Roma UI omits attribute classes when elements are selected on-the-fly; yet, when an ODD is uploaded, the attribute classes are displayed correctly

[rvdb]

When an element is selected in Roma, not all of its attribute classes are being displayed in the "Attributes" screen for that element.

Following steps should illustrate the problem:

1. create a new ODD, based on the "TEI absolutely bare" template
2. select the <name> element --> "Attributes"

There, following attribute classes are missing: att.canonical, att.editLike, att.global.source, att.naming, att.personal. Yet, in the the generated tei_bare.odd, there's no trace why these classes should be missing.

Additionally, when this same tei_bare.odd file is uploaded in Roma, all of these attribute classes are shown, so this seems like an UI bug (at first, this issue seemed related to #101, but I'm not sure.

[raffazizzi]

A note as I look at this issue over several sessions....

This is a very interesting situation. Let's focus on att.canonical, which is inherited via att.personal.

When the ODD is first loaded, no element is using att.personal therefore it's dropped from the ODD by the XSLT processor. When name is added, Roma sees that att.personal is excluded from the schema so it won't add it to name.

When the ODD is loaded back, name is now selected, which means that att.personal does not get dropped from the processor.

The solution, I think, is to check whether the class (e.g. att.personal) is explicitly excluded and if not, it should be restored before adding the element that uses it (e.g. name).