@emmetio/html-matcher

Small and fast HTML matcher

Finds matching opening and closing tag pair for given location in HTML/XML source:

import match from '@emmetio/html-matcher';

const content = '<div><a href="http://emmet.io">Example</a></div>';

// Find tag pair at character 35
const tag = match(content, 35);

console.log(tag.name); // Name of matched tag: "a"
console.log(tag.open); // Range of opening tag: [5, 31]
console.log(tag.end); // Range of closing tag: [38, 42]

// List of attributes found in opening tag
console.log(tag.attributes);

By default, matcher works in HTML, which means if it finds tag name which is known to be empty (for example, <img>) it will not search for it’s closing part. However, such behavior might be unexpected for XML syntaxes where all tags should be either self-closed or provide closing part. In this case, you should pass xml: true option to properly handle XML mode:

import match from '@emmetio/html-matcher';

const content = '<div><img>Caption</img></div>';
const html = match(content, 8);
const xml = match(content, 8, { xml: true });

console.log(html.name); // "img"
console.log(html.open); // [5, 10]
console.log(html.close); // undefined

console.log(xml.name); // "img"
console.log(xml.open); // [5, 10]
console.log(xml.close); // [17, 23]

Special tags

In HTML, some tags has special meaning. For example, a <script> tag: its contents should be completely ignored until we find closing </script> tag. But, if <script> tag contains unknown type attribute value, we should consider it as a regular tag. By default, matcher understands script and style tags as “special” but you can override them with special option:

import match from '@emmetio/html-matcher';

// Treat `<foo-bar>` tag as ”special”: skip its content until `</foo-bar>`. Note that this option overwrites default value with `['script', 'style']` value
match('...', 10, { special: { 'foo-bar': null } });

The special option is an object where key is a tag name and value is an array of type attribute values which, if present in tag, will make it special. If array is not provided, all instances of tag with given name will be considered as special.