94 lines
2.3 KiB
JavaScript
94 lines
2.3 KiB
JavaScript
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/**
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* Constants
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*/
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const STRING = 'string';
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const NUMBER = 'number';
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const FUNCTION = 'function';
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const OBJECT = 'object';
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export class Metadata {
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/**
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* Constructor and Instance Methods
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*/
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constructor(data) {
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// Define the main "_data" private property as an immutable property.
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// IMPORTANT: This property can only be set during instance construction.
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Object.defineProperty(this, '_data', {
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configurable: false,
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enumerable: false,
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writable: false,
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value: data
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});
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// Define _custom properties as an immutable property
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// IMPORTANT: This property can only be set during instance construction.
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Object.defineProperty(this, '_custom', {
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configurable: false,
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enumerable: false,
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writable: false,
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value: Object.create(null)
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});
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}
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getData() {
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return this._data;
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}
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getDataProperty(propertyName) {
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let propertyValue;
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const _data = this._data;
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if (_data instanceof Object || typeof _data === OBJECT && _data !== null) {
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propertyValue = _data[propertyName];
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}
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return propertyValue;
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}
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/**
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* Set custom attribute value
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* @param {String} attribute Custom attribute name
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* @param {Any} value Custom attribute value
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*/
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setCustomAttribute(attribute, value) {
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this._custom[attribute] = value;
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}
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/**
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* Get custom attribute value
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* @param {String} attribute Custom attribute name
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* @return {Any} Custom attribute value
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*/
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getCustomAttribute(attribute) {
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return this._custom[attribute];
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}
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/**
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* Check if a custom attribute exists
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* @param {String} attribute Custom attribute name
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* @return {Boolean} True if custom attribute exists or false if not
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*/
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customAttributeExists(attribute) {
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return attribute in this._custom;
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}
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/**
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* Static Methods
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*/
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static isValidUID(uid) {
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return typeof uid === STRING && uid.length > 0;
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}
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static isValidIndex(index) {
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return typeof index === NUMBER && index >= 0 && (index | 0) === index;
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}
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static isValidCallback(callback) {
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return typeof callback === FUNCTION;
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}
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}
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