callback function not working - javascript

I've created a script that places a marker on a map based on the area you click your mouse over. Once that marker is placed, when your mouse hovers over the marker, an infobox should appear with the address of where the marker is placed. However, the infobox isn't showing up because when I call "info_text", it returns undefined. I realized that I needed to add in a callback function but I don't think I'm implementing it correctly. Could anyone help me fix my code? Thanks
My code:
var geocoder;
function initialize()
{
geocoder = new google.maps.Geocoder();
var event = google.maps.event.addListener;
// intializing and creating the map.
var mapOptions = {
zoom: 4,
center: new google.maps.LatLng(-25.363882, 131.044922),
mapTypeId: google.maps.MapTypeId.TERRAIN
};
var map = new google.maps.Map(document.getElementById('map'),
mapOptions);
event(map,'click',function(e){
var marker = placeMarker_and_attachMessage(e.latLng,map,count);
count = count + 1;
});
} // end of initalize.
function placeMarker_and_attachMessage(position,map)
{
var event = google.maps.event.addListener;
var message = ['This', 'is', 'the', 'secret', 'message'];
var marker = new google.maps.Marker({
position: position,
map: map
});
var pos = info_text(position);
alert('pos is: ' + pos);
var infowindow = new google.maps.InfoWindow({
content: 'hello'
});
event(marker,'mouseover',function(){
infowindow.open(map,this);
});
event(marker,'mouseout',function(){
infowindow.close();
});
} // end of function.
function info_text(position)
{
var lat = parseFloat(position.lat());
var lng = parseFloat(position.lng());
alert('lat,lng is: ' + (lat,lng));
var latlng = new google.maps.LatLng(lat,lng);
alert('just before geocode');
geocoder.geocode({'latLng': latlng}, function(results, status)
{
if (status == google.maps.GeocoderStatus.OK)
{
alert('in info_text If statement');
if(results[1])
{
alert('in inner if statement');
var finalResult = myCallback(results[1].formatted_address);
return finalResult;
}
else
{
alert('no results found');
}
}
else
{
alert('could not pinpoint location');
}
});
}
function myCallback(loc)
{
alert('i have a location!');
return loc;
}
google.maps.event.addDomListener(window, 'load', initialize);

Your function info_text doesn't return anything, so this line:
var pos = info_text(position);
is where pos is undefined.
You need to include:
return something;
at some point in your function (like you have done further down).
Added
Your function myCallback returns a value, but where it is used:
myCallback(results[1].formatted_address);
it doesn't store the return-value anywhere - it is just discarded.

Related

chrome doesnt show google map - javascript

My code works fine in firefox but not word in chrome(chrome doesn't show google map):
http://www.khadamatchi.com/frontend/Index/addAddressByUser
my codes:
getLocation();
function getLocation() {
if (navigator.geolocation) {
navigator.geolocation.getCurrentPosition(showPosition);
} else {
alert("Geolocation is not supported by this browser.");
}
}
function showPosition(position) {
var lat = position.coords.latitude;
var lng = position.coords.longitude;
getAddress(lat,lng);
initialize(lat,lng);
}
//START FIND LOCATION
var geocoder = new google.maps.Geocoder();
var marker = null;
var map = null;
function initialize(lat,lng) {
//var $latitude = document.getElementById('latitude');
// var $longitude = document.getElementById('longitude');
var latitude = lat;
var longitude = lng;
var zoom = 16;
var LatLng = new google.maps.LatLng(latitude, longitude);
var mapOptions = {
zoom: zoom,
center: LatLng,
panControl: false,
zoomControl: false,
scaleControl: true,
mapTypeId: google.maps.MapTypeId.ROADMAP
}
map = new google.maps.Map(document.getElementById('googleMap'), mapOptions);
if (marker && marker.getMap) marker.setMap(map);
marker = new google.maps.Marker({
position: LatLng,
map: map,
title: 'Drag Me!',
draggable: true
});
google.maps.event.addListener(marker, 'dragend', function(marker) {
var latLng = marker.latLng;
// $latitude.value = latLng.lat();
// $longitude.value = latLng.lng();
//console.log( );
getAddress(latLng.lat(),latLng.lng());
});
}
// initialize();
$('#findbutton').click(function (e) {
var address = $("#Postcode").val();
geocoder.geocode({ 'address': address }, function (results, status) {
if (status == google.maps.GeocoderStatus.OK) {
map.setCenter(results[0].geometry.location);
marker.setPosition(results[0].geometry.location);
$(latitude).val(marker.getPosition().lat());
$(longitude).val(marker.getPosition().lng());
} else {
alert("Geocode was not successful for the following reason: " + status);
}
});
e.preventDefault();
});
function getAddress(lat,lon)
{
//http://maps.googleapis.com/maps/api/geocode/json?latlng=35.706172,51.316568&sensor=true&language=fa
$.ajax({
url: "http://maps.googleapis.com/maps/api/geocode/json?latlng=" + lat +","+lon + "&sensor=true&language=fa",
success: function(response) {
//Do Something
console.log(response);
var address_components = response.results[0].formatted_address;
$('#address').val(address_components);
},
error: function(xhr) {
//Do Something to handle error
}
});
}
You have two errors here, you are trying to execute some jQuery related code before you download jQuery, resulting in error;
Uncaught ReferenceError: $ is not defined
Example on line 172 $(document).ready(function
Also you are trying to execute some code to the google maps before it is loaded, row 632 var geocoder = new google.maps.Geocoder();
Resulting in error Uncaught ReferenceError: google is not defined
You can move the geocoder inside the initalize function you have or remove the async defer from the <script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyCfbbmUkl56UuSeZ5nSOwsKTNxplmnheuU&callback=initialize&language=fa" async defer></script>
You also define function initialize twice in the source code, this might bring you some weird issues in the future, each function name should be unique and descriptive about what they do.
UPDATE
For the comment, as you removed the async defer from the google maps loading, can you also remove the &callback=initialize from the src url.
UPDATE 2
Now we've gotten rid of the errors, now there is something weird going on in the function initialize
function initialize()
{
var tehran=new google.maps.LatLng(35.6961111,51.4230556);
var mapProp = {
center:tehran,
zoom:13,
mapTypeId:google.maps.MapTypeId.ROADMAP
};
var map = new google.maps.Map(document.getElementById("googleMap"),mapProp);
var myCity = new google.maps.Circle({
center:tehran,
radius:3000,
strokeColor:"#0000FF",
strokeOpacity:0.8,
strokeWeight:2,
fillColor:"#0000FF",
fillOpacity:0.4
});
myCity.setMap(map);
}
This does not work, if you replace this with;
function initMap()
{
map = new google.maps.Map(document.getElementById('googleMap'), {
center: {lat: 35.6961111, lng: 51.4230556},
zoom: 13
});
}
initMap();
The map will display correctly, then you can later focus on customising the styles of the map.

Geolocation with Google maps API and Google text Search

I am new to javascript converting from VB. This is my first shot at creating a dynamic google map and am ultimatly trying to generate a google map using the users location and apply a places search for sports stores. Currently my map generates and zooms to my location but does not apply the search results with markers.
here is my code:
<script type="text/javascript" src="https://maps.googleapis.com/maps/api/js?libraries=places"></script>
<article>
<p>Finding your location: <span id="status">checking...</span></p>
</article>
<script>
function success(position) {
var s = document.querySelector('#status');
if (s.className == 'success') {
// not sure why we're hitting this twice in FF, I think it's to do with a cached result coming back
return;
}
s.innerHTML = "found you!";
s.className = 'success';
var mapcanvas = document.createElement('div');
mapcanvas.id = 'mapcanvas';
mapcanvas.style.height = '400px';
mapcanvas.style.width = '560px';
document.querySelector('article').appendChild(mapcanvas);
var latlng = new google.maps.LatLng(position.coords.latitude, position.coords.longitude);
var myOptions = {
zoom: 10,
center: latlng,
mapTypeControl: false,
navigationControlOptions: {style: google.maps.NavigationControlStyle.SMALL},
mapTypeId: google.maps.MapTypeId.ROADMAP
};
map = new google.maps.Map(document.getElementById("mapcanvas"), myOptions);
var service;
var infowindow;
var request = {
location: latlng,
radius: '3200',
query: 'sports'
};
service = new google.maps.places.PlacesService(map);
service.textSearch(request, callback);
function callback(results, status) {
if (status == google.maps.places.PlacesServiceStatus.OK) {
for (var i = 0; i < results.length; i++) {
var place = results[i];
createMarker(results[i]);
}
}
}
}
function error(msg) {
var s = document.querySelector('#status');
s.innerHTML = typeof msg == 'string' ? msg : "failed";
s.className = 'fail';
// console.log(arguments);
}
if (navigator.geolocation) {
navigator.geolocation.getCurrentPosition(success, error);
} else {
error('not supported');
}
</script>
I feel like I might be missing some var assignments or not over writing the current map from "map canvas". Has any one created something similar that provide some insight? Any help is greatly appreciated to find why my search results will not display on the map. Thanks!
Your code works but you are missing the createMarker function. This is not an API method.
Uncaught ReferenceError: createMarker is not defined
An example createMarker function:
function createMarker(place) {
new google.maps.Marker({
position: place.geometry.location,
map: map
});
}
Note: if you only need the location in that function you could also call it and modify it this way:
function callback(results, status) {
if (status == google.maps.places.PlacesServiceStatus.OK) {
for (var i = 0; i < results.length; i++) {
var place = results[i];
console.log(place);
createMarker(results[i].geometry.location); // pass only the location to createMarker
}
}
}
function createMarker(position) {
new google.maps.Marker({
position: position,
map: map
});
}
JSFiddle demo

using google map geocoder.geocode before initializing the map

I have created a nice Google map form that gets clients data from the database ( with a jQuery post call to php) and loads it into the clients_details. if clients_details[]['location'] which is Latlng is provided in the database all works well and marker gets displayed as expected. Problem is that when clients_details[]['location'] is not provided then I use the address from clients_details[]['address'] and try to get position of the marker by using geocoder.geocode. However surprisingly every time the code gets to the geocoder it jumps from it and comes back to it after it initialized the map ! so markers wont get added to the map !
I am assuming it has something to do with JavaScript function priorities but not sure how
<script>
var clients_details // getting this from database;
var infowindow =[];
var geocoder;
var map;
function showMarkers(clients_details)
{
var marker = [];
for (var i = 0; i < clients_details.length; i++)
{
content = 'Test Content' ;
infowindow[i] = new google.maps.InfoWindow({
content: content,
maxWidth: 350
});
var client_location;
if (clients_details[i]['location'] !== null)
{
// Geting Lat and Lng from the database string
LatLng = clients_details[i]['location'];
client_location = new google.maps.LatLng (LatLng);
}
else
{
client_address = clients_details[i]['address'];
geocoder.geocode(
{ 'address': client_address},
function(results, status)
{
if (status == google.maps.GeocoderStatus.OK)
{
client_location = results[0].geometry.location;
}
else
alert('Geocode was not successful for the following\n\
reason: ' + clients_details[i]['name']+'\n' + status);
});
}
marker[i] = new google.maps.Marker({
position: client_location,
map: map,
title: clients_details[i]['name']
});
// Add 'click' event listener to the marker
addListenerMarkerList(infowindow[i], map, marker[i]);
}// for
}// function
The
marker[i] = new google.maps.Marker({
position: client_location,
map: map,
title: clients_details[i]['name']
});
Code should be inside the callback in the geocoder.geocode call.
Because in your code the client_location is computed after the marker[i].
What you could do is:
compute the client_location and when the client_locolation is computed
then compute the marker[i]
So your code could be like this:
// ... your code as is
geocoder.geocode(
{ 'address': client_address},
function(results, status)
{
if (status == google.maps.GeocoderStatus.OK)
{
client_location = results[0].geometry.location;
// closure needed, for the marker[i] to work correctly,
// because we are in a loop on i
(function (i) {
marker[i] = new google.maps.Marker({
position: client_location,
map: map,
title: clients_details[i]['name']
});
})(i);
}
else
{
alert('Geocode was not successful for the following\n\
reason: ' + clients_details[i]['name']+'\n' + status);
}
}
);
// .... your code as is
You need to bind your call back function to the right event. Bind the initialize of the map to window load. Inside that function then call the rest of the marker/geocoder logic. As extracted from their documentation:
function initialize() {
var mapOptions = {
zoom: 4,
center: new google.maps.LatLng(-25.363882, 131.044922)
};
var map = new google.maps.Map(document.getElementById('map-canvas'),
mapOptions);
var marker = new google.maps.Marker({
position: map.getCenter(),
map: map,
title: 'Click to zoom'
});
google.maps.event.addListener(map, 'center_changed', function() {
// 3 seconds after the center of the map has changed, pan back to the
// marker.
window.setTimeout(function() {
map.panTo(marker.getPosition());
}, 3000);
});
google.maps.event.addListener(marker, 'click', function() {
map.setZoom(8);
map.setCenter(marker.getPosition());
});
}
google.maps.event.addDomListener(window, 'load', initialize);

Google Maps Places API

I'm a Javascript newbie and I can't seem to get this script working.
Managed to get the geolocation working but no places markers show when loaded.
Tried a lot of stuff can you guys help me out?
var map;
function initialize() {
var mapOptions = {
mapTypeId: google.maps.MapTypeId.ROADMAP,
zoom: 13
};
map = new google.maps.Map(document.getElementById('map-canvas'),
mapOptions);
var input = document.getElementById('searchtxt');
var autocomplete = new google.maps.places.Autocomplete(input);
autocomplete.bindTo('bounds', map);
if(navigator.geolocation) {
navigator.geolocation.getCurrentPosition(function(position) {
var pos = new google.maps.LatLng(position.coords.latitude,
position.coords.longitude);
map.setCenter(pos);
}, function() {
handleNoGeolocation(true);
});
} else {
// Browser doesn't support Geolocation
handleNoGeolocation(false);
}
var request = {
location: pos,
radius: 1500,
types: ['restaurant']
};
alert('OK -> ' + request); //THIS DOESN'T SHOW. WHY??
var service = new google.maps.places.PlacesService(map);
service.nearbySearch(request, callback);
}
function handleNoGeolocation(errorFlag) {
if (errorFlag) {
var content = 'Error: The Geolocation service failed.';
} else {
var content = 'Error: Your browser doesn\'t support geolocation.';
}
var options = {
map: map,
position: new google.maps.LatLng(60, 105),
content: content
};
map.setCenter(options.position);
}
function callback(results, status) {
if (status == google.maps.places.PlacesServiceStatus.OK) {
for (var i = 0; i < results.length; i++) {
createMarker(results[i]);
}
} else {
}
}
function createMarker(place) {
var placeLoc = place.geometry.location;
var marker = new google.maps.Marker({
map: map,
position: place.geometry.location
});
google.maps.event.addListener(marker, 'click', function() {
infowindow.setContent(place.name);
infowindow.open(map, this);
});
}
google.maps.event.addDomListener(window, 'load', initialize);
Even the ALERT doesn't show, but if I put it before the var request statement it does show: "OK -> Undefined".
What's wrong?
Thanks.
getCurrentPosition() gets fired asynchronously. This means that the var pos variable isn't set in this scope. This leaves pos undefined. This throws an error when you attempt to set it in the var options object. This breaks the code and the alert() is never fired.
The alert() works before the object because the erroneous assignment, location: pos, hasn't happened yet.
This error was clearly displayed in the console so I would suggest learning to debug that way.
Here is a question that I asked a'while back that might help you:
how to use/store JSON data after the callback has fired?

How do I use Google Maps geocoder.getLatLng() and store its result in a database?

Hey everybody! Im trying to use getLatLng() to geocode a list of postal/zip codes and store the generated point in the database to be placed on a map later. This is what I've got so far:
$(".geocodethis").click(function () {
var geocoder = new GClientGeocoder();
var postalCode = $(this).siblings(".postal").val();
var id = $(this).siblings(".id").val();
geocoder.getLatLng(postalCode, function (point) {
if (!point) {
alert(postalCode + " not found");
} else {
alert(point);
var serializedPoint = $.param(point);
//Geocode(id, point);
}
});
});
function Geocode(id, point) {
alert(point);
$.post("/Demographic/Geocode/" + id, point, function () {
alert("success?");
});
}
but I'm getting this.lat is not a function in my error console when i try to serialize the point object or use it in $.post()
From my research, I understand that geocoder.getLatLng() is asynchronous, how would that affect what I'm trying to do? I'm not running this code in a loop, and I'm trying to post the point using the anonymous callback function.
How can I save the information from point to use later?
Update
Creating a marker and trying to post that still results in the this.lat is not a function in the error console.
$(".geocodethis").click(function () {
var geocoder = new GClientGeocoder();
var postalCode = $(this).siblings(".postal").val();
var id = $(this).siblings(".id").val();
geocoder.getLatLng(postalCode, function (point) {
if (!point) {
alert(postalCode + " not found");
} else {
alert(point);
var marker = new GMarker(point);
$.post("/Demographic/Geocode/" + id, marker, function () {
alert("success?");
});
}
});
});
** Another Update **
I really need to save the geocoded address for later, even if I store the latitude/longitude values in my database and remake the marker when I'm ready to put it onto a map. Again, serializing or posting - seemingly using the point in any way other than in google maps functions gives the this.lat is not a function exception in my error log.
I'm using asp.net mvc - are there any frameworks out there that would make this easier? I really need help with this. Thanks.
If your stuck for 2 days maybe a fresh v3 start would be a good thing, this snipped does a similair job for me...
function GetLocation(address) {
var geocoder = new google.maps.Geocoder();
geocoder.geocode({ 'address': address }, function (results, status) {
if (status == google.maps.GeocoderStatus.OK) {
ParseLocation(results[0].geometry.location);
}
else
alert('error: ' + status);
});
}
}
function ParseLocation(location) {
var lat = location.lat().toString().substr(0, 12);
var lng = location.lng().toString().substr(0, 12);
//use $.get to save the lat lng in the database
$.get('MatchLatLang.ashx?action=setlatlong&lat=' + lat + '&lng=' + lng,
function (data) {
// fill textboss (feedback purposes only)
//with the found and saved lat lng values
$('#tbxlat').val(lat);
$('#tbxlng').val(lng);
$('#spnstatus').text(data);
});
}
Have you tried this?
$(".geocodethis").click(function () {
var geocoder = new GClientGeocoder();
var postalCode = $(this).siblings(".postal").val();
var id = $(this).siblings(".id").val();
geocoder.getLatLng(postalCode, function (point) {
if (!point) {
alert(postalCode + " not found");
} else {
alert(point);
var marker = new GMarker(point);
map.addOverlay(marker);
obj = {lat: marker.position.lat(),
lng: marker.position.lng()};
$.post("/Demographic/Geocode/" + id, obj, function () {
alert("success?");
});
}
});
});
I haven't used V2 in a long time, so I'm not sure about the exact syntax, but the point is to create an object from the information you need (lat/lng) and serialize that.
Also, an upgrade to V3 is much recommended, if plausible.
You need to set a marker on the map, which takes a lat/long. You can save that info however you want or display immediately. (Code truncated for demo purpose)
map = new google.maps.Map(document.getElementById("Map"), myOptions);
geocoder.geocode({ 'address': address }, function (results, status) {
if (status == google.maps.GeocoderStatus.OK) {
var marker = new google.maps.Marker({
position: results[0].geometry.location
});
marker.setMap(map);
}
}
UPDATE (FOR v2)
$(".geocodethis").click(function () {
var geocoder = new GClientGeocoder();
var postalCode = $(this).siblings(".postal").val();
var id = $(this).siblings(".id").val();
geocoder.getLatLng(postalCode, function (point) {
if (!point) {
alert(postalCode + " not found");
} else {
map.setCenter(point, 13);
var marker = new GMarker(point);
map.addOverlay(marker);
}
});
});
In V3 the coordinates must be first serialized as a string as shown by Arnoldiuss, before sending as json post data.
var lat = latlong.lat().toString().substr(0, 12);
var lng = latlong.lng().toString().substr(0, 12);
<html>
<head>
<meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
<%# taglib prefix="s" uri="/struts-tags"%>
<script type="text/javascript" src="http://maps.google.com/maps/api/js?key=AIzaSyDS1d1116agOa2pD9gpCuvRDgqMcCYcNa8&sensor=false"></script>
<script type="text/javascript">
function initialize() {
var latitude = document.getElementById("latitude").value;
latitude = latitude.split(",");
var longitude = document.getElementById("longitude").value;
longitude = longitude.split(",");
var locName = document.getElementById("locName").value;
locName = locName.split(",");
var RoadPathCoordinates = new Array();
RoadPathCoordinates.length = locName.length;
var locations = new Array();
locations.length = locName.length;
var infowindow = new google.maps.InfoWindow();
var marker, i;
var myLatLng = new google.maps.LatLng(22.727622,75.895719);
var mapOptions = {
zoom : 16,
center : myLatLng,
mapTypeId : google.maps.MapTypeId.ROADMAP
};
var map = new google.maps.Map(document.getElementById("map_canvas"), mapOptions);
//To Draw a line
for (i = 0; i < RoadPathCoordinates.length; i++)
RoadPathCoordinates[i] = new google.maps.LatLng(latitude[i],longitude[i]);
var RoadPath = new google.maps.Polyline({
path : RoadPathCoordinates,
strokeColor : "#FF0000",
strokeOpacity : 1.0,
strokeWeight : 2
});
//Adding Marker to given points
for (i = 0; i < locations.length; i++)
locations[i] = [locName[i],latitude[i],longitude[i],i+1];
for (i = 0; i < locations.length; i++)
{marker = new google.maps.Marker({
position : new google.maps.LatLng(locations[i][1], locations[i][2]),
map : map
});
//Adding click event to show Popup Menu
var LocAddress ="";
google.maps.event.addListener(marker, 'click', (function(marker, i)
{ return function()
{
GetAddresss(i);
//infowindow.setContent(locations[i][0]);
infowindow.setContent(LocAddress);
infowindow.open(map, marker);
}
})(marker, i));}
function GetAddresss(MarkerPos){
var geocoder = null;
var latlng;
latlng = new google.maps.LatLng(latitude[MarkerPos],longitude[MarkerPos]);
LocAddress = "91, BAIKUNTHDHAAM"; //Intializing just to test
//geocoder = new GClientGeocoder(); //not working
geocoder = new google.maps.Geocoder();
geocoder.getLocations(latlng,function ()
{
alert(LocAddress);
if (!response || response.Status.code != 200) {
alert("Status Code:" + response.Status.code);
} else
{
place = response.Placemark[0];
LocAddress = place.address;
}
});
}
//Setting up path
RoadPath.setMap(map);
}
</script>
</head>
<body onload="initialize()">
<s:form action="mapCls" namespace="/">
<s:hidden key="latitude" id="latitude"/>
<s:hidden key="longitude" id="longitude"/>
<s:hidden key="locName" id="locName"/>
<div id="map_canvas" style="float:left;width:70%;height:100%"></div>
</s:form>
</body>
</html>
I am doing reverse Geocoding, and want address of marker using lat and longitude. M facing problem with function "GetAddresss()", line "geocoder.getLocations(latlng,function ()" is not working properly. what should I Do?

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