Development Guidelines for data model

[caitlin]

Moved from ​http://www.ome-xml.org/ticket/100

I suggest you create and document some style rules for development of the schemata. This will help others who wish to write reusable local extensions, new collaborators who may come into the project later, as well as present collaborators in future expansions or changes. Suggestions of the kind of rules to address:

1. A consistent approach for when to use attributes and when to use subelements
2. An ordering principle or set of principles for subelements and attributes, for example required elements first, then alphabetical. In the schema, for the definitions of each element, order subelements either according to the SAME principle as they are organized in the top level definitions (grouped by top level definition), or else order them all together without regard to the top level by some other ordering principle (like alphabetical).
3. Make a clear distinction between “unknown,” “other,” and null values. Make an unknown value on all enumerated lists, to avoid invalidation when you import metadata from less-complete file types.
4. Rules for consistency in capitalization, punctuation, and spaces
5. No abbreviations or plural nouns in element or attribute names.
6. My recommendation on language in general is to create new terms to define new concepts, and use familiar terms only if the generally accepted definition will be fulfilled in the model. I know that is a bit subjective, but please see the ticket “Experimental conditions” for an example of why I am mentioning this.

[hflynn]

@ajpatterson, should this go into the Model documentation at some point? Or do you think it belongs in the Data Model section of the OMERO developer docs? We should probably revisit how these are divided up now we have the Model docs in sphinx actually, I'll make a ticket for that.

[jamoore]

Referencing ticket #10274 has changed sprint.

[hflynn]

Development process guidance can be added to new schema changes doc in Contributing section.

[hflynn]

Should probably include some of this within ​https://trello.com/c/6BUPmEP5/231-update-https-www-openmicroscopy-org-site-support-contributing-schema-changes-html

[hflynn]

Managed via Trello now.