mirror of https://github.com/jkjoy/sunpeiwen.git
63 lines
1.7 KiB
JavaScript
63 lines
1.7 KiB
JavaScript
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'use strict';
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const { DomHandler, DomUtils, Parser } = require('htmlparser2');
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const escapeHTML = require('./escape_html');
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const nonWord = /^\s*[^a-zA-Z0-9]\s*$/;
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const parseHtml = html => {
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const handler = new DomHandler(null, {});
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new Parser(handler, {}).end(html);
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return handler.dom;
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};
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const getId = ({ attribs = {}, parent }) => {
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return attribs.id || (!parent ? '' : getId(parent));
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};
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/**
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* Identify a heading that to be unnumbered or not.
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*/
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const isUnnumbered = ({ attribs = {} }) => {
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return attribs['data-toc-unnumbered'] === 'true';
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};
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function tocObj(str, options = {}) {
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const { min_depth, max_depth } = Object.assign({
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min_depth: 1,
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max_depth: 6
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}, options);
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const headingsSelector = ['h1', 'h2', 'h3', 'h4', 'h5', 'h6'].slice(min_depth - 1, max_depth);
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const headings = DomUtils.find(({ tagName }) => headingsSelector.includes(tagName), parseHtml(str), true);
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const headingsLen = headings.length;
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if (!headingsLen) return [];
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const result = [];
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for (let i = 0; i < headingsLen; i++) {
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const el = headings[i];
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const level = +el.name[1];
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const id = getId(el);
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const unnumbered = isUnnumbered(el);
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let text = '';
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for (const element of el.children) {
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const elText = DomUtils.textContent(element);
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// Skip permalink symbol wrapped in <a>
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// permalink is a single non-word character, word = [a-Z0-9]
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// permalink may be wrapped in whitespace(s)
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if (element.name !== 'a' || !nonWord.test(elText)) {
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text += escapeHTML(elText);
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}
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}
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if (!text) text = escapeHTML(DomUtils.textContent(el));
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const res = { text, id, level };
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if (unnumbered) res.unnumbered = true;
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result.push(res);
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}
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return result;
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}
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module.exports = tocObj;
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