Automattic
Juice 
Given HTML, juice will inline your CSS properties into the style attribute.
How to use
Juice has a number of functions based on whether you want to process a file, HTML string, or a cheerio document, and whether you want juice to automatically get remote stylesheets, scripts and image dataURIs to inline.
To inline HTML without getting remote resources, using default options:
var juice = require('juice');
var result = juice("<style>div{color:red;}</style><div/>");
result will be:
<div style="color: red;"></div>
Try out the web client version
What is this useful for ?
- HTML emails. For a comprehensive list of supported selectors see here
- Embedding HTML in 3rd-party websites.
Documentation
Juice is exposed as a standard module, and from CLI with a smaller set of options.
Options
All juice methods take an options object that can contain any of these properties, though not every method uses all of these:
applyAttributesTableElements- whether to create attributes for styles injuice.styleToAttributeon elements set injuice.tableElements. Defaults totrue.applyHeightAttributes- whether to use any CSS pixel heights to createheightattributes on elements set injuice.heightElements. Defaults totrue.applyStyleTags- whether to inline styles in<style></style>Defaults totrue.applyWidthAttributes- whether to use any CSS pixel widths to createwidthattributes on elements set injuice.widthElements. Defaults totrue.decodeStyleAttributes- whether to decode the value ofstyle=attributes. Defaults tofalse.extraCss- extra css to apply to the file. Defaults to"".insertPreservedExtraCss- whether to insert into the document any preserved@mediaor@font-facecontent fromextraCsswhen usingpreserveMediaQueries,preserveFontFacesorpreserveKeyFrames. Whentrueorder of preference to append the<style>element is intohead, thenbody, then at the end of the document. When astringthe value is treated as a CSS/jQuery/cheerio selector, and when found, the<style>tag will be appended to the end of the first match. Defaults totrue.inlinePseudoElements- Whether to insert pseudo elements (::beforeand::after) as<span>into the DOM. Note: Inserting pseudo elements will modify the DOM and may conflict with CSS selectors elsewhere on the page (e.g.,:last-child).preserveFontFaces- preserves all@font-facewithin<style></style>tags as a refinement whenremoveStyleTagsistrue. Other styles are removed. Defaults totrue.preserveImportant- preserves!importantin values. Defaults tofalse.preserveMediaQueries- preserves all media queries (and contained styles) within<style></style>tags as a refinement whenremoveStyleTagsistrue. Other styles are removed. Defaults totrue.preserveKeyFrames- preserves all key frames within<style></style>tags as a refinement whenremoveStyleTagsistrue. Other styles are removed. Defaults totrue.preservePseudos- preserves all rules containing pseudo selectors defined inignoredPseudoswithin<style></style>tags as a refinement whenremoveStyleTagsistrue. Other styles are removed. Defaults totrue.removeStyleTags- whether to remove the original<style></style>tags after (possibly) inlining the css from them. Defaults totrue.resolveCSSVariables- whether to resolve CSS variables. Defaults totrue.webResources- An options object that will be passed to web-resource-inliner for juice functions that will get remote resources (juiceResourcesandjuiceFile). Defaults to{}.xmlMode- whether to output XML/XHTML with all tags closed. Note that the input must also be valid XML/XHTML or you will get undesirable results. Defaults tofalse.
Methods
juice(html [, options])
Returns string containing inlined HTML. Does not fetch remote resources.
html- html string, accepts complete documents as well as fragmentsoptions- optional, see Options above
juice.juiceResources(html, options, callback)
Callback returns string containing inlined HTML. Fetches remote resources.
html- html stringoptions- see Options abovecallback(err, html)err-Errorobject ornullhtml- inlined HTML
juice.juiceFile(filePath, options, callback)
Callback returns string containing inlined HTML. Fetches remote resources.
filePath- path to the html file to be juicedoptions- see Options abovecallback(err, html)err-Errorobject ornullhtml- inlined HTML
juice.juiceDocument($ [, options])
This takes a cheerio instance and performs inlining in-place. Returns the same cheerio instance. Does not fetch remote resources.
$- a cheerio instance, be sure to use the same cheerio version that juice usesoptions- optional, see Options above`
juice.inlineContent(html, css [, options])
This takes html and css and returns new html with the provided css inlined.
It does not look at <style> or <link rel="stylesheet"> elements at all.
html- html stringcss- css stringoptions- optional, see Options above
juice.inlineDocument($, css [, options])
Given a cheerio instance and css, this modifies the cheerio instance so that the provided css is inlined. It does not look at <style> or <link rel="stylesheet"> elements at all.
$- a cheerio instance, be sure to use the same cheerio version that juice usescss- css stringoptions- optional, see Options above
Global settings
juice.codeBlocks
An object where each value has a start and end to specify fenced code blocks that should be ignored during parsing and inlining. For example, Handlebars (hbs) templates are juice.codeBlocks.HBS = {start: '{{', end: '}}'}. codeBlocks can fix problems where otherwise juice might interpret code like <= as HTML, when it is meant to be template language code. Note that codeBlocks is a dictionary which can contain many different code blocks, so don't do juice.codeBlocks = {...} do juice.codeBlocks.myBlock = {...}
juice.ignoredPseudos
Array of ignored pseudo-selectors such as 'hover' and 'active'.
juice.widthElements
Array of HTML elements that can receive width attributes.
juice.heightElements
Array of HTML elements that can receive height attributes.
juice.styleToAttribute
Object of style property names (key) to their respective attribute names (value).
juice.tableElements
Array of table HTML elements that can receive attributes defined in juice.styleToAttribute.
juice.nonVisualElements
Array of elements that will not have styles inlined because they are not intended to render.
juiceClient.excludedProperties
Array of css properties that won't be inlined.
Special markup
data-embed
When a data-embed attribute is present on a stylesheet <link> that has been inlined into the document as a <style></style> tag by the web-resource-inliner juice will not inline the styles and will not remove the <style></style> tags.
This can be used to embed email client support hacks that rely on css selectors into your email templates.
CLI Options
To use Juice from CLI, run juice [options] input.html output.html
For a listing of all available options, just type juice -h.
Note that if you want to just type
juicefrom the command line, you shouldnpm install juice -gso it is globally available.
CLI Options:
The CLI should have all the above options with the names changed from camel case to hyphen-delimited, so for example extraCss becomes extra-css and webResources.scripts becomes web-resources-scripts.
These are additional options not included in the standard juice options listed above:
--css [filepath]will load and inject CSS intoextraCss.--options-file [filepath]will load and inject options from a JSON file. Options from the CLI will be given priority over options in the file when there is a conflict.codeBlocksis optionally supported in the options file if you include it. This will allow you to support different template languages in a build process.
Running Juice in the Browser
Attempting to Browserify require('juice') fails because portions of Juice and its dependencies interact with the file system using the standard require('fs'). However, you can require('juice/client') via Browserify which has support for juiceDocument, inlineDocument, and inlineContent, but not juiceFile, juiceResources, or inlineExternal. Note that automated tests are not running in the browser yet.
License
MIT Licensed, see License.md
3rd-party
- Uses cheerio for the underlying DOM representation.
- Uses mensch to parse out CSS and Slick to tokenize them.
- Icon by UnheardSounds