Determining runtime or design time during Validate - workarounds?

I've seen a couple of posts in this forum on this subject. If anyone knows of a workaround it would be great to hear.

The problem is this. I'm writing a component that looks a bit like an OLE DB destination: it writes to something that looks like a table. During design time I want the component to update the list of available destination columns if they change - so I want Validate to return VS_NEEDSNEWMETADATA if it detects a change. However during runtime I only want to validate that the component will run ok. So I still want to check what the destination looks like but if, say, someone has just added a column then my determination is it is ok to procede with the execution.

ValidateExternalMetadata doesn't help in this case because I still want to validate against the destination. I just don't want to raise VS_NEEDSNEWMETADATA during runtime because it aborts execution and I can determine that although there is a change to the destination it is not one that will cause the component to fail.

Any thoughts and experience on this would be great to hear!

Martin

Hmmm...

I can accept that if the destination changes you still want to return VS_ISVALID based on some logic that you will code. But surely the same logic applies at design-time as well doesn't it?

I'm afraid I don't know of a way to determine if the Validate() method is running at design-time or execution-time or not.

-Jamie

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Hi Jamie,

Thanks a lot for your thoughts. Yes that's right: I definitely want to return VS_ISVALID at runtime. But I need to return VS_NEEDSNEWMETADATA at design time because (as far as I understand SSIS component coding) that is the only way to instruct the SSIS design environment that you have detected a change that should update the meta data. If I didn't return VS_NEEDSNEWMETADATA then the component's meta data would be frozen until the user did something goofy like change the destination table name property to something else and then back again - we've all used too many apps like that :-)

One thing I do want to avoid is a scheme where the designing user has to remember to flick some component property when they release their package into the runtime environment.

My current thoughts for a workaround are:

1. If I create a custom UI then I would know if the user pops up the custom designer - I could delay updating the meta data until then. Pretty cheesey though.

2. I introduce a package variable which could be set by the user and checked by my component. If it is true then Validate only ever returns VS_ISVALID. I think there is something about package variables only having their default value at design time, but can have other values at runtime.

Cheers,
Martin

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Hi Martin,

the curent Validate/ReinitializeMetadata mechanism is simply not designed for this. In our definition VS_NEEDSNEWMETADATA means there is a metadata mismatch and it will most likely cause the execution to fail, so it is not a valid state.

If you need this logic to be applied only at the design-time I would put it to a custom UI. You can add extra validation and refresh services to you implementation of IDTScomponentUI, and mimic the Validate/RMD protocol.

HTH,

Bob