Skip to main content

Geocoding

    Geocoding is the process of converting addresses (like "Pune") into geographic coordinates (like latitude - 18.5193 and longitude - 73.8579), which you can use to place markers or position the map. The Google Maps API provides a geocoder class for geocoding addresses dynamically from user input. Accessing the Geocoding service is asynchronous, since the Google Maps API needs to make a call to an external server. For that reason, you need to pass a callback method to execute upon completion of the request. This callback method processes the result(s). To know more details about the geocoding requests, responses and results visit this link.

    Understanding the geocoding requests, responses and results is very important for proper understanding and execution of any geocoding functionality in Google Maps API v3. Let us have a look at the following example...



    The output of the above code will appear as seen in the results section above. The map is initially centered at India, with no text in the search box. Now you need to put in the address that you wish to geocode in the search box and then click on search. If the entered address is valid, a marker will appear on the map at the appropriate location.

    There is some level of error-handling done in this example using the status codes of the geocoding facility in Google Maps API. The status codes return several values depending upon whether the geocode was successful or not and whether any result was returned. The following image will show one such condition where the geocode was successful but did not return anything as the entered address was invalid.


    Some may find the above example a little complex, but the example is not complex at all, it is just that you need to understand the geocoding requests, responses, results and status codes. If anybody wants me to write in depth about the theory of the geocoding, then I will definitely try and write to explain the stuff in as simple language as possible. Till then...Keep mapping!
Labels:

Comments

  1. GaryApril 1, 2011 at 10:29 AM

    Shreerang Patwardhan,
    Pardon me for asking but is your first name Shreerang or is it Patwardhan. Reason I ask is because when I was in college some of my foreign student friends addressed themselves with the Last name first and First name last. I would like to know out of respect to addressing you.
    My email is to let you know I enjoy your sharing of your skills in computer data building language with all of your followers on-line this is quite generous of you doing so. My real question is to ask you well... how do I start in this process of creating this task of data language inputting? Do I simply open a word document or a spreadsheet to input the info in? I am kind of a novice as you can tell by now. I thought I read some wheres you saying to open a browser... not sure which or what browser, if that is what you might have said at one time to do in order to do the language build. Can you help me through this process, by perhaps sending me a set of instructions to follow to get started? I would surely appreciate it a whole heck of allot. These little gifts of yours to the general viewer of creating a data language input then into an actual visual representation that one can use and work in is quite fascinating to see happen and to know just what it is that “you” as an industry career if only in part.
    So I ask you if I may can you help me with this journey in my learning something new?
    Thanks so much for your time and effort
    Best Regards,
    Gary Bertolo

    ReplyDelete
  2. Shreerang PatwardhanApril 4, 2011 at 2:29 AM

    Hi Gary...My first name is Shreerang...:)Happy to hear that you enjoy my blog. I also enjoy sharing my knowledge with the tech community and would be more than happy to help you out...
    First of all you need to start from the basics if you need to learn something like Google Maps API. If you just enjoy browsing the maps and don't really wish to code then all you need to do is copy the code in the posts and paste it in a normal text file. You can use notepad, wordpad, MS Word if you use windows and gedit, notepad, Open Office Word if you use Linux for the same purpose. Once you have copied the code in one of these files you need to save these files with ".html" extension and not with ".txt" or ".doc" extensions which would be the default ones. Once you get around this, you can double-click on this file and it would open up in your default web-browser.
    Now, the thing is that the code into consideration is javascript. Each browser renders javascript differently. So a map that appears perfect in Firefox, might not work in Google Chrome or IE...Firefox is the best...
    Hope this helps you get started...And if wish to learn google maps API...then you can start reading my blog from the very first post...
    Hope you enjoy my blog...Any suggestions are welcome...
    Thanx for your appreciation.

    ReplyDelete

Post a Comment

Please leave your comments here...

Recommended for You

Where does Google get it's live traffic data from?

Referring to a post that I wrote earlier, Google’s - Live traffic Layer , ever wondered how Google collected this data? I was wondering the other day, how Google received live data to display it on their maps as a layer! I looked up the web and found something very interesting and am sharing the same with you all. As we all know, the traffic layer is available most accurately in several states in USA. Most major metro areas in the US have sensors embedded in their highways. These sensors track real time traffic data. Easy to miss at high speeds (hopefully anyway, traffic permitting), more commonly noticed may be the similar sensors that often exist at many busy intersections that help the traffic lights most efficiently let the most amount of people through. The information from these tracking sensors is reported back to the Department of Transportation (DOT). The DOT uses this data to update some of the digital signs that report traffic conditions in many metro areas. They als
17 comments
Read more

Playing with the markers and info window bubbles...

    In the last few posts, we have seen some marker examples and some information window examples. Now, lets do something interesting combining these two things. Just writing that "This is an info window" in the information bubble is not very interesting! And I know this...Have gone through the same phase!     So, today we will do something interesting! We will display the latitude- longitude co-ordinates of the point that the user clicks on the map! Doing this is not at all complex! Copy paste the following code and you will see for yourself a map coming to life!     The output of the above code looks as seen in the result section above! If you have any queries regarding the above code please comment on the blog post or feel free to contact me at my mail ID .
3 comments
Read more

Geodesic Polyline

    Today we will have a look at a very interesting polyline example - "The geodesic polyline". Now the first question that will pop is "What is geodesic?". Mathematically, geodesic means the shortest line between two points on a mathematically defined surface, as a straight line on a plain or an arc of a great circle or sphere.     The next question after reading the above definition is clearly, "Why do we need geodesic polylines?" and that would be followed up with "What is this Great Circle?". We will discuss this first, before we move on to the actual example today. The example is very very similar to the normal polyline example, with just a small change.     Having said so, I will now try to explain why we need a geodesic polyline? The shortest distance between two locations on the earth is rarely a straight line as the earth is roughly spherical in nature. So any two points on the earth, even if they are very close lie on a curve and n
5 comments
Read more

Form info window

         Today we will look at a Google Maps API v3 example to add a form in the information bubble! This is usually required when we wish to accept some data/information from the user! This data can be saved to a server in the form of an XML file or a database! The information can then be retrieved back at a later stage, when necessary!          In this example we will only look at form in the information bubble! The connectivity part with the server will be discussed in another post! So, today's code snippet is as seen below! <html> <head> <title> Google Maps API v3 - Adding marker and info window on Click and creating a form in the infowindow with the lat-lng information in it. </title> <script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script> <script type="text/javascript"> var map;    //When using event as a parameter to a function declare map, strictly as a
5 comments
Read more

Retriving co-ordinates...

         We have seen 2 Google Maps API v3 examples wherein we have retrieved the latitude-longitude co-ordinates of the point of click on the map. In the first example we have displayed the co-ordinates in the information window and in the second , we have displayed the co-ordinates in a form in the information window.         Today we will create a code to retrieve the latitude longitude co-ordinates in a text box while simultaneously a marker appears on the map as well. So, here goes the code. <html> <head> <title> Google Maps API v3 - Adding marker on Click and retrieving the co-ordinates in a text box </title> <script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script> <script type="text/javascript"> var map;    //When using event as a parameter to a function declare map, strictly as a global variable function initialize() {     var myLatlng = new google.maps.L
4 comments
Read more