Ajax Autocomplete List Cities JSON-P API
Here is an example of how to add an Ajax Autocomplete Cities List to any website without generating any cross-site scripting errors, and without the need for any server side code or proxies. Fortunately there is not a lot that you need to know to get this running, but if you are interested in knowing how it works and why it does not raise site cross-scripting errors, then checkout the links below the following sample code. This script requires no server side code (php or otherwise) as it uses one of Geobytes' free web services to get the list of cities. OK, first here is a demo:
And here is the fully working example code sample (Please click on the link and it will dynamically insert the sample code inline here. It is hidden by default to save room - so that you can see the effect selecting a city above has on the Cities Details table below.).
Click here to open and close the code sample inline
Next, let's take a look at how we use the selected city to fetch and display the city's details....
Once again, let's start with a demo (Hint: Change the city in the above box to watch the city details change here.):
| Country Code | Country |
|
|
| Region Code | Region | ||
| City Code | City | ||
| CityId |
Fully Qualified Name |
||
| Latitude | Longitude | ||
| Capital City | TimeZone | ||
|
Nationality Singular |
Population | ||
|
Nationality Plural |
CIA Map Reference |
||
| Currency |
Currency Code |
For a comprehensive description of each of the above fields please see the Understanding the Geo Tags & Geobytes Headers page.
Once again, click here to open and close the code sample inline
If you need assistance implementing this, or if you have any suggestions or improvements then please feel free to post them in our support forums here.
Do I need an API Key?
No, but if you expect to be performing more than 50,000 requests per day (your average unique visitors X 5), then please tell us. (You could even consider buying $10 worth of Mapbytes so that you have a current account in our system - but you certainly don't have to.)
OK, So how does it work, and why doesn't it raise site cross-scripting errors?
Well basically, it is because we pass back a function that defines an array containing the data for the autocomplete list rather then just the data itself. This then allows the returned object to be used with a <script> element, via a process known as "script element injection" . There is a lot more to it then that, so rather than duplicate information from other sources, here are some links:
JSONP: http://en.wikipedia.org/wiki/JSONP
Same origin policy: http://en.wikipedia.org/wiki/Same_origin_policy
Why is the service free, and is it totally free - no ads, no links, nothing?
Yes it is totally free - no ads, no links, nothing. You may have notice that we offer a number of free and mostly free services, and hopefully you also noticed that we also offer an even larger number of paid services - well the short answer is that we make our money out of our paid services, and gain recognition via our free services which helps us sell more paid services. So we really don't mind doing it, and besides we have been in this business for well over 10 years now (since 1999) and since the beginning we have always tried to give something back, and this philosophy has served us well.
How do you limit the search results to a country, state, or region?
Just add &filter=XX where XX is the country's TLD such as US or UK etc., to the getJSON call. So for example, if you wanted to only list cities within the United States then you would update the getJSON call to something like this:
http://gd.geobytes.com/AutoCompleteCity?callback=?&filter=US&q="+request.term
Plus you can limit the autocomplete results even further by adding the state or region code as well - so for example you could limit the city list to cities within California by setting the filter parameter to USCA - which would look something like this:
http://gd.geobytes.com/AutoCompleteCity?callback=?&filter=USCA&q="+request.term
You may notice that "USCA" is actually the Geobytes Location Code for California - try typing San Francisco into the above city text-box and then checking the "Region Code" in the City's details table - this is a good way to findout the codes for other places - including those that are outside the US.
Is the search limited to the first few letters or does it search the entire city name, including the country name?
Both - first we search for an exact match on the prefix of the city name, then we search for a partial match any where within the full name of the city, including the country name. This ensure that cities like Occoquan, VA, United States don't get buried by all the cities in Morocco.
Like it, or lose it!
