The ORM Foundation

Is there a practical use case for including elements in a model that aren't displayed on any diagram?  NORMA permits this by providing a choice of whether to delete the underlying model element when deleting the model element's final shape from a diagram.  Because the answer to this choice defaults to "No", I wonder if some modellers inadvertently retain unwanted elements in the model but forget about them because they are not displayed.

Thanks,
Matt

 NORMA allows an ORM schema to be displayed on many pages. The same model element may be displayed on many pages. It can be convenient to remove some shapes from a page to better focus that page on a specific subarea of the overall schema. There's probably little practical value in removing the final shape of a model element if you want to retain the model element in the model, but if you do this you can always find it again in the Model Browser and drag into onto a diagram page. 

Cheers

Terry 

Hi Matt,

The diagrams are built as views on top of the model, not the other way around. The core model doesn't even know the diagramming layer exists, including UI-only concepts such as 'ExpandRefMode'.

The only shapes that routinely don't display are those collapsed in a reference model (ENTITY(.Id)). It is also possible to have constraints in the model that are no longer displayed because the fact type or subtype the constraint was attached to was moved to another diagram.

Along with supporting shape coloring, the Shape Grouping extension (in the NORMA Pro extensions mentioned in http://www.ormfoundation.org/forums/p/1054/3321.aspx#3321) has a group type that automatically tracks items with no current shape. I don't usually leave this on, but I'll flip it on occasionally to see if I've left anything dangling. To use:

1. Add the Shape Grouping extension using the Extension Manager.
2. In the ORM Model Browser, add a new group by right clicking on the Groups folder (rename the group as appropriate).
3. With the new group selected, open the Properties window and expand the GroupTypes property.
4. Select the ORM Shape Missing group type.

Hi Terry and Matt,

Thank you both for your responses.  The ORM Shape Missing group type is very helpful---I was unaware of that capability.  Do you think it would make sense to change the default settings such that NORMA warns the user of elements that aren't displayed unless the user explicitly suppresses that warning message?  I suspect that in many cases the existence of an element that isn't displayed is an accident on the part of the modeller.  

To validate an ORM-based tool I'm building, I'm analyzing a set of models produced by third parties.  In many cases, the models contain a large number of elements not displayed on any diagram.  I suspect that these are cases in which the original modeller intended to delete the model element by pressing delete followed by enter, which only removes the final shape but not the element itself.

Matt