Graeme Geldenhuys wrote 14 lines
Hi,
As the subject says. When is TComponent.Loaded called? I'm trying to
use it in fpGUI to initialize a few things in a component, but Loaded
never seems to execute.
Reading the Kylix 3 help, it says Loaded is called by the streaming
system that loads the 'form files'. Well fpGUI doesn't use 'form
files' (like *.dfm or *.lfm). Instead the GUI Designer creates the
components via code in a normal *.pas unit, which is called after the
Form's constructor has completed.
I gather it is safe to assume the FCL never calls a TComponent's
Loaded method anywhere?
It is called in the streaming code, classes.inc in TReader.ReadRootComponent
It's used to perform certain actions which should only be done after all properties are loaded.
You should never call loaded directly (in fact, you can't since it is protected).
The reason for it's presence is simple: you can't force the order of loading properties. Suppose you have a dataset component: the active property is one of the first to be set: none of the properties which actually matter (SQL, Database etc) are set, so putting active to True would raise an error. Therefore the action of setting 'Active' is deferred till the Loaded call: then the needed properties are normally all set.
When creating components in code, it's assumed that you set them in the proper order prior to setting Active.
Michael.
