Source: adapters/abstract-lookup-adapter.js

  1. 'use strict';
  3. /**
  4.  * Adapter that, given a URL, looks up metadata that can identify a review
  5.  * subject, such as a book's title or a restauraunt name.
  6.  *
  7.  * @abstract
  8.  */
  9. class AbstractLookupAdapter {
  11.   /**
  12.    * Lookup adapters return a limited set of data that's displayed to the
  13.    * user. Lookup results take the following form. Note that strings are stored
  14.    * only in one language; the backend adapter performs the full lookup of all
  15.    * available translations.
  16.    *
  17.    * @typedef {Object} LookupResult
  18.    * @property {Object} data
  19.    *  data for this result
  20.    * @property {String} data.label
  21.    *  name to be rendered for this result
  22.    * @property {String} [data.subtitle]
  23.    *  subtitle to be shown below label
  24.    * @property {String} [data.description]
  25.    *  short textual description
  26.    * @property {Thing} [data.thing]
  27.    *  native object representing the review subject, used by native lookup adapter
  28.    * @property {String} sourceID
  29.    *  canonical source that identifies this adapter
  30.    */
  32.   /**
  33.    * @param {Function} updateCallback - `(optional)` callback to run after a
  34.    *  successful lookup
  35.    */
  36.   constructor(updateCallback) {
  37.     // Replace w/ new.target after upgrading to Babel 7.0
  38.     if (this.constructor.name === AbstractLookupAdapter.name)
  39.       throw new TypeError('AbstractAdapter is an abstract class, please instantiate a derived class.');
  41.     this.updateCallback = updateCallback || null;
  43.     /**
  44.      * Canonical identifier for this source. Lower-case string, no whitespace.
  45.      *
  46.      * @type {String}
  47.      */
  48.     this.sourceID = undefined;
  50.     /**
  51.      * RegExp for URLs this adapter can handle.
  52.      *
  53.      * @type {RegExp}
  54.      */
  55.     this.supportedPattern = undefined;
  56.   }
  58.   /**
  59.    * Does this adapter support the given URL? By default, performs a simple
  60.    * regex check.
  61.    *
  62.    * @param {String} url
  63.    *  the URL to test
  64.    * @returns {Boolean}
  65.    *  true if supported
  66.    */
  67.   ask(url) {
  68.     return this.supportedPattern.test(url);
  69.   }
  71.   /**
  72.    * Perform a lookup for a given URL.
  73.    *
  74.    * @abstract
  75.    * @param {String} _url
  76.    *  the URL to perform lookup for
  77.    * @returns {Promise}
  78.    *  promise that resolves with a result object of the form
  79.    *  {@link LookupResult} on success, and rejects with an error on failure
  80.    *
  81.    */
  82.   lookup(_url) {
  83.     return Promise.reject(new Error('Not implemented.'));
  84.   }
  86.   /**
  87.    * Return the canonical source identifier for this adapter
  88.    *
  89.    * @returns {String}
  90.    */
  91.   getSourceID() {
  92.     return this.sourceID || 'no source ID defined';
  93.   }
  95. }
  97. module.exports = AbstractLookupAdapter;