Sample Application: difference between host an web module

[Abid Hussain]

Hello,

I'm new to Impala and am currently evaluating it (in comparison to
OSGi).

I tried the ant script to build the sample application and wonder why
the host and web module are divided into two parts because they both
represent the same web application, don't they?

In the wiki (http://code.google.com/p/impala/wiki/GettingStartedPart1)
it says about the web part: "Unlike the host part of application, this
project contains web components which can be dynamically reloaded."

Can anybody help me with some explanation?

Regards,

Abid

[Phil Zoio]

Hi Abid

The module structure is documented here: http://code.google.com/p/impala/wiki/ModuleStructure

Basically, the host project is just a simple Java/Spring web
application, enabled to support Impala modules. You can run a bog
standard Spring application within the host project.

A 'web' module is a type of module which you use within an Impala
application to support web elements which have the Impala capabilities
- dynamic reloadability, ability to dynamically configure, etc. In a
decent sized real project you would have quite a few web modules.

Classes and resources within the host module are visible to web
modules, but not vice versa.

Ideally, you would want to keep your host module quite small, with
only a web.xml, and potentially some commonly used JavaScript files,
resources, etc. Any 'module-specific' web elements (classes,
controllers, resources) would normally go in the relevant web module.

Hope that helps.
Phil