Mobile Ajax
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AJAX
Asynchronous JavaScript and XML (Ajax) is a combined technique for developing smart-client web application. Ajax is asynchronous in that loading does not interfere with normal page loading. JavaScript is the programming language that Ajax function calls are made in. Data retrieved using the technique is commonly formatted using XML, as reflected in the naming of the XMLHTTPRequest object from which Ajax is derived.
Ajax uses the following
- XHTML as markup language and CSS as styling information
- DOM accessed with a script language
- XMLHttpRequest object to communicate with the server asynchronously
- XML as the message format to transfer data
We have seen how AJAX has done a face-lift of the well known web applications. It has headed to the mobile space.
Mobile Ajax
MobileAjax is based on Mobile JSF. The JSF page is UI component based and Ajax can refresh just components which need to be refreshed on the page. By adapting the JSF components with Ajax support, the XMLHttpRequest object can be used to check the states of JSF components from the server and just refresh those needed.
There are many open-source projects of Ajax for the JSF framework. There is a table providing an overview of these projects at http://www.ajaxjsf.net.
Advantages
Low communication traffic makes Ajax prefect to go with mobile applications. Expensive, low-bandwidth and small screens are the main limitations for mobile applications. Ajax can upload and download just the necessary data for the pages. This will highly reduce the traffic and communication time.
Limitations of AJAX and Web 2.0 on mobile Web browsers
No widespread full Flash capabilities or JavaScript technology Limited screen size, memory, and CPU power
Java ME technology addresses these limitations
Stripped down VM and libraries tuned for reduced capacity devices
Primarily subset APIs New APIs specifically for mobile applications Can run Rhino engine to give JavaScript technology support
OpenLaszlo
Open Source Rich Internet Application (RIA) Framework
Rich and robust application delivery
Multi-runtime: Rendered in Flash, DHTML, or Java ME Technology
Introduction to OpenLaszlo:
OpenLaszlo is an XML-based and we can Use our favorite editor
It has Source-control and Library mechanism (for modularization)
Its a familiar methodology for software engineers, and we can use standard OOP features
● Runtime independent tags and APIs
● No ActionScript, DOM, etc.
● Interface with server via XML over HTTP, SOAP, XMLRPC, and Java API for XML-based RPC (
JAX-RPC)
●Runtime constraint system ●Hierarchical data binding with XPath ●Media, streaming support ●Extensible UI component framework
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