Google Maps API 3 – Markers
Google Maps API 3
Markers are the perfect way to put places of interest on a map and that’s probably one of the most used features in digital maps. In this article, which is the third in a series about Google Maps API 3, I will show you how to use them in Google Maps API 3.
If you aren’t already familiar with the map object, I recommend that you first read the two previous articles in this series.
The marker object
The marker object resides in the google.maps.Marker namespace and takes a single argument, options. Options is an object literal called Marker options that can have several properties of which two are required:
- map [Map]
Map is a reference to the map where you want to add the marker. - position [LatLng]
This property indicates the position of the marker and is of typegoogle.maps.LatLng
Lets start by creating a map and adding a regular marker with the standard look and behavior. If you’ve read the prior articles in this series you should already be familiar with the code that creates the map. Please note that I’ve used a somewhat more compact syntax here than in previous examples.
// Creating a map
var map = new google.maps.Map(document.getElementById('map'), {
zoom: 7,
center: new google.maps.LatLng(56.83, 15.16),
mapTypeId: google.maps.MapTypeId.ROADMAP
});
// Creating a marker and positioning it on the map
var marker = new google.maps.Marker({
position: new google.maps.LatLng(56.8848, 14.7730),
map: map
});
This code would result in a marker being added to the map, incidentally marking the place where I work. Note that the marker is immediately added to the map upon creation. So there’s no need, like in the old API, to explicitly add it to the map after it has been created.
Adding a tooltip
A common thing one might want to do is to add a tooltip to the marker. The tooltip is displayed when a user hovers with the mouse pointer over the marker. This is easily done by adding the property title to the marker options object.
Since this marker won’t be clickable I want to somehow indicate this. That is done by setting the property clickable to false. This results in that the mouse cursor won’t change on hover.
var marker = new google.maps.Marker({
position: new google.maps.LatLng(56.8848, 14.7730),
map: map,
title: 'My workplace',
clickable: false
});
Here’s how this will look like on the map.
Definition
- title [string]
Sets the tooltip of the marker. - clickable [boolean]
Defines whether the marker is clickable/draggable or not. If set tofalseit will not display a special mouse cursor on hover. Default value istrue.
Changing the default marker icon
Often we want to use a different marker than the default one. The API offers a simple way of doing this with the property icon. Icontakes either an URL pointing to an image or a MarkerIcon as its value. In this example I will use the more simpler, URL, and point it to this image.
This icon is taken from Nicolas Mollet’s map icon set at http://code.google.com/p/google-maps-icons/. There’s lots of similiar icons that you can use.
Here’s the code for creating a marker with a custom marker icon.
var marker = new google.maps.Marker({
position: new google.maps.LatLng(56.8848, 14.7730),
map: map,
title: 'My workplace',
clickable: false,
icon: 'http://google-maps-icons.googlecode.com/files/factory.png'
});
Now the map and the marker will look like this:
There are some other properties for more advanced control of the marker icon, such as shadow and shape. Shadow defines the shadow cast by the icon and shape defines the clickable/draggable area of the marker but I will not explain them further in this article.
Definition
- icon [string|MarkerImage]
Defines the marker icon. It can either be an URL pointing to a suitable image or an object of type MarkerImage. - shadow [string|MarkerImage]
Sets the shadow of a marker icon. Takes either an URL or aMarkerImageas its value. - shape [object]
Defines the clickable/draggable area of a marker. It takes an object as its value. The object contains coordinates that define a polygon much the same way an imageMap is defined. - flat [boolean]
If set totruedisables the shadow of the marker.
Note: By explicitly setting icon, the property shadow is reset. So even if we don’t provide shadow with a value, it will not inherit the shadow of the default marker. I could be argued that in this case the property flat should be set to true, but it’s not necessary for the marker to not have a shadow.
Other properties
Additionally there are a few other properties you can use to control the marker.
- cursor [string]
This property changes the way the cursor look when the mouse pointer hovers over the marker. - visible [boolean]
This property determains if the marker should be visible or not. Set it tofalseto make the marker invisible. The default value istrue. - zIndex [number]
Sets the stack order of markers. Could be handy if several markers sits on top of each other.
Live demo
Be sure to checkout the Live Demo to see the code shown in this article in action.
Other resources
For a full and most recent definition of the marker object check out the API reference. Also check out the section about overlays in the documentation.
My Google Maps book
If you found this article useful you might be interested in my book Beginning Google Maps API 3. It covers everything you need to know to create awesome maps on your web sites. Buy it on Amazon.com
Hello Gabriel, I am Nicolas Mollet creator of Google maps icons project (http://code.google.com/p/google-maps-icons/)
Thanks for the backlink.
Do you know any public maps (your maps ?) that use this icon collection. I am creating a list of sites using thoses icons.
You may help me on something else.
I am desperate to find how to use GM Api 3 with something like :
position: new google.maps.Address(123, Rocking Street, New York, USA),
There are places I don’t know the latitude&longitude. How can I pass the full address to the API ?
All the tutorials I find work with the coordinates, that I don’t have…
Thanks if you can help.
Hi Nicolas,
No I’m afraid I don’t know of any sites that uses your icons. I will however, probably use them in a few examples in my upcoming book, where I of course will give you credit. I really like them and it’s nice to see that the collection is growing. Good job!
When it comes to getting the coordinates for an address, you need to use the GeoCoding Service. Check out the documentation to see how it’s used.
Hello everybody ,I am a php programmer
can you help me out by giving me a script of google map in which it will point multiple addresess dynamically.
Hello Gabriel, I am Lorenzo Emanuelli; tnx for this very useful blog. I have a little problem: Google Maps Api 3 work very well on firefox for windows and mac, but on ie7 i can’t view the map, using the same code ! Have you an idea of which problem coluld be?
Tnx for your attention.
Lorenzo
Thank you so much for this. Like Lorenzo I had trouble with IE7 then I looked at the page source on your example and realized I had some mistakes in the javascript which I corrected. Hope that helps Lorenzo.
My site is focused on New England vineyards – I am trying to raise awareness and get people to visit them. The maps are very important, and with your help Gabriel, I can now put tooltips and other options.
As a graphic designer being able to follow your examples is great!
– Nancy
how to add multiple markers without separate entries like:
marker1 = new google.maps.Marker({ position: latlng1, map: myMap, title:'wdw' });
marker2 = new google.maps.Marker({ position: latlng2, map: myMap, title:'wdw' });
Hello Gabriel,
Do you have a solution for v3 to automatically adjust the zoom level so that it includes all the markers displayed?
e.g. i have multiple markers scattered on a map and i have to decide which zoom level to use… how can i do that in v3?
Thankyou
Than Polas: You can use the LatLngBounds object for this. Simply extend it with the
LatLngof each marker you add to the map and then call thefitBounds()method of the map object and pass it theLatLngBoundsobject.Assuming that myPositions is an array containing LatLng objects this is how it’s done:
// Create a LatLngBounds object var bounds = new google.maps.LatLngBounds(); for (var i = 0; i < myPositions.lenght; i++) { // Insert code to add marker to map here // Extend the LatLngBound object bounds.extend(myPositions[i]); } map.fitBounds(bounds);I hope that helps!
Hello Gabriel,
I am trying to incrust text (API v3) in the marks example, will be welcome any suggestions that you could give me in this topic.
And congratulations for this tutorial so practical and easy to deal
In advance thank you,
Regards.
Hi Gabriel
Nice articles on API 3. Have you come across any examples of using API 3 with ASP.NET 3.5? The sample javascript executes without errors but nothing is displayed. The HTML examples work OK and as far as I can see the ASP.NET renders the HTML in the same way.
I don’t want to bother you unnecessarily but I can post some examples if you’re interested.
Many thanks
Andy
Andy Clark: Hi Andy and thanks!
I haven’t seen any examples using ASP.NET 3.5 but that shouldn’t make any difference.
Make sure that you have dimensions set for the containing element of the map. In my examples it’s called
<div id="map"></div>. Set its dimensions in your stylesheet like this:#map { width: 600px; height: 400px; }If that’s not the problem, post a link and I will try to take a quick look at it.
Hi,
Nice article. So far, I haven’t been able to find any API calls in v3 to duplicate the map.clearOverlays() function in v2. Are you aware of any way to remove markers?
Thanks,
David
Hi Gabriel, a question. I’m using MapIconmaker in one of my apps (using API V2.x) just because I need to specify marker colors based in some attribute. I’m willing to migrate to V3, but, is MapIconMaker compatible with V3 or there is any other way (perhaps native) to specify the markers color (and size).
Thanks in advance,
Sandro Franchi.
David: There’s no clearOverlays() method in v3 so you have to manually keep track of your markers yourself. One way of doing that is to keep them in an array. To remove all the markers from the map you then loop through the array and remove them one by one.
See the Google Maps API v3 forum for an example on how to do this.
Sandro: MapIconMaker is currently not available for v3 but I know that at least one person is thinking about porting it to v3. Unfortunately there’s no native way of changing colors or size of the icons in v3 either.
Check out the thread about MapIconMaker in the Google Maps API v3 forum.
Hi,
Is is possible to put miltiple and different markers on a google maps ?? I want to be able to place different markers (like the logo of the company) on the map; every company has a different logo and I want to be able to look at them easily.
Thanks !
Gilles
Gilles: That’s entirely possible. You just need to create a new MarkerImage for each marker type and pass it as the value for the marker objects icon property. (or just pass an url to the appropriate image to the icon property)
Thanks very much Gabriel, it’s long time i was looking such a article so simple and clear!
Hi Gabriel
In “my maps” there is an option to display places of interest and then to choose which types of location (coffee shop, gas station, etc) to pinpoint on the map.
Is there any way of doing this in either V2 or V3? I couldn’t see it when I looked through the docs (but then there are a lot of docs to read). I would find this very useful as our users who have holiday properties to rent could simply enter lat/long of their location into our db and other users (wanting to rent) could see where these kinds of things are.
Hmmm, “simply”? Is there an API for searching by location, centering the map on an address, clicking on a button and getting an event with lat/long of the map centre?
Hi.
Great articles you have provided.
I am experimenting with adding a tooltip as described but unfortunately it doesn’t appear.
Is there something wrong with my code ?
Thanks Mike
function initialize() {
var latlng = new google.maps.LatLng(15.6256915, 73.7344704);
var options = {
zoom: 15,
center: latlng,
mapTypeId: google.maps.MapTypeId.HYBRID
};
var map = new google.maps.Map(document.getElementById(‘map’), options);
var marker = new google.maps.Marker({
position: new google.maps.LatLng(15.6191105, 73.7351704),
map: map
});
var marker = new google.maps.Marker({
position: new google.maps.LatLng(15.6188521, 73.7347090),
map: map,
title: ‘My workplace’,
clickable: false,
icon: ‘http://google-maps-icons.googlecode.com/files/factory.png’
});
}
Mike: After experimenting a bit I found that the property
clickableneeds to be set totruein order for the title to work.Hey Gabriel,
great Tutorial very clear and simple,
but i’ve a question, what do you think is the best option do manage a large amount of markers in v3? Can I still use the markermanager or work with xml files?
And i need to have categories and different zoom levels on my map but i can’t find a helpful tutorial do you have any tips for me?
Thanks a lot
Basti
Basti: Yes you can still work with MarkerManager and/or XML files. There’s also a utility library called MarkerClusterer that you can use.
I don’t know of any good tutorial on this for v3 but I’ve just finished a chapter on how to do this using the MarkerManager for my upcoming book. So if you can wait until August you’ll find a tutorial right there.
Other than that you can check out the examples in the documentation for MarkerManager.
Great explanation. I have a mini-site where you can in put a start-point and an end-point, then Google draws the journey on the map.
However the default markers are just A and B. I need control over these labels. Any help would be much appreciated?
Is it relatively easy to get a “title” tooltip to display when you load lots of markers from an xml file? I’m struggling with this.
Is it possible to have the tooltips of all markers staying on screen all the time without the need to move mouse over them?
Dominic: No it’s not. What it does is to attach a title attribute to the html element holding the marker. If you want to have a persistent label you need to use some kind of third party solution. Check out the official utility libraries currently available for v3. Maybe you could use the InfoBox library to do this.
Hi
please, give me an advice in V3.
I would like to specify a zoom level, which the marker start to be displayed with.
There was no problem to do that in version 2.
I did that with
mm = new GMarkerManager(map, {borderPadding:1});
…
mm.addMarker(marker,2,17);
How do that in V3 ?
Mirekh: There’s a v3 compatible version of MarkerManager that you can use to do the exact same thing. Check out MarkerManager at the Google Code repository.
Hi
How can i remove the markers from map in api 3.Because i have marker overloading problems..please help..
selvaganesan s: i’ve been just dealing with this problem, you have to store your marks in some variable. Array is ideal for bunch of marks. When you wanna clear them from the map and release from memory, call marker.setMap(null) for each of them.
var map = new google.maps.Map(element, options);
var marker = {};
function addMarker(title, lat, lng) {
var m = new google.maps.Marker({
position: new google.maps.LatLng(lat, lng),
map: map,
title: title
});
marker.push(m);
}
function clearMarks() {
while(m = marker.pop()) {
m.setMap(null);
}
}
20. April 27th, 2010 at 6.31 by Gabriel Svennerberg | Author comment
Mike: After experimenting a bit I found that the property clickable needs to be set to true in order for the title to work.
So shouldn’t it be changed to “clickable” in the instructions?
Wayne Sallee
Wayne@WayneSallee.com
Thanks! This is a really useful article. I’ve now managed to read data from an XML file and display markers based on categories, with options to show and hide each category. I’m currently not using MarkerManager to manage my markers (it didn’t seem to work happily with my code), but instead have added a listener to each marker to determine whether it is displayed at any given zoom level…
That doesn’t seem entirely efficient to me as I’m assuming that markers that are not visible in the map area at a given zoom level (i.e. they’re off screen) are still using resources. I guess I’ll have to persevere with MarkerManager in order to address this; assuming the map renderer doesn’t handle it?
I have one question that I haven’t seen addressed anywhere yet: Roughly how many markers can the system handle/display at any one time? From the MarkerManager documentation it sounds like it might be up to 200… Are there any recommended limits we should stick to?
I’m still at the research stage and don’t know how much data I’m going to be working with, so just want some idea of how lazy I can be with optimisation