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!

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