yoastseo-dep/src/languageProcessing/helpers/syllables/syllableCountStep.js

Yoast clientside page analysis

import { isUndefined } from "lodash-es";

import arrayToRegex from "../regex/createRegexFromArray.js";

/**
 * Constructs a language syllable regex that contains a regex for matching syllable exclusion.
 *
 * @param {object} syllableRegex The object containing the syllable exclusions.
 * @constructor
 */
const SyllableCountStep = function( syllableRegex ) {
	this._hasRegex = false;
	this._regex = "";
	this._multiplier = "";
	this.createRegex( syllableRegex );
};

/**
 * Returns if a valid regex has been set.
 *
 * @returns {boolean} True if a regex has been set, false if not.
 */
SyllableCountStep.prototype.hasRegex = function() {
	return this._hasRegex;
};

/**
 * Creates a regex based on the given syllable exclusions, and sets the multiplier to use.
 *
 * @param {object} syllableRegex The object containing the syllable exclusions and multiplier.
 * @returns {void}
 */
SyllableCountStep.prototype.createRegex = function( syllableRegex ) {
	if ( ! isUndefined( syllableRegex ) && ! isUndefined( syllableRegex.fragments ) ) {
		this._hasRegex = true;
		this._regex = arrayToRegex( syllableRegex.fragments, true );
		this._multiplier = syllableRegex.countModifier;
	}
};

/**
 * Returns the stored regular expression.
 *
 * @returns {RegExp} The stored regular expression.
 */
SyllableCountStep.prototype.getRegex = function() {
	return this._regex;
};

/**
 * Matches syllable exclusions in a given word and the returns the number found multiplied with the
 * given multiplier.
 *
 * @param {String} word The word to match for syllable exclusions.
 * @returns {number} The amount of syllables found.
 */
SyllableCountStep.prototype.countSyllables = function( word ) {
	if ( this._hasRegex ) {
		const match = word.match( this._regex ) || [];
		return match.length * this._multiplier;
	}
	return 0;
};

export default SyllableCountStep;