yoastseo/build/languageProcessing/helpers/html/html.js

Yoast client-side content analysis

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.inlineElements = exports.getBlocks = exports.default = exports.blockElements = void 0;
exports.isBlockElement = isBlockElement;
exports.isInlineElement = isInlineElement;
var _lodash = require("lodash");
var _core = _interopRequireDefault(require("tokenizer2/core"));
function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
const blockElements = exports.blockElements = ["address", "article", "aside", "blockquote", "canvas", "dd", "div", "dl", "fieldset", "figcaption", "figure", "footer", "form", "h1", "h2", "h3", "h4", "h5", "h6", "header", "hgroup", "hr", "li", "main", "nav", "noscript", "ol", "output", "p", "pre", "section", "table", "tfoot", "ul", "video"];
const inlineElements = exports.inlineElements = ["b", "big", "i", "small", "tt", "abbr", "acronym", "cite", "code", "dfn", "em", "kbd", "strong", "samp", "time", "var", "a", "bdo", "br", "img", "map", "object", "q", "script", "span", "sub", "sup", "button", "input", "label", "select", "textarea"];
const blockElementsRegex = new RegExp("^(" + blockElements.join("|") + ")$", "i");
const inlineElementsRegex = new RegExp("^(" + inlineElements.join("|") + ")$", "i");
const blockElementStartRegex = new RegExp("^<(" + blockElements.join("|") + ")[^>]*?>$", "i");
const blockElementEndRegex = new RegExp("^</(" + blockElements.join("|") + ")[^>]*?>$", "i");
const inlineElementStartRegex = new RegExp("^<(" + inlineElements.join("|") + ")[^>]*>$", "i");
const inlineElementEndRegex = new RegExp("^</(" + inlineElements.join("|") + ")[^>]*>$", "i");
const otherElementStartRegex = /^<([^>\s/]+)[^>]*>$/;
const otherElementEndRegex = /^<\/([^>\s]+)[^>]*>$/;
const contentRegex = /^[^<]+$/;
const greaterThanContentRegex = /^<[^><]*$/;
const commentRegex = /<!--(.|[\r\n])*?-->/g;
let tokens = [];
let htmlBlockTokenizer;

/**
 * Creates a tokenizer to tokenize HTML into blocks.
 *
 * @returns {void}
 */
function createTokenizer() {
  tokens = [];
  htmlBlockTokenizer = (0, _core.default)(function (token) {
    tokens.push(token);
  });
  htmlBlockTokenizer.addRule(contentRegex, "content");
  htmlBlockTokenizer.addRule(greaterThanContentRegex, "greater-than-sign-content");
  htmlBlockTokenizer.addRule(blockElementStartRegex, "block-start");
  htmlBlockTokenizer.addRule(blockElementEndRegex, "block-end");
  htmlBlockTokenizer.addRule(inlineElementStartRegex, "inline-start");
  htmlBlockTokenizer.addRule(inlineElementEndRegex, "inline-end");
  htmlBlockTokenizer.addRule(otherElementStartRegex, "other-element-start");
  htmlBlockTokenizer.addRule(otherElementEndRegex, "other-element-end");
}

/**
 * Returns whether or not the given element name is a block element.
 *
 * @param {string} htmlElementName The name of the HTML element.
 * @returns {boolean} Whether or not it is a block element.
 */
function isBlockElement(htmlElementName) {
  return blockElementsRegex.test(htmlElementName);
}

/**
 * Returns whether or not the given element name is an inline element.
 *
 * @param {string} htmlElementName The name of the HTML element.
 * @returns {boolean} Whether or not it is an inline element.
 */
function isInlineElement(htmlElementName) {
  return inlineElementsRegex.test(htmlElementName);
}

/**
 * Splits a text into blocks based on HTML block elements.
 *
 * @param {string} text The text to split.
 * @returns {Array} A list of blocks based on HTML block elements.
 */
function getBlocks(text) {
  const blocks = [];
  let depth = 0,
    blockStartTag = "",
    currentBlock = "",
    blockEndTag = "";

  // Remove all comments because it is very hard to tokenize them.
  text = text.replace(commentRegex, "");
  createTokenizer();
  htmlBlockTokenizer.onText(text);
  htmlBlockTokenizer.end();
  (0, _lodash.forEach)(tokens, function (token, i) {
    const nextToken = tokens[i + 1];
    switch (token.type) {
      case "content":
      case "greater-than-sign-content":
      case "inline-start":
      case "inline-end":
      case "other-tag":
      case "other-element-start":
      case "other-element-end":
      case "greater than sign":
        if (!nextToken || depth === 0 && (nextToken.type === "block-start" || nextToken.type === "block-end")) {
          currentBlock += token.src;
          blocks.push(currentBlock);
          blockStartTag = "";
          currentBlock = "";
          blockEndTag = "";
        } else {
          currentBlock += token.src;
        }
        break;
      case "block-start":
        if (depth !== 0) {
          if (currentBlock.trim() !== "") {
            blocks.push(currentBlock);
          }
          currentBlock = "";
          blockEndTag = "";
        }
        depth++;
        blockStartTag = token.src;
        break;
      case "block-end":
        depth--;
        blockEndTag = token.src;

        /*
         * We try to match the most deep blocks so discard any other blocks that have been started but not
         * finished.
         */
        if ("" !== blockStartTag && "" !== blockEndTag) {
          blocks.push(blockStartTag + currentBlock + blockEndTag);
        } else if ("" !== currentBlock.trim()) {
          blocks.push(currentBlock);
        }
        blockStartTag = "";
        currentBlock = "";
        blockEndTag = "";
        break;
    }

    // Handles HTML with too many closing tags.
    if (depth < 0) {
      depth = 0;
    }
  });
  return blocks;
}
const memoizedGetBlocks = exports.getBlocks = (0, _lodash.memoize)(getBlocks);
var _default = exports.default = {
  blockElements: blockElements,
  inlineElements: inlineElements,
  isBlockElement: isBlockElement,
  isInlineElement: isInlineElement,
  getBlocks: memoizedGetBlocks
};
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