Date/Time Picker as Property Editor in a TCollectionItem descendant

Question

I'm writing a component which requires properties of type Date, Time, and Date/Time. I would like these properties to be visible in the Object Inspector, with an option to use a popup property editor.

I have tried TDate as a published property, and this gives me the results I need for just Date alone. However I need the same thing for TTime and TDateTime but they don't come with a property editor, and in fact it won't even accept any value I type in there either.

I have found the TDateTimeProperty which can be used as a property editor, or so I understand anyway. I have done the necessary implementation when registering this component. This property I need to apply it to is actually a TCollectionItem descendant, not necessarily a part of the component but within it.

This is how I'm registering it...

RegisterComponents('My Page', [TMyComponent]);
RegisterPropertyEditor(TypeInfo(TDateTime), TMyCollectionItem, 'MyPropName', TDateTimeProperty);

Although this compiles, when I install it, there is no property editor on this property. I have tried using my component's class name in place of TMyCollectionItem but same issue.

What am I doing wrong here to show this property editor?

Answer 1

You don't need to register the built-in property editors for TDateTime, TDate and TTime. They are already registered. That's why your attempts to register them have no impact.

The built-in property editors for these types simply convert between the underlying floating point value and a string representation. They don't implement date time pickers or anything like that.

You say:

However I need the same thing for TTime and TDateTime but they don't come with a property editor, and in fact it won't even accept any value I type in there either.

That is in fact incorrect. They do come with property editors. They are the same built-in property editors that you named in your question. And they do accept values. They don't accept the values you provided because you provided invalid values.

If you want to register a property editor that does provide a visual date time picker, then you will have to write the property editor yourself.