| [railML2] Wording of semantic constraints TT:015 and TT:016 [message #3407] |
Mon, 09 December 2024 16:33  |
Milan Wölke
Messages: 206
Registered: April 2007
|
Senior Member |
|
|
Hello all,
During the currently ongoing implementation of railVIVID 2 which will also include semantic validation as part of its validation feature, our developer came across the above semantic constraints TT:015 and TT:016.
TT:015 states:
Quote:At the first <ocpTT> of a <trainPart> that is not the first one of the <trainPartSequence>, the attribute @arrival is optional. If it is set anyway, then, for consistency reasons, the value of @arrival of the regarding <ocpTT> must be identical for both this <trainPart> and the preceding one.
TT:016 states:
Quote:At the last <ocpTT> of a <trainPart> that is not the last one of the <trainPartSequence>, the attribute @departure is optional. If it is set anyway, then, for consistency reasons, the value of @departure of the regarding <ocpTT> must be identical for both this <trainPart> and the subsequent one.
I was reviewing these constraints after complaints of our developer that these were hard to understand and I have to agree that if you dont already know what they are talking about, it is hard to understand the meaning.
What this is talking about is that if you encode a train that consists of more than one <trainPartSequence> element, then the first <ocpTT> of each referenced <trainPart> that is not the first <ocpTT> of the train needs to make sure that if an @arrival is specified (which it may not as it is optional in the case) that it matches the arrival given in the last <ocpTT> of the preceding <trainPart> of that train.
We have the following minor change of wording that we would hope could improve the clarity of the semantic constraints:
TT:015:
Quote:At the first <ocpTT> of non-initial <trainPart>s of a <trainPartSequence> of a <train>, the attribute @arrival is optional. If it is set anyway, then, for consistency reasons, the value of @arrival of the matching <ocpTT> must be identical for both this <trainPart> and the preceding one.
TT:016:
Quote:At the last <ocpTT> of continued <trainPart>s of a <trainPartSequence> of a <train>, the attribute @departure is optional. If it is set anyway, then, for consistency reasons, the value of @departure of the matching <ocpTT> must be identical for both this <trainPart> and the following one.
Does this help in understanding the semantic constraint. Do you, after all my writing understand what this is all about? If not, what did you understand? How would you formulate the constraint so that it is easily understood.
Thanks in advance for your help.
Best regards, Milan
Milan Hoffmann – Timetable schema coordinator
railML.org (Registry of Associations: VR 5750)
Altplauen 19h; 01187 Dresden; Germany www.railML.org
|
|
|
|
Members
Search
Help
Login
Home
