Develop Reference

Google Maps API v3 Markers only load sometimes

I have a map-making tool that is built with the Google Maps API V3. It allows users to enter two or more locations and produce a map and route. I also have a checkbox that, when clicked, shows markers indicating nearby points of interest.
When I first built the tool, I think it worked well every time. Recently, though, I've noticed that the markers do not always appear when the checkbox is clicked. The map and routing work fine, but the markers only work occasionally. This error seems to occur when they don't work:
Uncaught ReferenceError: map is not defined
It references a section of the "cmarkers" section of javascript (see below).
Background detail: This is part of a Rails web app and a webpage / layout called "Itineraries". When you land on the itineraries webpage and click on the "Map Maker" icon, the map-making tool appears. It's loaded in an i-frame, it's called "map.html.erb", and the map view lives in /views/itineraries. All of the javascript for the map maker lives in the Itineraries layout file, however.
Based on reviewing these posts, I think it might be something in the way that I've ordered or initialized the code, and I think the main culprit is likely in that "cmarkers" section of the code.
Google Maps API Sometimes Not Showing Markers
Google maps api(v3) doesn't show markers
Google Maps API v3 javascript Markers don't always load
I've tried several different changes, but each has either not worked or stopped the map from initializing. Here is the javascript; please note that the API key and other small sections are redacted. Below it is the code for the markers.
<script src="https://maps.googleapis.com/maps/api/js?key=MYAPIKEY&sensor=false"></script>
<script type='text/javascript'>
$(function(){
var directionsDisplay;
var map;
function overlaysClear() {
if (markersArray) {
for( var i = 0, n = markersArray.length; i < n; ++i ) {
markersArray[i].setVisible(false);
}
}
}
function overlaysShow() {
if (markersArray) {
for( var i = 0, n = markersArray.length; i < n; ++i ) {
markersArray[i].setVisible(true);
}
}
}
$("#showmapview").click(function() {
overlaysClear();
$('#mapeach').attr('checked', false);
});
$('#mapeach').change(function() {
if( $('#mapeach').attr("checked")) {
overlaysShow();
}
else {
overlaysClear();
}
});
cmarkers();
google.maps.event.addDomListener(window, 'load', initialize);
});
var directionsService = new google.maps.DirectionsService();
var markersArray = [];
var arrInfoWindows = null;
function initialize() {
var rendererOptions = {
draggable: true,
panel:document.getElementById('directions_panel')
};
directionsDisplay = new google.maps.DirectionsRenderer(rendererOptions);
var chicago = new google.maps.LatLng(41.850033, -87.6500523);
var mapOptions = {
zoom: 6,
center: chicago,
mapTypeId: google.maps.MapTypeId.ROADMAP
}
map = new google.maps.Map(document.getElementById("map_canvas"), mapOptions);
directionsDisplay.setMap(map);
}
function calcRoute() {
var start = document.getElementById("start").value;
var end = document.getElementById("end").value;
var waypts = [];
var checkboxArray = document.getElementById("waypoints");
for (var i = 0; i < checkboxArray.length; i++) {
waypts.push({
location:checkboxArray[i].value,
stopover:true
});
}
var request = {
origin: start,
destination: end,
waypoints: waypts,
optimizeWaypoints: optimize,
travelMode: google.maps.TravelMode.DRIVING
};
directionsService.route(request, function(response, status) {
if (status == google.maps.DirectionsStatus.OK) {
directionsDisplay.setDirections(response);
var route = response.routes[0];
}
});
};
function cmarkers() {
$.getJSON( "/mapeach.js", {}, function( data ) {
$.each( data, function( i, item ) {
var loc = item.mainlocation;
$("#markers").append('<li>' + loc.nickname + '</li>');
var marker = new google.maps.Marker({
position: new google.maps.LatLng(+loc.latitude, +loc.longitude),
map: map,
title: loc.nickname,
});
markersArray.push(marker);
var infowindow = new google.maps.InfoWindow({
content: '<a class="clink" href="/spots/'+ loc.id +'/'+ loc.nickname +'" target="_blank">'+ loc.nickname +'</a>'
});
google.maps.event.addListener(marker, 'click', function() {
if (arrInfoWindows != null) {
arrInfoWindows.close();
}
infowindow.open(map,marker);
arrInfoWindows = infowindow;
});
});
});
};
</script>
The mapeach.js file is formatted as below:
[{"mainlocation":{"latitude":"40.706352","nickname":"First Location","id":100000,"longitude":"-73.987650"}},{"mainlocation":{"latitude":"34.061148","nickname":"Second Location","id":100001,"longitude":"-118.273067"}}]

I was able to solve this problem by moving the cmarkers code inside the initialize. I think that the javascript wasn't making clear that the map variable in the initialize was also the map variable in the cmarkers function (sorry if the language isn't precise; I'm not great in js). See below:
function initialize() {
var rendererOptions = {
draggable: true,
panel:document.getElementById('directions_panel')
};
directionsDisplay = new google.maps.DirectionsRenderer(rendererOptions);
var chicago = new google.maps.LatLng(41.850033, -87.6500523);
var mapOptions = {
zoom: 6,
center: chicago,
mapTypeId: google.maps.MapTypeId.ROADMAP
}
map = new google.maps.Map(document.getElementById("map_canvas"), mapOptions);
directionsDisplay.setMap(map);
cmarkers();
function cmarkers() {
$.getJSON( "/mapeach.js", {}, function( data ) {
$.each( data, function( i, item ) {
var loc = item.mainlocation;
$("#markers").append('<li>' + loc.nickname + '</li>');
var marker = new google.maps.Marker({
position: new google.maps.LatLng(+loc.latitude, +loc.longitude),
map: map,
title: loc.nickname,
});
markersArray.push(marker);
var infowindow = new google.maps.InfoWindow({
content: '<a class="clink" href="/spots/'+ loc.id +'/'+ loc.nickname +'" target="_blank">'+ loc.nickname +'</a>'
});
google.maps.event.addListener(marker, 'click', function() {
if (arrInfoWindows != null) {
arrInfoWindows.close();
}
infowindow.open(map,marker);
arrInfoWindows = infowindow;
});
});
});
};
Special credit to this post for giving me the idea: can't see google marker

Show nearby Places in Google Maps in Meteor

I am trying to get nearby places like gym, atm on google maps. For this I have used dburles:google-maps package. I followed the instructions on Google Maps API and did the following. The map is generated, and the center marker is shown but I am not able to generate the places markers. Can anyone point out what I am doing wrong?
This is the JS code.
Template.map.helpers({
exampleMapOptions: function() {
// Make sure the maps API has loaded
if (GoogleMaps.loaded()) {
// Map initialization options
var data=Test.findOne().address.geopoint;
var lat=data[1];
var lng=data[0];
console.log([lat,lng]);
return {
center: new google.maps.LatLng(lat, lng),
zoom: 14
};
}
}
});
Template.map.onCreated(function() {
var self = this;
GoogleMaps.ready('exampleMap', function(map) {
var marker;
// Create and move the marker when latLng changes.
self.autorun(function() {
var data=Test.findOne().address.geopoint;
var lat=data[1];
var lng=data[0];
if (! lat && ! lng)
return;
// If the marker doesn't yet exist, create it.
if (! marker) {
marker = new google.maps.Marker({
position: new google.maps.LatLng(lat, lng),
map: map.instance
});
}
// The marker already exists, so we'll just change its position.
else {
marker.setPosition([lat,lng]);
}
// Center and zoom the map view onto the current position.
map.instance.setCenter(marker.getPosition());
map.instance.setZoom(14);
var pyrmont = new google.maps.LatLng(lat,lng);
// map = new google.maps.Map(document.getElementById('exampleMap'), {
// center: pyrmont,
// zoom: 15
// });
var request = {
location: pyrmont,
radius: '5000',
types: ['store']
};
service = new google.maps.places.PlacesService(map);
service.nearbySearch(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]);
}
}
}
});
});
});

Solved the issue by replacing map with map.instance in places search.

Google Places API not working with getCurrentPosition Geolocation in Ionic app

Trying to get Google Places API to notice my location and apply the functions below. Very new to this and not sure what I am doing wrong below as the API and all the functions works initially, but after I'm asked for my location, it shows where I am but nothing else works/aren't working together.
Cordova Geolocation plugin I added to my ionic app:
cordova plugin add https://git-wip-us.apache.org/repos/asf/cordova-plugin-geolocation.git
App.js
app.controller("MapController", function($scope, $ionicLoading) {
var map;
var infowindow;
var request;
var service;
var markers = [];
google.maps.event.addDomListener(window, 'load', function() {
var center = new google.maps.LatLng(42.3625441, -71.0864435);
var mapOptions = {
center:center,
zoom:16
};
map = new google.maps.Map(document.getElementById('map'), mapOptions);
navigator.geolocation.getCurrentPosition(function(pos) {
map.setCenter(new google.maps.LatLng(pos.coords.latitude, pos.coords.longitude));
var myLocation = new google.maps.Marker({
position: new google.maps.LatLng(pos.coords.latitude, pos.coords.longitude),
map: map,
title: "My Location"
});
});
$scope.map = map;
request = {
location: center,
radius: 1650,
types: ['bakery', 'bar']
};
infowindow = new google.maps.InfoWindow();
var service = new google.maps.places.PlacesService(map);
service.nearbySearch(request, callback);
function callback (results, status) {
if (status == google.maps.places.PlacesServiceStatus.OK) {
for (var i = 0; i < results.length; i++) {
createMarker(results[i]);
}
}
}
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);
});
}
});
});

When you get the position, you update the map's location, but you don't run a new Nearby Search.
So I think you want to call service.nearbySearch(...) in the getCurrentPosition callback.
You may also want to have your nearbySearch callback keep an array of the markers created via createMarker, so you can remove them when you run a new search (e.g. by calling marker.setMap(null) on each old marker).

How to show geolocated tweets on a map

I have been playing around with the twitter API getting random tweets or even geo tagged tweets and also with the google maps API. However I want to combine this two and try and show geo tagged tweets on a google map. Here is my code for getting the geo tagged Tweets which work fine.
var geo = (geo.coordinates[0], geo.coordinates[1])
//var geo = (34.052234, -118.243685)
client.get('search/tweets', { q:string.teamname, geocode: geo, count: 5},
function searchTweets(err, data, response) {
for(var index in data.statuses){
var tweet = data.statuses[index];
console.log(tweet.text);
console.log(tweet.geo.coordinates)
}
});
On a different file, I generated a map based on Longitude and Latitude, and I had the understanding that once I had retrieved the coordinates for the tweets, I could represent the tweets on a Google Map in the same way. However, my code is not working. My question is, how would I combine both pieces of code to generate a map which is marked with geo located Tweets?
function initialize() {
var myLatlng = new google.maps.LatLng(geo.coordinates[0], geo.coordinates[1]);
var mapOptions = {
center: myLatlng
zoom: 10,
}
var map = new google.maps.Map(document.getElementById("map-canvas"), mapOptions);
var marker = new google.maps.Marker({
position: myLatlng,
map: map,
title:"Tweet});
var infowindow = new google.maps.InfoWindow({
content: 'Geo tagged Tweet',
maxWidth:200 });
infowindow.open(map,marker);
google.maps.event.addListener(marker, 'click', function() {
infowindow.open(map, marker); });
}
google.maps.event.addDomListener(window, 'load', initialize);

I would do something like this (untested - I'm just writing down some thoughts).
1) You should strip down init so that it just contains the map set up. Ensure map is declared outside of the function, and include a call to the function that fetches your data using the lat/lng data.
var map;
function initialize() {
var lat = geo.coordinates[0];
var lng = geo.coordinates[1]
var myLatlng = new google.maps.LatLng(lat, lng);
var mapOptions = { center: myLatlng, zoom: 10 }
map = new google.maps.Map(document.getElementById("map-canvas"), mapOptions);
getData(lat, lng, processData);
}
2) You wrap your data fetching code in a new function declaration, which accepts lat/lng data, and a callback.
function getData(lat, lng, callback) {
client.get('search/tweets', { q:string.teamname, geocode: geo, count: 5},
function searchTweets(err, data, response) {
callback(data.statuses);
}
)
};
3) Process the tweet information. For each tweet create a marker (add the marker to an array of markers) and update the map
function processData(data) {
var markers = [];
for (var i = 0, l = data.length; i < l; i++) {
var marker = new google.maps.Marker({
id: i,
position: myLatlng(data[i].geo.coordinates[0], data[i].geo.coordinates[1),
map: map,
title: "Tweet"
});
markers.push(marker);
var infowindow = new google.maps.InfoWindow({
content: data[i].text,
maxWidth: 200
});
infowindow.open(map, marker);
google.maps.event.addListener(marker, 'click', function() {
infowindow.open(map, marker);
});
}
}

Infowindow on google map is not working

I am using google map api v3 with js and I am trying to to open infowndow on each marker on the map but through my code it is not opening here is my code sample please check it and tell me where is the error
<script type="text/javascript">
var map;
var markers = new Array();
function initialize() {
var map_center = new google.maps.LatLng(31.2330555556,72.3330555556);
var GPS = <%=GPS %>
var myOptions = {
zoom: 8,
scaleControl:true,
pancontrol: true,
streetViewControl: true,
center: map_center,
mapTypeControl: true,
mapTypeControlOptions: {
style: google.maps.MapTypeControlStyle.DROPDOWN_MENU
},
mapTypeId: google.maps.MapTypeId.HYBRID
}
map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);
var infowindow = new google.maps.InfoWindow();
for(i=0; i<GPS.length; i++)
{
var image = 'ico/no.png';
var ContentString = GPS[i].TITLE;
markers[i] = new google.maps.Marker(
{
position: GPS[i].GPS,
map: map,
draggable:true,
icon:image,
title:GPS[i].TITLE
});
google.maps.event.addListener(markers[i], 'click', function() {
infowindow.setContent(ContentString);
infowindow.open(map,markers[i]);
});
}
}
</script>

Try the following code:
google.maps.event.addListener(markers[i], 'click', function() {
infowindow.setContent(ContentString);
infowindow.open(map,this);
});

I have completed a program recently using the same api as yours. Facing to the same problem,I found the key factor is that the function of addlistener would work after the loop ended.It is said that the variable 'i' has reach to the maximizing value when the function of addlistener worked.So I have added a few steps to handle the problem. You can have a look at mine and I hope it is helpful for you.
function ShowParkingPoints() {
var adNum=document.getElementById("tableOne").rows.length;
var i;
var j;
var l;
var ly;
for (i=1;i<adNum;i++)
{
for(j=1;j<5;j++)
{
var k=i-1;
addArray[k]+=document.getElementById("tableOne").rows[i].cells[j].innerHTML;
}
}
for (i=0;i<adNum-1;i++){
var image = new sogou.maps.MarkerImage('images/flag.png',
new sogou.maps.Size(60, 60),
new sogou.maps.Point(0,0),
new sogou.maps.Point(0, 60));
var shape = {
coord: [1, 1, 1, 20, 18, 20, 18 , 1],
type: 'poly'
};
geocoder.geocode( { 'address': addArray[i]}, function(results, status) {
if (status == sogou.maps.GeocoderStatus.OK) {
var str=results[0].formatted_address;
//infowindow.setContent(str);
var marker1= new sogou.maps.Marker({
map: map,
icon: image,
shape: shape,
draggable:true,
position: results[0].geometry.location
});
i=i-1
markerArrayS[i]=marker1;
locationArray[i]=results[0].geometry.location;
sogou.maps.event.addListener(markerArrayS[i], 'click', function(event) {
makerClicked(event.latLng);
});
} else {
alert("Geocode was not successful for the following reason: " + status);
}
});
}
map.setCenter(mapCenter);
map.setZoom(13);
}

I think you just need to use 'i=i-1' to replace 'i' when you start to login event watcher.You can have a try. In a way,you need to notice that the order you storage in arrays when you want to read them out.