+```js
+rule.first == rules.nodes[0];
+```
+
+### `container.last`
+
+The container’s last child.
+
+```js
+rule.last == rule.nodes[rule.nodes.length - 1];
+```
+
+### `container.index(child)`
+
+Returns a `child`’s index within the container’s `nodes` array.
+
+```js
+rule.index( rule.nodes[2] ) //=> 2
+```
+
+Arguments:
+
+* `child (Node)`: child of the current container.
+
+### `container.every(callback)`
+
+Returns `true` if `callback` returns true for all of the container’s children.
+
+```js
+var noPrefixes = rule.every(function (decl) {
+ return decl.prop[0] != '-';
+});
+```
+
+Arguments:
+
+* `callback (function)`: iterator. Returns true or false.
+
+### `container.some(callback)`
+
+Returns `true` if `callback` returns true for (at least) one
+of the container’s children.
+
+```js
+var hasPrefix = rule.some(function (decl) {
+ return decl.prop[0] == '-';
+});
+```
+
+Arguments:
+
+* `callback (function)`: iterator. Returns true or false.
+
+### `container.each(callback)`
+
+Iterates through the container’s immediate children, calling `callback`
+for each child.
+
+Returning `false` in the `callback` will break iteration.
+
+```js
+var color;
+rule.each(function (decl) {
+ if ( decl.prop == 'color' ) {
+ color = decl.value;
+ return false;
+ }
+});
+```
+
+Arguments:
+
+* `callback (function)`: iterator. Receives each node and its index.
+
+Unlike the `for {}`-cycle or `Array#forEach()` this iterator is safe
+if you are mutating the array of child nodes during iteration.
+PostCSS will adjust the current index to match the mutations.
+
+```js
+var root = postcss.parse('a { color: black; z-index: 1 }');
+var rule = root.first;
+
+for ( var i = 0; i < rule.nodes.length; i++ ) {
+ var decl = rule.nodes[i];
+ decl.cloneBefore({ prop: '-webkit-' + decl.prop });
+ // Cycle will be infinite, because cloneBefore moves the current node
+ // to the next index
+}
+
+rule.each(function (decl) {
+ decl.cloneBefore({ prop: '-webkit-' + decl.prop });
+ // Will be executed only for color and z-index
+});
+```
+
+`container.each()` only iterates through the container’s immediate children.
+If you need to recursively iterate through all the container’s descendant nodes,
+use `container.walk()`.
+
+### `container.walk(callback)`
+
+Traverses the container’s descendant nodes, calling `callback` for each node.
+
+```js
+root.walk(function (node) {
+ // Traverses all descendant nodes.
+});
+```
+
+Arguments:
+
+* `callback (function)`: iterator. Receives each node and its index.
+
+Like `container.each()`, this method is safe to use
+if you are mutating arrays during iteration.
+
+If you only need to iterate through the container’s immediate children,
+use `container.each()`.
+
+### `container.walkDecls([propFilter,] callback)`
+
+Traverses the container’s descendant nodes, calling `callback` for each
+declaration node.
+
+```js
+root.walkDecls(function (decl) {
+ if ( decl.prop.match(/^-webkit-/) ) {
+ decl.remove();
+ }
+});
+```
+
+Arguments:
+
+* `propFilter: (string|RegExp) optional`: string or regular expression
+ to filter declarations by property name.
+ * `callback (function)`: iterator. Receives each declaration node and its
+ index.
+
+If you pass a `propFilter`, iteration will only happen over declarations with
+matching properties.
+
+```js
+// Make a flat design
+root.walkDecls('border-radius', function (decl) {
+ decl.remove();
+});
+root.walkDecls(/^background/, function (decl) {
+ decl.value = takeFirstColorFromGradient(decl.value);
+});
+```
+
+Like `container.each()`, this method is safe to use if you are mutating
+arrays during iteration.
+
+### `container.walkAtRules([nameFilter,] callback)`
+
+Traverses the container’s descendant nodes, calling `callback` for each
+at-rule node.
+
+```js
+root.walkAtRules(function (rule) {
+ if ( rule.name.match(/^-webkit-/) ) rule.remove();
+});
+```
+
+Arguments:
+
+* `nameFilter: (string|RegExp) optional`: string or regular expression to filter
+ at-rules by name.
+ * `callback (function)`: iterator. Receives each at-rule and its index.
+
+If you pass a `filter`, iteration will only happen over at-rules that have
+matching names.
+
+```js
+var first = false;
+root.walkAtRules('charset', function (rule) {
+ if ( !first ) {
+ first = true;
+ } else {
+ rule.remove();
+ }
+});
+```
+
+Like `container.each()`, this method is safe to use if you are mutating arrays
+during iteration.
+
+### `container.walkRules([selectorFilter,] callback)`
+
+Traverses the container’s descendant nodes, calling `callback` for each
+rule node.
+
+```js
+var selectors = [];
+root.walkRules(function (rule) {
+ selectors.push(rule.selector);
+});
+console.log('Your CSS uses ' + selectors.length + ' selectors');
+```
+
+Arguments:
+
+* `selectorFilter: (string|RegExp) optional`: string or regular expression
+ to filter rules by selector.
+* `callback (function)`: iterator. Receives each rule node and its index.
+
+If you pass a `selectorFilter`, iteration will only happen over rules with
+matching selectors.
+
+Like `container.each()`, this method is safe to use if you are mutating arrays
+during iteration.
+
+### `container.walkComments(callback)`
+
+Traverses the container’s descendant nodes, calling `callback` for each
+comment node.
+
+```js
+root.walkComments(function (comment) {
+ comment.remove();
+});
+```
+
+Arguments:
+
+* `callback (function)`: iterator. Receives each comment node and its index.
+
+Like `container.each()`, this method is safe to use if you are mutating arrays
+during iteration.
+
+### `container.replaceValues(pattern, opts, callback)`
+
+Passes all declaration values within the container that match `pattern` through
+`callback`, replacing those values with the returned result of `callback`.
+
+This method is useful if you are using a custom unit or function and need
+to iterate through all values.
+
+```js
+root.replaceValues(/\d+rem/, { fast: 'rem' }, function (string) {
+ return 15 * parseInt(string) + 'px';
+});
+```
+
+Arguments:
+
+* `pattern (string|RegExp)`: replace pattern.
+* `opts (object) optional`: options to speed up the search:
+ * `props`: An array of property names. The method will only search for values
+ that match `regexp` within declarations of listed properties.
+ * `fast`: A string that’s used to narrow down values and speed up
+ the regexp search. Searching every single value with a regexp can be slow.
+ If you pass a `fast` string, PostCSS will first check whether the value
+ contains the `fast` string; and only if it does will PostCSS check that
+ value against `regexp`. For example, instead of just checking for `/\d+rem/`
+ on all values, set `fast: 'rem'` to first check whether a value has
+ the `rem` unit, and only if it does perform the regexp check.
+* `callback (function|string)`: string to replace `pattern` or callback that
+ returns a new value. The callback will receive the same arguments as those
+ passed to a function parameter of [`String#replace`].
+
+[`String#replace`]: (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replace#Specifying_a_function_as_a_parameter)
+
+### `container.prepend(...nodes)` and `container.append(...nodes)`
+
+Inserts new nodes to the start/end of the container.
+
+```js
+var decl = postcss.decl({ prop: 'color', value: 'black' });
+rule.append(decl);
+```
+
+```js
+var decl1 = postcss.decl({ prop: 'color', value: 'black' });
+var decl2 = postcss.decl({ prop: 'background-color', value: 'white' });
+rule.prepend(decl1, decl2);
+```
+
+Arguments:
+
+* `node (Node|array|object|string)`: new node.
+
+Because each node class is identifiable by unique properties, use
+the following shortcuts to create nodes in insert methods:
+
+```js
+root.append({ name: 'charset', params: '"UTF-8"' }); // at-rule
+root.append({ selector: 'a' }); // rule
+rule.append({ prop: 'color', value: 'black' }); // declaration
+rule.append({ text: 'Comment' }) // comment
+```
+
+A string containing the CSS of the new element can also be used.
+This approach is slower than the above shortcuts.
+
+```js
+root.append('a {}');
+root.first.append('color: black; z-index: 1');
+```
+
+### `container.insertBefore(oldNode, newNode)` and `container.insertAfter(oldNode, newNode)`
+
+Insert `newNode` before/after `oldNode` within the container.
+
+```js
+rule.insertBefore(decl, decl.clone({ prop: '-webkit-' + decl.prop }));
+```
+
+Arguments:
+
+* `oldNode (Node|number)`: child or child’s index.
+* `node (Node|array|object|string)`: new node.
+
+### `container.removeChild(node)`
+
+Removes `node` from the container and cleans the `parent` properties from the
+node and its children.
+
+```js
+rule.nodes.length //=> 5
+rule.removeChild(decl);
+rule.nodes.length //=> 4
+decl.parent //=> undefined
+```
+
+Arguments:
+
+* `node (Node|number)`: child or child’s index.
+
+### `container.removeAll()`
+
+Removes all children from the container and cleans their `parent` properties.
+
+```js
+rule.removeAll();
+rule.nodes.length //=> 0
+```
+
+## `Root` node
+
+Represents a CSS file and contains all its parsed nodes.
+
+```js
+var root = postcss.parse('a{color:black} b{z-index:2}');
+root.type //=> 'root'
+root.nodes.length //=> 2
+```
+
+### `root.toResult(opts)`
+
+Returns a [`Result`] instance representing the root’s CSS.
+
+```js
+var root1 = postcss.parse(css1, { from: 'a.css' });
+var root2 = postcss.parse(css2, { from: 'b.css' });
+
+root1.append(root2);
+var result = root1.toResult({ to: 'all.css', map: true });
+```
+
+Arguments:
+
+* `opts (object) optional`: options:
+ * `to`: the path where you’ll put the output CSS file. You should always set
+ `to` to generate correct source maps.
+ * `map`: an object of [source map options].
+
+## `AtRule` node
+
+Represents an at-rule.
+
+If it’s followed in the CSS by a `{}` block, this node will have a `nodes`
+property representing its children.
+
+
+```js
+var root = postcss.parse('@charset "UTF-8"; @media print {}');
+
+var charset = root.first;
+charset.type //=> 'atrule'
+charset.nodes //=> undefined
+
+var media = root.last;
+media.nodes //=> []
+```
+
+### `atrule.name`
+
+The at-rule’s name. This is the identifier that immediately follows the `@`.
+
+```js
+var root = postcss.parse('@media print {}');
+var media = root.first;
+media.name //=> 'media'
+```
+
+### `atrule.params`
+
+The at-rule’s parameters. These are the values that follow the at-rule’s name
+but precede any `{}` block. The spec refers to this area
+as the at-rule’s “prelude”.
+
+```js
+var root = postcss.parse('@media print, screen {}');
+var media = root.first;
+media.params //=> 'print, screen'
+```
+
+## `Rule` node
+
+Represents a CSS rule: a selector followed by a declaration block.
+
+```js
+var root = postcss.parse('a{}');
+var rule = root.first;
+rule.type //=> 'rule'
+rule.toString() //=> 'a{}'
+```
+
+### `rule.selector`
+
+The rule’s full selector represented as a string. If there are multiple
+comma-separated selectors, the entire group will be included.
+
+```js
+var root = postcss.parse('a, b { }');
+var rule = root.first;
+rule.selector //=> 'a, b'
+```
+
+### `rule.selectors`
+
+An array containing the rule’s individual selectors.
+Groups of selectors are split at commas.
+
+```js
+var root = postcss.parse('a, b { }');
+var rule = root.first;
+
+rule.selector //=> 'a, b'
+rule.selectors //=> ['a', 'b']
+
+rule.selectors = ['a', 'strong'];
+rule.selector //=> 'a, strong'
+```
+
+## `Declaration` node
+
+Represents a CSS declaration.
+
+```js
+var root = postcss.parse('a { color: black }');
+var decl = root.first.first;
+decl.type //=> 'decl'
+decl.toString() //=> ' color: black'
+```
+
+### `declaration.prop`
+
+The declaration’s property name.
+
+```js
+var root = postcss.parse('a { color: black }');
+var decl = root.first.first;
+decl.prop //=> 'color'
+```
+
+### `declaration.value`
+
+The declaration’s value.
+
+```js
+var root = postcss.parse('a { color: black }');
+var decl = root.first.first;
+decl.value //=> 'black'
+```
+
+### `declaration.important`
+
+`true` if the declaration has an `!important` annotation.
+
+```js
+var root = postcss.parse('a { color: black !important; color: white }');
+root.first.first.important //=> true
+root.first.last.important //=> undefined
+```
+
+## `Comment` node
+
+Represents a comment between declarations or statements (rule and at-rules).
+Comments inside selectors, at-rule parameters, or declaration values
+will be stored in the [`Node#raws`] properties explained above.
+
+```js
+var root = postcss.parse('a { color: /* inner */ black; /* outer */ }');
+var decl = root.first.first;
+var comment = root.first.last;
+
+comment.type //=> 'comment'
+decl.between //=> ': /* inner */'
+```
+
+### `comment.text`
+
+The comment’s text.
+
+```js
+var root = postcss.parse('/* Empty file */');
+var comment = root.first;
+var comment.text //=> 'Empty file'
+```
+
+[`source-map`]: https://github.com/mozilla/source-map
+[Promise]: http://www.html5rocks.com/en/tutorials/es6/promises/
+
+[source map options]: https://github.com/postcss/postcss/blob/master/docs/source-maps.md
+
+[`Processor#process(css, opts)`]: #processorprocesscss-opts
+[`Root#toResult(opts)`]: #roottoresultopts
+[`LazyResult#then()`]: #lazythenonfulfilled-onrejected
+[`postcss(plugins)`]: #postcssplugins
+[`postcss.plugin()`]: #postcsspluginname-initializer
+[`Declaration` node]: #declaration-node
+[`Result#messages`]: #resultmessages
+[`CssSyntaxError`]: #csssyntaxerror-class
+[`Processor#use`]: #processoruseplugin
+[`Result#warn()`]: #resultwarntext-opts
+[`Node#warn()`]: #nodewarnresult-message
+[`Comment` node]: #comment-node
+[`AtRule` node]: #atrule-node
+[`from` option]: #processorprocesscss-opts
+[`LazyResult`]: #lazyresult-class
+[`Result#map`]: #resultmap
+[`Result#css`]: #resultcss
+[`Root` node]: #root-node
+[`Rule` node]: #rule-node
+[`Processor`]: #processor-class
+[`Node#raws`]: #noderaws
+[`Warning`]: #warning-class
+[`Result`]: #result-class
+[`Input`]: #inputclass
projects / yaffs-website / blobdiff