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Create Element to insert an API

I want to create a div using javascript to put my google map into.
It creates a div, but doesnt put the map api into it. Please help.

You need to make sure the Google Maps API script has loaded before running your code. Currently, you are trying to build the map before the browser has downloaded the map API.
The simplest way to fix this is to change your HTML to this:
<script src="https://maps.googleapis.com/maps/api/js?key="Entered key here deleted it for stackoverflow"&callback=initMap">
<script src="javascript.js"></script>
You could also remove the Google Maps script tag and load it dynamically in javascript.js using jQuery’s $.getScript() or with plain JS using https://github.com/filamentgroup/loadJS, running your code as the callback.

initMap is firing when the script loads, but create isn't getting called until you click that p tag. Here's a way to get around that issue, but still wait for the script to load before allowing clicks:
var mapready = false, createcalled = false;
function create()
{
createcalled = true;
if(mapready){
var newDiv = document.createElement("map");
newDiv.id = "map";
newDiv.style.border="solid";
document.body.appendChild(newDiv);
var uluru = {lat: 54.278556, lng: -8.460095};
var map = new google.maps.Map(document.getElementById('map'), {zoom: 16,center: uluru});
var marker = new google.maps.Marker({position: uluru,map: map});
}
}
function initMap()
{
mapready = true;
if(createcalled) create();
}
In this scenario, if the user clicks the p tag before the map is ready, the create function will fire as soon as the map API finishes loading.

GoogleMaps InfoWindow appear at a corner

here is my code in html to generate marker and infowindow(with ruby on rails)
var marker=[]
function initMap() {
var latLng1 = new google.maps.LatLng(1.352083, 103.819836);
var myOptions = {
zoom: 12,
center: latLng1,
mapTypeId: google.maps.MapTypeId.ROADMAP
}
map = new google.maps.Map(document.getElementById('map_canvas'), myOptions);
for(i=0;i<gon.astatic.length;i++){
var latLng = new google.maps.LatLng(gon.astatic[i][1], gon.astatic[i][2]);
if(i<2){
marker[i] = new MarkerWithLabel({position: latLng, map: map,icon:"/assets/green_MarkerV.png" ,labelClass: "labels",labelContent: gon.astatic[i][3]});}
else
{
marker[i] = new MarkerWithLabel({position: latLng, map: map,icon:"/assets/green_MarkerN.png" ,labelClass: "labels",labelContent: gon.astatic[i][3]});
}
var iw =new google.maps.InfoWindow({content: 'HI' });
google.maps.event.addListener(marker[i],"mouseover",function(e){iw.open(map,marker[i]);})
}
this gon is just some 'stupid' method I use to pass data from ruby on rails controller to javascript.
for all marker,the infowindow all appear at corner.
But for my another map(which have only one marker with infowindow)it works fine.
What might be my problem?why this infowindow appear in wrong position?Instead of just above the marker?
EDIT:
After half day's trouble shoot,I feel the problem is at
google.maps.event.addListener(marker[i],"mouseover",function(e){iw.open(map,marker[i]);})
when the listener calls back,the value inside marker is i ,which is not a actual number,so the marker display at a corner.I feel the problem is can't pass variable into addListener,can only put in actual number.How to solve this?

Each instance of the function declared inside the for loop shares the same closure containing the value i, and so all of your addListener calls are essentially calling iw.open(map, undefined) since i will be off the end of the array at the end of the iteration.
See JavaScript closure inside loops – simple practical example for sample solutions to this problem, and How do JavaScript closures work for more information about closures in JavaScript in general.

The problem is with your MarkerWithLabel library. Infowindow take position from marker. Try use this link http://google-maps-utility-library-v3.googlecode.com/svn/tags/markerwithlabel/1.1.8/docs/examples.html . It has all the things that you want to implement. It it's not work then you can also set position for infowindow with setPosition() function just pass latlng that you used to create marker and you are done.

i dont recommend using new gem just to pass data from ruby to js...you can do this simply by many ways...your code seems good but i cannot say how gon is handling your js script.Please take a look at this similar question where i have implemented the same dynamic map with dynamic markers and infowindows.This code is working great
see here

Load a map with specific places acount as a reference without iframe?

Is there a way to load a map using js, but show the reference location as an actual places listing?
I'd like to load a map that shows a particular business (I have the places reference number) then display a map around it.
I would just use the iframe, but it doesn't allow for the level of customization that the js library does.

Yes. That is one of the more standard ways of using maps.
You have the lat long for the location to both center your map and drop a marker (probably a custom image of for instance the company logo).
Just follow any of the tutorials. They all show how to do this.

If you want to display a business that you have the reference number for then use the PlacesService.
You will also need to include the places library in the API url.
e.g
// I assume the map is already loaded and defined as variable called map
var placesService = new PlacesService();
placesService.getDetails({reference: placeReferenceNumber}, function(place, status) {
if (status === google.maps.places.PlacesServiceStatus.OK) {
var marker = new google.maps.Marker({
map: map,
position: place.geometry.location
});
// Warning: Viewport may not always be defined
map.setBounds(place.geometry.viewport);
}
});

Javascript argument parameters and google maps

I'm introducing myself to Google Maps API, and to JavaScript as well.
I already have set my map on my website, and now I'm trying to dynamically set multiple markers on the same map.
For that, I wrote this function:
function teste(lat,long){
alert (lat);
alert (long);
//var companyPos3 = new google.maps.LatLng(41.545308,-8.421782);
var companyPos3 = new google.maps.LatLng(lat,long);
var companyMarker3 = new google.maps.Marker({
position: companyPos3,
map: map,
// icon: companyLogo,
title:"Mar!!!" });
//}
...
}
And my problem resides right here. I can't set the google.maps.LatLng with 'lat' and 'long' function parameters. However, the alert dialog messages pop up, showing the values that are from PHP.
I tried also to remove the alert function but the marker didn't show as well.
I'm not sure if it there is a Google Maps API trick, or JavaScript trick.
Oh, and if I set the values as the commented line, it works, but I don't want this solution :).

long is the reserved word in JS. Please check here. So, please try lng instead of long also for setting icon please see here. Try something like
function teste(lat,lng){
alert (lat);
alert (lng);
//var companyPos3 = new google.maps.LatLng(41.545308,-8.421782);
var companyPos3 = new google.maps.LatLng(lat,lng);
var companyMarker3 = new google.maps.Marker({
position: companyPos3,
map: map,
// icon: companyLogo,
title:"Mar!!!" });
//}
...
}

Google map error: a is null

I have a program that I want to use google maps for. The problem is I get an error that says a is null where a is a var used in the google map api. Here is how I call my google map:
//Creates a new center location for the google map
var latlng = new google.maps.LatLng(centerLatitude, centerLongitude);
//The options for the google map
var myOptions = {
zoom: 7,
maxZoom: 12,
center: latlng,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
//Creates the new map
var map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);
And here is what my HTML tag looks like:
<div id = "map_canvas"></div>
I get the lat and lng on page load through the url. These values are passed in correctly so I know that is not the problem. I think that it has to do with the var map = new google.maps.Map(document.getElementById("map_canvas"), myOptions); not being correct. Any suggestions?
EDIT: Here is the error message:
a is null
fromLatLngToPoint(a=null)
yg(a=null, b=Object { zoom=7, maxZoom=12, more...})
d(d=Document Default.aspx?lat=30.346317&lng=105.46313, f=[function()])
d(a=undefined)
d()
[Break On This Error] function Qf(a){a=a.f[9];return a!=i?a:...);function sg(a){a[ic]&&a[ic]Vb}

Make sure you specify the size of the element that holds the map. For example:
<div id="map_canvas" style="width: 500px; height: 500px;"></div>
Also make sure your map variable is defined in the global scope and that
you initialize the map once the DOM is loaded.

You are probably not listening for the onload event that fires when the page is completely loaded. As a result, your script is running but the div you are creating doesn't yet exist. Use jQuery to listen for this event, like so:
$(document).ready(function () {
map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);
});
If you don't want to use jQuery, then add an event listener to body.onload

This rather cryptic error means that the script can't find the map div.
This could happen for a couple of reasons.
1. You're using the wrong ID to refer to the map.
Check your ids (or classes) and make sure the element you're referring to actually exists.
2. You're executing the script before the DOM is ready.
Here's a jQuery example. Notice we're triggering initialise on document ready, not onDOMReady. I've taken the liberty of wrapping the script in a closure.
(function($) {
function initialize() {
var mapOptions = {
center: new google.maps.LatLng(-34.397, 150.644),
zoom: 8,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
var map = new google.maps.Map(document.getElementById("map"),
mapOptions);
}
$(document).ready(initialize);
})(jQuery)
You could also use:
google.maps.event.addDomListener(window, 'load', initialize);
if you prefer a Google solution.

Had the exact same problem and this is have i fixed it for me.
The thing was that I had 2 google maps in my website - one in the footer and the other one on the contact page, but i called them both in one JS file like so:
var map1 = new google.maps.Map(document.getElementById("map-canvas-footer"), settings1);
var map2 = new google.maps.Map(document.getElementById("map-canvas"), settings2);
But the thing is that the object with id="map-canvas" was located only on the contact page.
So at first you have to check if that element exists on the page like so:
if ($("#map-canvas-footer").length > 0){
var map1 = new google.maps.Map(document.getElementById("map-canvas-footer"), settings1);
}
if ($("#map-canvas").length > 0){
var map2 = new google.maps.Map(document.getElementById("map-canvas"), settings2);
}
I hope this can help someone else as well ;)

This happens when the map is not yet loaded. You should build your map when the Maps API JavaScript has loaded. Executing the function to initialize your map only when the API has fully loaded passing it to the "callback" parameter in the Maps API bootstrap.
function initialize() {
var mapOptions = {
zoom: 8,
center: new google.maps.LatLng(-34.397, 150.644),
mapTypeId: google.maps.MapTypeId.ROADMAP
}
var map = new google.maps.Map(document.getElementById("map_canvas"), mapOptions);
}
function loadScript() {
var script = document.createElement("script");
script.type = "text/javascript";
script.src = "http://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&sensor=TRUE_OR_FALSE&callback=initialize";
document.body.appendChild(script);
}
window.onload = loadScript;
This is actually in the Maps API Docs here. Hope this helps!

Make sure that your canvas div (Div associated with the map) exists.
Sometimes, if we rename the div's id attribute.
Then it creates problem as it does not get the canvas div.

I got this error once. Make sure the map script runs only on pages using the map. You can check if the map exists by using an "if". Something like this:
if ($('mapClass').length>0) { // here you run the google maps functions }
See ya

Solved, the google map type a error, make sure you get object var map = document.getElementById('map-canvas') returning properly using alert(map). Check the div container id name same as specified in getElementByid.
I have also stuck with the same type a error, fixed it by checking getElementByid('map-canvas'). Sample code enter link description here

I have fixed it removing my "style" property from the "div" tag an declaring it correctly, in a css file

My response is bit old but for those who still come here for reference, I have a similar solution. I put map initialization code as specified here https://developers.google.com/maps/documentation/javascript/adding-a-google-map
inside jQuery document ready function. Below is the code that worked in my case:
$(document).ready(function () {
var uluru = {lat: -25.344, lng: 131.036};
var map = new google.maps.Map( document.getElementById('embedmap'), {zoom: 14, center: uluru} );
var marker = new google.maps.Marker({position: uluru, map: map});
});