htmlnano
Version:
Modular HTML minifier, built on top of the PostHTML
344 lines (341 loc) • 6.17 kB
JavaScript
import { isEventHandler } from '../helpers.mjs';
const attributesWithLists = new Map([
[
'class',
new Set()
],
[
'dropzone',
new Set()
],
[
'rel',
new Set()
],
[
'ping',
new Set()
],
[
'sandbox',
new Set()
],
/**
* https://github.com/maltsev/htmlnano/issues/180
* https://developer.mozilla.org/en-US/docs/Web/HTML/Element/link#attr-sizes
*
* "sizes" of <img> should not be modified, while "sizes" of <link> is a list of tokens.
*/ [
'sizes',
new Set([
'link'
])
],
[
'headers',
new Set()
] // td, th
]);
function isListAttribute(attrName, tagName) {
const attrKey = attrName.toLowerCase();
const tagSet = attributesWithLists.get(attrKey);
if (!tagSet) {
return false;
}
if (tagSet.size === 0) {
return true;
}
if (!tagName) {
return false;
}
return tagSet.has(tagName.toLowerCase());
}
/** empty set means the attribute is alwasy trimmable */ const attributesWithSingleValue = new Map([
[
'accept',
new Set([
'input'
])
],
[
'action',
new Set([
'form'
])
],
[
'accesskey',
new Set()
],
[
'accept-charset',
new Set([
'form'
])
],
[
'cite',
new Set([
'blockquote',
'del',
'ins',
'q'
])
],
[
'cols',
new Set([
'textarea'
])
],
[
'colspan',
new Set([
'td',
'th'
])
],
[
'data',
new Set([
'object'
])
],
[
'dropzone',
new Set()
],
[
'formaction',
new Set([
'button',
'input'
])
],
[
'height',
new Set([
'canvas',
'embed',
'iframe',
'img',
'input',
'object',
'video'
])
],
[
'high',
new Set([
'meter'
])
],
[
'href',
new Set([
'a',
'area',
'base',
'link'
])
],
[
'itemid',
new Set()
],
[
'low',
new Set([
'meter'
])
],
[
'manifest',
new Set([
'html'
])
],
[
'max',
new Set([
'meter',
'progress'
])
],
[
'maxlength',
new Set([
'input',
'textarea'
])
],
[
'media',
new Set([
'source'
])
],
[
'min',
new Set([
'meter'
])
],
[
'minlength',
new Set([
'input',
'textarea'
])
],
[
'optimum',
new Set([
'meter'
])
],
[
'ping',
new Set([
'a',
'area'
])
],
[
'poster',
new Set([
'video'
])
],
[
'profile',
new Set([
'head'
])
],
[
'rows',
new Set([
'textarea'
])
],
[
'rowspan',
new Set([
'td',
'th'
])
],
[
'size',
new Set([
'input',
'select'
])
],
[
'span',
new Set([
'col',
'colgroup'
])
],
[
'src',
new Set([
'audio',
'embed',
'iframe',
'img',
'input',
'script',
'source',
'track',
'video'
])
],
[
'start',
new Set([
'ol'
])
],
[
'step',
new Set([
'input'
])
],
[
'style',
new Set()
],
[
'tabindex',
new Set()
],
[
'usemap',
new Set([
'img',
'object'
])
],
[
'value',
new Set([
'li',
'meter',
'progress'
])
],
[
'width',
new Set([
'canvas',
'embed',
'iframe',
'img',
'input',
'object',
'video'
])
]
]);
function isSingleValueAttribute(attrName, tagName) {
const attrKey = attrName.toLowerCase();
const tagSet = attributesWithSingleValue.get(attrKey);
if (!tagSet) {
return false;
}
if (!tagName) {
return false;
}
if (tagSet.size === 0) {
return true;
}
return tagSet.has(tagName.toLowerCase());
}
/** Collapse whitespaces inside list-like attributes (e.g. class, rel) */ const mod = {
onAttrs () {
return (attrs, node)=>{
const newAttrs = attrs;
const tagName = node.tag ? node.tag.toLowerCase() : undefined;
Object.entries(attrs).forEach(([attrName, attrValue])=>{
if (typeof attrValue !== 'string') return;
const attrNameLower = attrName.toLowerCase();
if (isListAttribute(attrNameLower, tagName)) {
newAttrs[attrName] = attrValue.replace(/\s+/g, ' ').trim();
return;
}
if (isEventHandler(attrName)) {
newAttrs[attrName] = attrValue.trim();
} else if (isSingleValueAttribute(attrNameLower, tagName)) {
newAttrs[attrName] = attrValue.trim();
}
});
return newAttrs;
};
}
};
export { attributesWithLists, attributesWithSingleValue, mod as default, isListAttribute, isSingleValueAttribute };