Re: Generic-Table Retrieval/Display - DatabaseMap ?

[Rankin Johnson]

I've checked it out.
I apologize in advance for my abject ignorance here, but how do I apply 
it? 
'patch -p 0 < ./proposals/henning/mapbuilder-init/mapbuilder-init.patch' 
doesn't work.

Henning P. Schmiedehausen wrote:
rankin <[EMAIL PROTECTED]> writes:
You might want to check the TORQUE_3_1_HENNING branch from the db-torque CVS.
In a nutshell: Yes. I fell into the same trap and this Torque branch has a
method in the MapBuilder to initialize all the tables of a database map.
        Regards
                Henning

 

A further problem in implementing this:
   

 

It seems the DatabaseMap object is "lazily-built"; that is, tables are 
only added to the map after they're specifically requested.  When this 
app first comes up, all I see in the table drop down are: TURBINE_USER, 
GROUP, etc.  If I use a particular table thru some other template, it 
will appear in that drop down next time.
   

 

Does anyone know of a property in TR.props which will cause the 
DatabaseMap to be built out upon initialization, or of any method which 
can be called to cause the same thing to occur, or do I have to get a 
connection to the database and go get this metadata myself?
   

 

Thanks, in advance.
   


 

rankin wrote:
   

Thanks for the reply, I was unaware of beanutils.  It looks to be an 
improvement over the less generalized reflection I've been poking at:

public List list(String ofWhat){
 String peerName = MODEL_CLASS_PREFIX + ofWhat + "Peer";
 try{
   Class peer = Class.forName(peerName);
   Object o = peer.newInstance();
   return ((BasePeer)o).doSelect(new Criteria());
 } catch (Exception e){/*do something*/;}
 return null;
}
I'll look into it & try it.
But I was assuming there was some simpler method of accomplishing the 
same goal where one doesn't need to know this kind of stuff.  This would 
seem to be a question that would crop up often, especially at the 
beginning of a project or for proof-of-concept work.

Russell Edens wrote:
     

Rankin said:
       

I have many tables, which for the moment are separately defined. I want
one template, DisplayTable.vm, to display any one of these tables. So,
DisplayTable.java has:
public void doBuildTemplate(){
 ...
 String tablename = data.getParameters().getString("tablename",null);
 Criteria crit = new Criteria();
 List list = [**tablename**]Peer.doSelect(crit);
 context.put("list", list);
 TableMap tmap = Torque.getDatabaseMap("mydb").getTable(tablename);
 ColumnMap[] cMap = tmap.getColumns();
 Vector names;
 for(int i = cMap.length -1; i >=0; i--)
    names.add(cMap[i].getColumnName());
 context.put("columnNames", names.toArray());
 ...
}
and DisplayTable.vm has
<tr>
#foreach ($columName in $columnNames)
 <th>$columnName</th>
#end
</tr>
#foreach ($item in $itemList)
<TR>
 #foreach ($attribute in $columnNames)
 <TD>$!{item.$attribute}</TD>
 #end
</TR>
#end
I'm sure this has been done many times far more easily and other
suggestions would be greatly appreciated ... However - how does one do
the "[tablename]Peer.doSelect(crit)" bit?
Suggestions??
         

If you want to do it generically reflection is your best bet.
You might consider the org.apache.commons.beanutils.MethodUtils class for
making these calls.  Un-tested example:
private List  invokeDoSelect(String 
fullyQualifiedTorquePeerObjectName,                              
Criteria crit)
{
   final Class[] doSelectParamTypes = { Criteria.class };
   final Object[] doSelectParams = { crit };
   Object results = null;
   try
   {
       Class peerClass = 
Class.forName(fullyQualifiedTorquePeerObjectName);
       results = MethodUtils.invokeExactMethod(peerClass, "doSelect",
doSelectParams, doSelectParamTypes);
   }
   catch (NoSuchMethodException e)
   {
       // TODO handle this
   }
   catch (IllegalAccessException e)
   {
       // TODO handle this
   }
   catch (InvocationTargetException e)
   {
       // TODO handle this
   }
   catch (ClassNotFoundException e)
   {
       // TODO handle this
   }

   return (List)results;
}
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