wikimedia/mediawiki-extensions-Wikibase

/**
 * @license GPL-2.0-or-later
 *
 * @author Adrian Heine <adrian.heine@wikimedia.de>
 * @author H. Snater < mediawiki@snater.com >
 */
( function ( wb ) {
    'use strict';

    var config = require( './config.json' ),
        serialization = require( 'wikibase.serialization' );

    /**
     * Entity initializer.
     * Deserializes the entity passed to JavaScript via mw.config variable or
     * as entity object promise.
     *
     * @constructor
     *
     * @param {string|Thenable} arg Config variable name or entity object promise
     *
     * @throws {Error} if required parameter is not specified properly.
     */
    var EntityInitializer = wb.EntityInitializer = function ( arg ) {
        var entityPromise;
        if ( typeof arg === 'string' ) {
            entityPromise = getFromConfig( arg );
        } else if ( isThenable( arg ) ) {
            entityPromise = arg;
        } else {
            throw new Error(
                'Config variable name or entity promise needs to be specified'
            );
        }

        this._entityPromise = entityPromise;
    };

    EntityInitializer.newFromEntityLoadedHook = function () {
        var entityPromise = $.Deferred( function ( deferred ) {
            mw.hook( 'wikibase.entityPage.entityLoaded' ).add( function ( entity ) {
                deferred.resolve( entity );
            } );
        } ).promise();

        return new EntityInitializer( entityPromise );
    };

    $.extend( EntityInitializer.prototype, {

        /**
         * @type {jQuery.Promise} Promise for serialized entity
         */
        _entityPromise: null,

        /**
         * Retrieves an entity from mw.config.
         *
         * @return {Object} jQuery Promise
         *         Resolved parameters:
         *         - {wikibase.datamodel.Entity}
         *         No rejected parameters.
         */
        getEntity: function () {
            var self = this;

            return this._entityPromise.then( function ( entity ) {
                return self._getDeserializer().then( function ( entityDeserializer ) {
                    return entityDeserializer.deserialize( entity );
                } );
            } );
        },

        /**
         * @return {Object} jQuery promise
         *         Resolved parameters:
         *         - {serialization.EntityDeserializer}
         *         No rejected parameters.
         */
        _getDeserializer: function () {
            var entityDeserializer = new serialization.EntityDeserializer(),
                deferred = $.Deferred();

            var entityTypes = config.entityTypes;
            var modules = [];
            var typeNames = [];
            entityTypes.types.forEach( function ( type ) {
                var deserializerFactoryFunction = entityTypes[ 'deserializer-factory-functions' ][ type ];
                if ( deserializerFactoryFunction ) {
                    modules.push( deserializerFactoryFunction );
                    typeNames.push( type );
                }
            } );
            mw.loader.using( modules, function ( require ) {
                modules.forEach( function ( module, index ) {
                    entityDeserializer.registerStrategy(
                        // eslint-disable-next-line security/detect-non-literal-require
                        require( module )(),
                        typeNames[ index ]
                    );
                } );

                deferred.resolve( entityDeserializer );
            } );
            return deferred.promise();
        }
    } );

    function isThenable( arg ) {
        return typeof arg === 'object' && typeof arg.then === 'function';
    }

    /**
     * Get entity from config
     *
     * @param configVarName
     * @return {jQuery.Promise}
     *         Resolved parameters:
     *         - {object} Entity object
     *         No rejected parameters.
     */
    function getFromConfig( configVarName ) {
        return $.Deferred( function ( deferred ) {
            mw.hook( 'wikipage.content' ).add( function () {
                var serializedEntity = mw.config.get( configVarName );

                if ( serializedEntity === null ) {
                    deferred.reject();
                    return;
                }

                deferred.resolve( JSON.parse( serializedEntity ) );
            } );
        } ).promise();
    }

}( wikibase ) );