Tagged value GUIDs and link to profile namespace

[fwoolz]

When "copying" tags from a base class to a derived class via the AI, I learned that, although the tag name and value copy just fine, the copied tag loses its connection to its parent profile. After doing some poking around to try and figure out how EA manages to track the namespaces of tagged values (e.g, SysML1.1::requirement::id), I noticed, by sheer dumb luck, that the first 16 digits in the PropertyGUID (ea_guid in t_objectproperties) remain constant for any and all instances of a given tag from a given profile; only the last 16 digits change. I confirmed that this was the "trick" EA uses to match tags to profiles by altering one of the first 16 digits and confirming that the link to the profile was lost ("SysML1.1::requirement::id" becomes plain vanilla "id"), then changing it back and verifying that the link was restored ("id" changes back to "SysML1.1::requirement::id")**. I haven't yet figured out HOW the connection is made, but it seems pretty clear that is how the link is specified.

** Actually I created a test profile with a stereotype "schmutz" and attributes aTag and bTag since the SysML profile is buried in my EA edition. That minor quibble notwithstanding, the link to the profile came and went as described.

Perhaps the Sparxians can lend us their decoder ring so we can figure out the method to this (clever) madness? 8-)

Cheers,
Fred W

[Paolo F Cantoni]

Interesting (perhaps in the "Chinese" sense).  

I, too, have had some of these "dumb luck" experiences...

Anyway, thanks for sharing.

(And I won't quibble  

Paolo

[Geert Bellekens]

Fred,

You should know by now that EA works in mysterious ways

Geert

[beginner]

The only thing you can learn from history is that you don't learn anything from history.

How often have we seen systems that behave chaotic? Change a flag, insert a line somewhere or do something trivial and everything goes BANG! EA is almost there. Just 2 or 3 more "features" and it will behave like Windoze 95 or like Word (any version) or the stock market.

b.