Here is an interesting problem regarding the IncludeEventHandler.
I am developing a Spring-Based application which uses velocity which has different VENDORS having a separate portfolio site. I am letting vendors customize the pages by providing them the Velocity templates which are being stored the database and are picked up by the velocity engine using a DataSourceResourceLoader.
My table is organized like this.
The vendors may parse other templates by calling the macro #parse and passing their vendorid/template-name so that it looks like this.
#parse("20160109144/common-css.vm")
Now the actual problem is picking up the template according to vendorid.
I have a class (extending IncludeEventHandler) which overrides the includeEvent method. Now what can I do to return the desired template? I dont want to change the names and make them look like 20160109144/home.vm
With OP's question, the intent was to provide an alternate behavior to the DataSourceResourceLoader.
Unfortunately, the Velocity Engine version 1.7 doesn't have ability to change the SQL statement that is used to retrieve the template.
The DataSourceResourceLoader extends the ResourceLoader abstract class. That said, if you reference the source, you should be able to implement a custom ResourceLoader that behaves the way you want it to.
One option, glom most of the code from DataSourceResourceLoader and change the way it determines the template content to load from the database.
I would dump all of the query related material as you will be determining the specific columns you want to load for content. The DataSourceResourceLoader essentially maps the name of a template to a database entry and your implementation essentially revolves around the rules you've defined above.
Hopefully that can provide enough assistance to move forward. I would recommend pulling this in a debugger as well and determine what is and is-not passed in to the related load methods.
