Object name stored in Database table

Question

Hi all,
Lets say I have a Database table that contains the name of the window
objects that I want to create and display at run-time, how do I go about
creating that object from the table field wich is a string ?
Example :
MenuTable { ItemNo, IsFolder, ParentFolder, PromptMsgNo, ..., WindowName,
StartMethod }
Then I use this table to fill in a TreeView or OutlineView using a
Subclassed DisplayNode that contains
the WindowName and WindowMethod fields.
When the user selects a node I want to instantiate an object of the type
indicated in WindowName and
do a start task of the method indicated by WindowMethod for WindowName.
How could I code the following lines ? :
theWindow : "--> Content of CurrentNode.WindowName" = new;
start task theWindow."--> Content of CurrentNode.WindowMethod";
Goal :
Be able to customize the menu system without customizing code for each
client.
Any idea on alternative methodes to reach the the goal would also be
appreciated.
Thanks in advance.
Christian Boult ([email protected])
Systemes Influatec inc.

Answer 1

Hi Christian,
When the user selects a node I want to instantiate an object of the type
indicated in WindowName and
do a start task of the method indicated by WindowMethod for WindowName.
How could I code the following lines ? :
theWindow : "--> Content of CurrentNode.WindowName" = new;
start task theWindow."--> Content of CurrentNode.WindowMethod";---<<<---
cl : integer = 0;
aLib : Library = task.part.findLibrary(projectName = 'MeineTestKlassen',
distributionID = 'test',
compatibilityLevel = cl,
libraryName = 'meinetes');
aType : ClassType;
myObject : Object;
// myObject : meinNeuesObjektClassTypeName;
aType = aLib.FindClass(className = meinNeuesObjektClassTypeName);
myObject = aType.InstanceAlloc();
myObject = (object)(meinNeuerStream.ReadSerialized());
--->>>---
This code is part of a method that stores objects persistent into a Database
and then restores and instantiates them.
You'll have to put the Name of the Class your Object should be of in the
"meinNeuesObjektClassTypeName" Attribute. Then, aType.InstanceAlloc()
instantitates an Object of the given Class.
Please note that, due to the diefferences between the declared and the
runtime class type (Object vs. whatever class your object is of) you'll have
to cast your Object to the correct class. (I used to create a virtual
Superclass for this, which contains the method(s) to be called and the
needed Attributes and then cast all created objects to that superclass).
(You might also use a Template for this and implement that in all classes
that need it -- but I didn't try it yet, so I don't know if it really
works).
Hope that helps...
ralf
/* Ralf Folkerts
Geschaeft: [email protected]
Privat: [email protected] */
-----Urspr&uuml;ngliche Nachricht-----
Von: Christian Boult <[email protected]>
An: Forte Maling list <[email protected]>
Datum: Dienstag, 31. M&auml;rz 1998 04:59
Betreff: Object name stored in Database table