As a starting point, here is what I have done in my private branch. It's not
perfect and I'm looking for feedback before suggesting we introduce these
changes to CVS.
I created a parallel set of classes DbEventInterceptorSupport2,
DbEventInterceptor2. With the difference being they use the
InterceptorParameters class to pass parameters to the preX() and postX()
methods.
I modified Table.processInterceptors() to determine which interface to use
at runtime. The class DbiChooser, makes the calling pattern sequence the
same.
I plan on adding setData(Object) and getData() to InterceptorParameters, to
pass data between preX() and postX(). But I have not done so yet, it would
require a lot of changes and deadline was approaching.
=====================
> We have had this discussion sometime ago.
> With the result that we should'nt break backward compatibility. And i
> have had the idea how to:
> Just change the interfaces. Implement the new interfaces in the
> default implementation classes. There you make an tranformation
> between the old and the new interfaces and call just empty procedures with
the old interface.
> So everybody can use it's old code - the methods will be called
> through overriding.
This would translate to public class DbEventInterceptorSupport2 implements
DbEventInterceptor {},
Correct ?
Then I wouldn't need to the DbiChooser anymore.
I'll have to see if that's doable.
Neal Katz
======================
Some random snippets.
public class InterceptorParameters {
HttpServletRequest request = null;
Table table = null;
FieldValues fieldValues = null;
DbFormsConfig config = null;
Connection con = null;
DatabaseEvent databaseEvent = null;
String keyId = null;
{
public DbFormsConfig getConfig() {}
public DatabaseEvent getDatabaseEvent() {}
...
}
public class GradeInterceptor extends DbEventInterceptorSupport2 {
public int preInsert(InterceptorParameters iparms)
throws ValidationException {
HttpServletRequest request = iparms.getRequest();
}
}
public class DbEventInterceptorSupport2 implements DbEventInterceptor2 {
public int preInsert(InterceptorParameters iparms)
throws ValidationException {
return GRANT_OPERATION;
}
...
}
public interface DbEventInterceptor2
{
int preInsert(InterceptorParameters iparms) throws ValidationException,
MultipleValidationException;
...
}
public class DbiChooser {
DbEventInterceptor dbi = null;
DbEventInterceptor2 dbi2 = null;
InterceptorParameters iparms = null;
public DbiChooser(DbEventInterceptor a) {
dbi = a;
}
public DbiChooser(DbEventInterceptor2 a) {
dbi2 = a;
}
/**
* @return
*/
public InterceptorParameters getIparms() {
return iparms;
}
/**
* @param parameters
*/
public void setIparms(InterceptorParameters parameters) {
iparms = parameters;
}
/**
* @param map
*/
public void setParams(Map map) {
if (dbi != null) {
dbi.setParams(map);
} else if (dbi2 != null) {
dbi2.setParams(map);
}
}
/**
* @param request
* @param table
* @param fieldValues
* @param config
* @param con
* @return
*/
public int preInsert(
HttpServletRequest request,
Table table,
FieldValues fieldValues,
DbFormsConfig config,
Connection con)
throws
MultipleValidationException,
ValidationException,
ClassNotFoundException {
if (dbi != null) {
return dbi.preInsert(request, table, fieldValues,
config, con);
} else if (dbi2 != null) {
return dbi2.preInsert(iparms);
}
throw new ClassNotFoundException("no interceptor");
}
}
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