Of course, one of the most frequent found comments on XML in general is that the XML files can become quite large (maintainability would suffer). When you are using versioning systems like CVS or SVN, merging situations can occur and will result in invalid XML. The problem becomes bigger of course if the file is large.

We recognized this issue when designing QAFE and tackled this problem by supporting automatic merging of QAML, QAFE’s XML, files.

As stated before, the QAFE applications can consist of several tiers, i.e., layers:

• Presentation tier (the part where the UI and events are defined)
• Business tier ( the layer between the presentation and the integration, which should consist of business actions. These business actions can combine calls to (different kinds of ) services and implement some control logic on top of that (including exception handling))
• Integration tier (the low level, yet technology independent definitions of services, so the question here is “which methods/procedures from the specific implementation do you want to use for the business tier?“)
• Resource tier (the specific location and implementation of the java class or database schema)

Of course, each of these tiers can be defined in separate XML files. For example:

• myapplication-presentation.xml,
• myapplication-business.xml,
• myapplication-services.xml ( one can combine the resource tier and integration tier).

Note: This also allows you to define specific roles for the project you are working on, like someone is responsible for the presentation tier, etc.

In the application-config.xml (the startup file for QAFE applications) we assemble the application as follows:

<application id="my application" name="My Application" >

	<application-mapping-file location="myapplication-presentation.xml"/>

	<application-mapping-file location="myapplication-business.xml"/>

	<application-mapping-file location="myapplication-services.xml"/>	

</application>

These files will be merged to one application. Of course, if you want to reuse the services and business part, you always can since these files are reusable now.