gistfile1.js

// *** YQLSync *** //

YQLSync = function(){};
YQLSync.prototype = {

    query : '',
    cache : new Y.CacheOffline,
    
    buildQuery : function () {
        return sub(this.query, { id: this.get('id') });
    },
    
    sync : function (action, options, callback) {
        if (action !== 'read') { return callback(null); }
        
        var query   = this.buildQuery(options),
            cache   = this.cache,
            results = cache.retrieve(query);
        
        // return cached results if we got ’em
        if (results) { return callback(null, results.response); }
        
        Y.YQL(query, function(r){
            if (r.error) {
                callback(r.error, r);
            } else {
                results = r.query.results;
                cache.add(query, results);
                callback(null, results);
            }
        });
    }

};

// *** Place *** //

Place = Y.Base.create('place', Y.Model, [YQLSync], {

    idAttribute : 'woeid',
    queries     : {
        placeFromId     : 'SELECT * FROM geo.places WHERE woeid={id}',
        placeFromLatLon : 'SELECT * FROM geo.places WHERE woeid in ' +
                          '(SELECT place.woeid FROM flickr.places WHERE lat={latitude} AND lon={longitude})',
        placeFromPlaces : 'SELECT * FROM geo.places.common WHERE woeid1={woeid1} AND woeid2={woeid2}'
    },
    
    buildQuery : function (options) {
        options || (options = {});
        
        if (options.woeid1 && options.woeid2) {
            // load the place in common to these two places
            return sub(this.queries.placeFromPlaces, {
                woeid1 : woeid1,
                woeid2 : woeid2
            });
        }
        
        if (this.isNew()) {
            // assume we have a lat/lon
            return sub(this.queries.placeFromLatLon, {
                latitude    : this.get('latitude'),
                longitude   : this.get('longitude')
            });
        }
        
        return sub(this.queries.placeFromId, { id: this.get('id') });
    },
    
    parse : function (results) {
        if ( ! results) { return; }
        var data        = results.place,
            country     = data.country,
            region      = data.admin1,
            locality    = data.locality1;
        
        return {
            woeid       : data.woeid,
            centroid    : data.centroid,
            boundingBox : data.boundingBox,
            country     : country && country.content,
            region      : region && region.content,
            locality    : locality && locality.content
        };
    },
    
    toString : function () {
        var country     = this.get('country'),
            region      = this.get('region'),
            locality    = this.get('locality');
        
        if (locality) { return (locality + ', ' + region); }
        if (region) { return (region + ', ' + country); }
        return country || '';
    }

}, {
    ATTRS : {
        woeid       : {},
        country     : {},
        region      : {},
        locality    : {},
        latitude    : {},
        longitude   : {}
    },
    
    getCommonPlace : function (place1, place2, callback) {
        place1 instanceof Place || (place1 = new Place(place1));
        place2 instanceof Place || (place2 = new Place(place2));
        callback || (callback = function(){});
        
        function loadCommonPlace () {
            var place = new Place().load({
                woeid1 : place1.get('id'),
                woeid2 : place2.get('id')
            }, function(){
                callback(place);
            });
        }
        
        if (place1.isNew()) {
            place1.load(function(){
                if (place2.isNew()) {
                    place2.load(loadCommonPlace);
                } else {
                    loadCommonPlace();
                }
            });
            return;
        }
        
        if (place2.isNew()) {
            place2.load(loadCommonPlace);
            return;
        }
        
        return loadCommonPlace();
    }
});

// Usage

Place.getCommonPlace({
    latitude    : 42.35128040403806,
    longitude   : -71.07214606708988
}, {
    latitude    : 42.363965387785505,
    longitude   : -71.05068839497073
}, function(place){
    place.get('locality'); //=> Boston
});