+++ /dev/null
-# postcss-media-query-parser\r
-\r
-[](https://www.npmjs.com/package/postcss-media-query-parser) [](https://travis-ci.org/dryoma/postcss-media-query-parser)\r
-\r
-Media query parser with very simple traversing functionality.\r
-\r
-## Installation and usage\r
-\r
-First install it via NPM:\r
-\r
-```\r
-npm install postcss-media-query-parser\r
-```\r
-\r
-Then in your Node.js application:\r
-\r
-```js\r
-import mediaParser from "postcss-media-query-parser";\r
-\r
-const mediaQueryString = "(max-width: 100px), not print";\r
-const result = mediaParser(mediaQueryString);\r
-```\r
-\r
-The `result` will be this object:\r
-\r
-```js\r
-{\r
- type: 'media-query-list',\r
- value: '(max-width: 100px), not print',\r
- after: '',\r
- before: '',\r
- sourceIndex: 0,\r
-\r
- // the first media query\r
- nodes: [{\r
- type: 'media-query',\r
- value: '(max-width: 100px)',\r
- before: '',\r
- after: '',\r
- sourceIndex: 0,\r
- parent: <link to parent 'media-query-list' node>,\r
- nodes: [{\r
- type: 'media-feature-expression',\r
- value: '(max-width: 100px)',\r
- before: '',\r
- after: '',\r
- sourceIndex: 0,\r
- parent: <link to parent 'media-query' node>,\r
- nodes: [{\r
- type: 'media-feature',\r
- value: 'max-width',\r
- before: '',\r
- after: '',\r
- sourceIndex: 1,\r
- parent: <link to parent 'media-feature-expression' node>,\r
- }, {\r
- type: 'colon',\r
- value: ':',\r
- before: '',\r
- after: ' ',\r
- sourceIndex: 10,\r
- parent: <link to parent 'media-feature-expression' node>,\r
- }, {\r
- type: 'value',\r
- value: '100px',\r
- before: ' ',\r
- after: '',\r
- sourceIndex: 12,\r
- parent: <link to parent 'media-feature-expression' node>,\r
- }]\r
- }]\r
- },\r
- // the second media query\r
- {\r
- type: 'media-query',\r
- value: 'not print',\r
- before: ' ',\r
- after: '',\r
- sourceIndex: 20,\r
- parent: <link to parent 'media-query-list' node>,\r
- nodes: [{\r
- type: 'keyword',\r
- value: 'not',\r
- before: ' ',\r
- after: ' ',\r
- sourceIndex: 20,\r
- parent: <link to parent 'media-query' node>,\r
- }, {\r
- type: 'media-type',\r
- value: 'print',\r
- before: ' ',\r
- after: '',\r
- sourceIndex: 24,\r
- parent: <link to parent 'media-query' node>,\r
- }]\r
- }]\r
-}\r
-```\r
-\r
-One of the likely sources of a string to parse would be traversing [a PostCSS container node](http://api.postcss.org/Root.html) and getting the `params` property of nodes with the name of "atRule":\r
-\r
-```js\r
-import postcss from "postcss";\r
-import mediaParser from "postcss-media-query-parser";\r
-\r
-const root = postcss.parse(<contents>);\r
-// ... or any other way to get sucn container\r
-\r
-root.walkAtRules("media", (atRule) => {\r
- const mediaParsed = mediaParser(atRule.params);\r
- // Do something with "mediaParsed" object\r
-});\r
-```\r
-\r
-## Nodes\r
-\r
-Node is a very generic item in terms of this parser. It's is pretty much everything that ends up in the parsed result. Each node has these properties:\r
-\r
-* `type`: the type of the node (see below);\r
-* `value`: the node's value stripped of trailing whitespaces;\r
-* `sourceIndex`: 0-based index of the node start relative to the source start (excluding trailing whitespaces);\r
-* `before`: a string that contain a whitespace between the node start and the previous node end/source start;\r
-* `after`: a string that contain a whitespace between the node end and the next node start/source end;\r
-* `parent`: a link to this node's parent node (a container).\r
-\r
-A node can have one of these types (according to [the 2012 CSS3 standard](https://www.w3.org/TR/2012/REC-css3-mediaqueries-20120619/)):\r
-\r
-* `media-query-list`: that is the root level node of the parsing result. A [container](#containers); its children can have types of `url` and `media-query`.\r
-* `url`: if a source is taken from a CSS `@import` rule, it will have a `url(...)` function call. The value of such node will be `url(http://uri-address)`, it is to be parsed separately.\r
-* `media-query`: such nodes correspond to each media query in a comma separated list. In the exapmle above there are two. Nodes of this type are [containers](#containers).\r
-* `media-type`: `screen`, `tv` and other media types.\r
-* `keyword`: `only`, `not` or `and` keyword.\r
-* `media-feature-expression`: an expression in parentheses that checks for a condition of a particular media feature. The value would be like this: `(max-width: 1000px)`. Such nodes are [containers](#containers). They always have a `media-feature` child node, but might not have a `value` child node (like in `screen and (color)`).\r
-* `media-feature`: a media feature, e.g. `max-width`.\r
-* `colon`: present if a media feature expression has a colon (e.g. `(min-width: 1000px)`, compared to `(color)`).\r
-* `value`: a media feature expression value, e.g. `100px` in `(max-width: 1000px)`.\r
-\r
-### Parsing details\r
-\r
-postcss-media-query-parser allows for cases of some **non-standard syntaxes** and tries its best to work them around. For example, in a media query from a code with SCSS syntax:\r
-\r
-```scss\r
-@media #{$media-type} and ( #{"max-width" + ": 10px"} ) { ... }\r
-```\r
-\r
-`#{$media-type}` will be the node of type `media-type`, alghough `$media-type`'s value can be `only screen`. And inside `media-feature-expression` there will only be a `media-feature` type node with the value of `#{"max-width" + ": 10px"}` (this example doesn't make much sense, it's for demo purpose).\r
-\r
-But the result of parsing **malformed media queries** (such as with incorrect amount of closing parens, curly braces, etc.) can be unexpected. For exapmle, parsing:\r
-\r
-```scss\r
-@media ((min-width: -100px)\r
-```\r
-\r
-would return a media query list with the single `media-query` node that has no child nodes.\r
-\r
-## Containers\r
-\r
-Containers are [nodes](#nodes) that have other nodes as children. Container nodes have an additional property `nodes` which is an array of their child nodes. And also these methods:\r
-\r
-* `each(callback)` - traverses the direct child nodes of a container, calling `callback` function for each of them. Returns `false` if traversing has stopped by means of `callback` returning `false`, and `true` otherwise.\r
-* `walk([filter, ]callback)` - traverses ALL descendant nodes of a container, calling `callback` function for each of them. Returns `false` if traversing has stopped by means of `callback` returning `false`, and `true` otherwise.\r
-\r
-In both cases `callback` takes these parameters:\r
-\r
-- `node` - the current node (one of the container's descendats, that the callback has been called against).\r
-- `i` - 0-based index of the `node` in an array of its parent's children.\r
-- `nodes` - array of child nodes of `node`'s parent.\r
-\r
-If `callback` returns `false`, the traversing stops.\r
-\r
-## License\r
-\r
-MIT\r
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