geolocation.js

geolocation.js

define('geolocation', [], function(require, module, exports){
    /*
     * @Name: Geolocation
     * @Overview: the javascript way to fetch the geolocation
     * @Author: sofish Lin <http://sofish.de>
     */
    
    // TODO: error handler for ie
    
    function geo(successCallback, errorCallback) {
        
        var that = this,
        
            // native geolocation API
            _w3cAPI = navigator.geolocation;
        
        // get ip-base geolocation
        // fallback for the w3c way
        function _ipBaseWay(){
            var that = this;
            
            var doc = document,
                script = doc.createElement('script');
                
            script.setAttribute('src','http://j.maxmind.com/app/geoip.js');
            doc.body.appendChild(script);
            
            script.attachEvent('onreadystatechange', function(){
                var target = window.event.srcElement;
                if(/loaded|complete/.test(target.readyState)){
                    var coords = {
                        latitude: geoip_latitude(),
                        longitude: geoip_longitude()
                    };
                    return successCallback.call(that, coords);
                }
            });
        };
            
        // fetch coords using w3c Geoloactions API
        function _w3cWay (){
            var that = this;
            
            _w3cAPI.getCurrentPosition(function(position){
                successCallback.call(that, position.coords);
            },function(error){
                var err;
                switch (error.code) {
                    case error.PERMISSION_DENIED:
                    	err = 'You did not share geolocation data!'; break;
                    case error.POSITION_UNAVAILABLE:
                    	err = 'Could not detect current position!'; break;
                    case error.TIMEOUT:
                    	err = 'Retrieving position timedout!'; break;
                    default:
                    	err = 'Unknown error';
                };
                errorCallback.call(that, err);
            });
    
        };
                
        // create the position
        !!(_w3cAPI) ? _w3cWay() : _ipBaseWay();  
    };
    
    module.exports = geo;
    
})