Google Earth and all that buzzzzzz.....
Hi there, don't we just love Google Earth... I mean ... its awesome isn't it (http://earth.google.com/)??? Changes the way we look at maps and imagery. I installed it some time back ... and love to 'travel' or 'fly' whenever I am bored with work. I think GIS and non-GIS users are getting a kick using it. Its also got a lot of traditional GIS vendors (including ESRI) pointing fingers, scratching heads and comparing it with their own internet mapping products... its got the industry all excited and buzzing. Some are being defensive.
Well... after a little bit of research... okei, about 15 mins that is... gmail and google earth is actually based on something cool called AJAX. Ajax is a name given to a set of tools that previously existed in JavaScript. The main component is XmlHttpRequest, a class usable in JavaScript. It was around since IE4.0, can u believe that??The same concept was also named XmlHttp... okei, thats before the Ajax name became so commonly used.The use of XmlHttpRequest in 2005 by Google, in Gmail (yes... gmail too) and GoogleMaps has contributed to the success of this format. But this is the name Ajax itself that made the technology so popular... sweet!!!
There are some serious development using AJAX within ESRI... for ArcIMS and also ArcGIS Server. Read here:
http://forums.esri.com/Thread.asp?c=64&f=1333&t=170129#508529
http://forums.esri.com/Thread.asp?c=64&f=783&t=162354#504133
http://forums.esri.com/Thread.asp?c=64&f=783&t=175435#516915
http://forums.esri.com/Thread.asp?c=64&f=1333&t=159693#479501
Actually... from what I can see and understand (in plain English)... AJAX is adding a new middleware between the client (your web browser) and the server (web server and database backend). This new middleware is placed on the client side.
The client user activity on his/her web browser leads to program calls on the client side... instead of sending the request each time to the server. The data transfer between the server and client uses XML. Cool... I think this is a solution to many applications that find it slow and demanding to communicate with the server... like ActiveX, Applets or even Flash.
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