wikimedia/mediawiki-extensions-Wikibase

( function () {
    'use strict';

    var EntityIdPlainFormatter = require( './EntityIdPlainFormatter.js' );

    /**
     * @param {EntityIdPlainFormatter} entityIdFormatter
     */
    module.exports = util.inherit(
        'CachingEntityIdPlainFormatter',
        EntityIdPlainFormatter,
        function ( entityIdFormatter ) {
            this._entityIdFormatter = entityIdFormatter;
            this._cache = {};
        },
        {
            _entityIdFormatter: null,

            _cache: null,

            format: function ( entityId ) {
                if ( !Object.prototype.hasOwnProperty.call( this._cache, entityId ) ) {
                    this._cache[ entityId ] = this._entityIdFormatter.format( entityId );
                }
                return this._cache[ entityId ];
            }

        }
    );
}() );