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分类: Java
2006-02-07 11:51:00
Russ Nemhauser, head of Nemhauser Media Inc., on Jan. 31 discussed the benefits of Microsoft's Atlas tool for doing AJAX development.
Nemhauser said one of the major problems with AJAX development is complexity.
"I find it challenging enough to keep up with the technologies I have to keep up with, let alone to have to deal with manual creation of event handlers, messaging, client-side script, etc.," he said, speaking of tasks he would have to perform to do AJAX development from scratch.
"JavaScript is not an object-oriented language. It does not have strong typing; there is no exception handling; and there is no inheritance. One of the biggest problems with the AJAX approach is the amount of time it takes writing and debugging all that code," he said.
"So wouldn't it be nice if somebody could do all that for you?" he asked. "The answer is Atlas."
Atlas, an upcoming Microsoft technology currently available as a CTP (Community Technology Preview), is an extension to Microsoft's ASP.Net 2.0. The December 2005 CTP is the latest release available.
Nemhauser said Atlas provides all the functionality of AJAX; it greatly reduces complexity; and it "brings true object-oriented development to the client."
In addition, Atlas provides cross-browser compatibility, "so you're not tied down to a single browser," Nemhauser said. And it adds common client behaviors such as auto complete features, drag and drop capability, and pop ups, he said.
Nemhauser said with AJAX the asynchronous communication occurs between the browser and the server.
"Asynchronous calls are key here," he said. "Users can continue to work, and the data and user interface change dynamically right before their eyes."
AJAX uses the XMLHTTP protocol to contact Web services.
"The key to all this is JavaScript," Nemhauser said. "There is extensive use of client script, and because it runs to the client we get better application performance."
Nemhauser then demonstrated classic examples of AJAX in action, including Google Suggest and Google Maps.
Nemhauser, a consultant familiar with the Microsoft environment, spoke to a packed, standing-room-only crowd that spilled out into the hallway.
"Microsoft is trying to make it easy for people to create truly rich client applications over the Web," he said. "When AJAX is released, you'll be able to do things on the Web you never thought possible."
Atlas reduces the amount of code required for an asynchronous server call, Nemhauser said.
It also allows declarative programming, provides Atlas Web services, and takes advantage if the power of the client.
Meanwhile, the Atlas client components add a browser compatibility layer that "works all the differences out" so that Atlas-based applications effectively cover "all modern browsers," he said.
In addition, the Atlas core services extend JavaScript to support classes, namespaces, event handling, inheritance and data types, Nemhauser said. And the Atlas base class library supports string handlers, debuggers, timers and tracing.
Also, the new networking layer in Atlas handles all communication to and from the Web-based services and applications. "
It manages all the asynchronous calls for us," and enables calling a Web service directly from JavaScript, he said.
Nemhauser, who said he got a start in development as a Visual Basic 3 developer, said before AJAX he did not believe Web applications could provide rich interfaces.
From his early experience, "I missed all the processing you could do in Windows Forms apps," he said, noting that he had thought "a powerful UI simply was not possible in a Web environment."
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