Hi Alexios, I don't have an ontology background, so forgive me if this is a silly question, but "Classes and Attributes" sounds like they belong in the domain of software design, while "Data" does not depend on how software used to write and read the data is implemented. Software could be written in C or Java or Python, using classes or not using them, and as long as the data creator and the data consumer use the same data they are interoperable.
So I'm particularly confused by "There is no information like “1:N” on purpose; it’s a little confusing to have a class diagram also look like an entity-relationship one." When defining a data structure, it makes a big difference whether there is a single required element (1..1), a single optional element (0..1), or an array of elements (1..*) - multiplicity is a critical part of the data model that cannot be left out. There might be a place for class diagrams and entity-relationship diagrams somewhere in SPDX, but the data model is the part that must be defined unambiguously in order for writers and readers to agree on the structure of an SPDX document. Regards, Dave On Wed, Apr 22, 2020 at 5:14 AM Alexios Zavras <[email protected]> wrote: > Hi all, > > > > As some of you may know, we have been using an ontology (expressed in OWL) > to represent the SPDX classes and attributes; we also have a graphical > representation of the SPDX data model. These reside, respectively, in the > directories “ontology” and “model” of the spdx-spec repository. > > Although these essentially represent the same thing, for historical > reasons they were actually independent “sources of truth”. > > > > We all know the disadvantages of such an approach (duplicate effort in > maintaining, diverging data, …). > > I worked, therefore, on producing a graphical representation from the OWL > ontology. I actually generate PlantUML, which then generates the diagram > using GraphViz. > > Gary was kind enough to review the initial results and thought we might > consider it for the future. > > > > I attach a couple of generated files. > > > > Quick notes: > > - The attached data is a DRAFT of an interim state. Do not use for any > serious purpose. Consider it only Proof of Concept. > - The generation is still a hack and not a very polished solution. So, > the distinction between “class” and “enumeration” (noted by “C” or “E” in a > circle in the diagram) is not very robust. Unfortunately, in OWL everything > is classes… > - The only arrows (relationships) depicted are: > - Solid lines with white triangle: the typical way to represent > “subclass of” > - Dotted lines with arrows: a class points to the class of an > element > - There is no information like “1:N” on purpose; it’s a little > confusing to have a class diagram also look like an entity-relationship > one. > - You can see the (deprecated) “Review” class in the upper right of > the diagram, not connected to anything. This will be fixed in the ontology. > - You may also notice a brand new “LicenseExpressionDRAFT” class, > abstracting away all details about licenses, operators, license list or > LicenseRef entries, etc. I felt this level of detail inside license > expressions confused the “SPDX-info” side of things. We probably can have a > separate diagram about license expressions, without confusing the “core” > classes and data model. > > > > May I please ask you to review the graphic, tell me whether it’s useful > and point out other information you would like to see included. > > If there are no major disadvantages, we will consider retiring the > (independent) “model” graphic. > > > > -- zvr > > > > Intel Deutschland GmbH > Registered Address: Am Campeon 10-12, 85579 Neubiberg, Germany > Tel: +49 89 99 8853-0, www.intel.de > Managing Directors: Christin Eisenschmid, Gary Kershaw > Chairperson of the Supervisory Board: Nicole Lau > Registered Office: Munich > Commercial Register: Amtsgericht Muenchen HRB 186928 > > > -=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#3867): https://lists.spdx.org/g/Spdx-tech/message/3867 Mute This Topic: https://lists.spdx.org/mt/73191667/21656 Group Owner: [email protected] Unsubscribe: https://lists.spdx.org/g/Spdx-tech/unsub [[email protected]] -=-=-=-=-=-=-=-=-=-=-=-
