The 'juice' npm package is primarily used for inlining CSS into HTML. This is particularly useful for sending HTML emails where inline styles are often required for consistent rendering across different email clients.
Inline CSS into HTML
This feature allows you to take an HTML string with embedded CSS and inline the CSS styles directly into the HTML elements. This is useful for ensuring that styles are applied correctly in environments that do not support embedded or external stylesheets, such as many email clients.
const juice = require('juice');
const html = '<html><head><style>h1 { color: red; }</style></head><body><h1>Hello, world!</h1></body></html>';
const inlinedHtml = juice(html);
console.log(inlinedHtml);Inline CSS from external stylesheets
This feature allows you to inline CSS from external stylesheets referenced in the HTML. The 'url' option is used to resolve the paths of the external stylesheets.
const juice = require('juice');
const html = '<html><head><link rel="stylesheet" href="styles.css"></head><body><h1>Hello, world!</h1></body></html>';
const inlinedHtml = juice(html, { url: 'http://example.com' });
console.log(inlinedHtml);Custom CSS inlining options
Juice provides various options to customize the inlining process. For example, you can choose whether to apply style tags, remove style tags after inlining, and more.
const juice = require('juice');
const html = '<html><head><style>h1 { color: red; }</style></head><body><h1>Hello, world!</h1></body></html>';
const options = { applyStyleTags: true, removeStyleTags: false };
const inlinedHtml = juice(html, options);
console.log(inlinedHtml);The 'inline-css' package is another tool for inlining CSS into HTML. It offers similar functionality to 'juice' but with a simpler API. It is useful for basic inlining tasks but may lack some of the advanced options available in 'juice'.
The 'premailer' package is a more comprehensive tool that not only inlines CSS but also rewrites URLs, adds missing HTML attributes, and more. It is a good alternative to 'juice' for more complex email preparation tasks.
The 'email-comb' package is designed to clean and optimize HTML emails by inlining CSS and removing unused styles. It is similar to 'juice' but focuses more on optimization and cleaning up the HTML.
Given HTML, juice will inline your CSS properties into the style attribute.
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
Juice is exposed as a standard module, and from CLI with a smaller set of 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 in juice.styleToAttribute on elements set in juice.tableElements. Defaults to true.
applyHeightAttributes - whether to use any CSS pixel heights to create height attributes on elements set in juice.heightElements. Defaults to true.
applyStyleTags - whether to inline styles in <style></style> Defaults to true.
applyWidthAttributes - whether to use any CSS pixel widths to create width attributes on elements set in juice.widthElements. Defaults to true.
extraCss - extra css to apply to the file. Defaults to "".
insertPreservedExtraCss - whether to insert into the document any preserved @media or @font-face content from extraCss when using preserveMediaQueries, preserveFontFaces or preserveKeyFrames. When true order of preference to append the <style> element is into head, then body, then at the end of the document. When a string the 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 to true.
inlinePseudoElements - Whether to insert pseudo elements (::before and ::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-face within <style></style> tags as a refinement when removeStyleTags is true. Other styles are removed. Defaults to true.
preserveImportant - preserves !important in values. Defaults to false.
preserveMediaQueries - preserves all media queries (and contained styles) within <style></style> tags as a refinement when removeStyleTags is true. Other styles are removed. Defaults to true.
preserveKeyFrames - preserves all key frames within <style></style> tags as a refinement when removeStyleTags is true. Other styles are removed. Defaults to true.
preservePseudos - preserves all rules containing pseudo selectors defined in ignoredPseudos within <style></style> tags as a refinement when removeStyleTags is true. Other styles are removed. Defaults to true.
removeStyleTags - whether to remove the original <style></style> tags after (possibly) inlining the css from them. Defaults to true.
resolveCSSVariables - whether to resolve CSS variables. Defaults to true.
webResources - An options object that will be passed to web-resource-inliner for juice functions that will get remote resources (juiceResources and juiceFile). 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 to false.
Returns string containing inlined HTML. Does not fetch remote resources.
html - html string, accepts complete documents as well as fragmentsoptions - optional, see Options aboveCallback returns string containing inlined HTML. Fetches remote resources.
html - html stringoptions - see Options abovecallback(err, html)
err - Error object or nullhtml - inlined HTMLCallback returns string containing inlined HTML. Fetches remote resources.
filePath - path to the html file to be juicedoptions - see Options abovecallback(err, html)
err - Error object or nullhtml - inlined HTMLThis 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`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 aboveGiven 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 aboveAn 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 = {...}
Array of ignored pseudo-selectors such as 'hover' and 'active'.
Array of HTML elements that can receive width attributes.
Array of HTML elements that can receive height attributes.
Object of style property names (key) to their respective attribute names (value).
Array of table HTML elements that can receive attributes defined in juice.styleToAttribute.
Array of elements that will not have styles inlined because they are not intended to render.
Array of css properties that won't be inlined.
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.
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 into extraCss.--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.codeBlocks is optionally supported in the options file if you include it. This will allow you to support different template languages in a build process.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.
MIT Licensed, see License.md
FAQs
Inlines css into html source
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