wikimedia/mediawiki-extensions-Wikibase

/**
 * @license GPL-2.0-or-later
 */
( function () {

    /**
     * @param {Object} entityLoadedHook
     * @param {EntityStore} entityStore
     */
    function PropertyDataTypeStore( entityLoadedHook, entityStore ) {
        this._entityLoadedHook = entityLoadedHook;
        this._entityStore = entityStore;
        this._propertyDataTypeMapping = {};
    }

    $.extend( PropertyDataTypeStore.prototype, {
        /**
         * @type {Object} map of property id to data type
         */
        _propertyDataTypeMapping: {},

        /**
         * @type {Object}
         */
        _entityLoadedHook: null,

        /**
         * @type {EntityStore}
         */
        _entityStore: null,

        setDataTypeForProperty: function ( id, dataType ) {
            this._propertyDataTypeMapping[ id ] = dataType;
        },

        getDataTypeForProperty: function ( id ) {
            var self = this;

            if ( this._propertyDataTypeMapping[ id ] ) {
                return $.Deferred().resolve( this._propertyDataTypeMapping[ id ] );
            }

            return this._getDataTypeFromExistingStatements( id )
                .catch( this._getDataTypeFromEntityStore.bind( this, id ) )
                .always( function ( dataType ) {
                    self.setDataTypeForProperty( id, dataType );
                } );
        },

        _getDataTypeFromExistingStatements: function ( propertyId ) {
            var dataTypePromise = $.Deferred(),
                self = this;

            this._entityLoadedHook.add( function ( entity ) {
                var dataType = self._findDataTypeInEntity( entity, propertyId );
                if ( dataType ) {
                    dataTypePromise.resolve( dataType );
                } else {
                    dataTypePromise.reject();
                }
            } );

            return dataTypePromise;
        },

        /**
         * Recursively traverses (pieces of) entity JSON and returns a property's data type if there is a statement for
         * it on the entity.
         *
         * @param {Object} node
         * @param {string} propertyId
         *
         * @return {null|string}
         */
        _findDataTypeInEntity: function ( node, propertyId ) {
            if ( !node || typeof node !== 'object' ) {
                return null;
            }

            for ( var i in node ) {
                if ( i === propertyId ) {
                    var dataTypeFromSnak = this._getDataTypeFromSnak( node[ i ][ 0 ] ); // may not exist (T249206)
                    if ( dataTypeFromSnak ) {
                        return dataTypeFromSnak;
                    }
                }

                var dataType = this._findDataTypeInEntity( node[ i ], propertyId );
                if ( dataType ) {
                    return dataType;
                }
            }

            return null;
        },

        _getDataTypeFromSnak: function ( snak ) {
            return snak && snak.datatype || // if it's a qualifier/reference, the data type is at the top level
                snak.mainsnak && snak.mainsnak.datatype; // main snak
        },

        _getDataTypeFromEntityStore: function ( propertyId ) {
            return this._entityStore.get( propertyId ).then( function ( property ) {
                if ( !property ) {
                    return null;
                }

                return property.getDataTypeId();
            } );
        }
    } );

    module.exports = PropertyDataTypeStore;

}() );