Drupal EntityReference / References / Relation talk

Delivered on April 27th, 2013 at the Western New York Drupal Mini-Camp

Transcript

1. The Relation module: Because having one way of doing things just wouldn’t be Drupal.
2. SO YOU WANT TO RELATE SOME STUFF TO SOME OTHER STUFF? Easy!
3. WHICH MODULE SHOULD YOU USE? Well there’s ENTITY REFERENCE, which is very popular, and then there’s REFERENCES, which isn’t the same thing but similar, then there’s RELATION which is the most popular! Doesn’t ORGANIC GROUPS do this?
5. BREAK IT DOWN ENTITY REFERENCE - Probably RELATION - Specific Use Case REFERENCES - Legacy ORGANIC GROUPS - If you’re already...
6. ENTITYREFERENCE
7. ENTITYREFERENCE http://drupal.org/project/entityreference Lots of use and support (68,748 installs) Integration with all the toys (Views, Devel generate, Feeds and Migrate)
8. WHY ELSE? Lots of support from big commercial Drupal shops, IE: Drupal Commerce has added a lot of cool stuff (inline editor!). Out of the box comes with some nice widgets (select / radios & checkboxes / autocomplete)
10. WHY NOT? EntityReference is designed for 1-n relationships (one entity relates to many others). The relation lives on an entity, as a field, not truly in between entities. Not fieldable :(
11. IT’S A FIELD! While it’s possible to copy a reference field from one entity to another (Corresponding Entity Reference /cer) this is a duplication of data. Editing a reference edits the modified date on the entity, etc.
12. RELATION
13. RELATION http://drupal.org/project/relation Relations are entities, not fields! Since they’re entities, relations are fieldable. This is awesome.
14. FIELDABLE? Relations can therefore easily handle shared fields of data that’s owned by the relation entity itself.
15. IE JOHN has an ACCOUNT at BANK OF AMERICA with a balance of $100. ADAM is FRIENDS with JULIE and they met in high school.
16. WHY NOT JUST USE ECK? You could build something very similar to Reference using the Entity Construction Kit by creating an entity that has EntityReference fields... but...
17. IT WOULDN’T BE ABLE TO... • have different kinds of entities connected to a single endpoint • handle symmetrical relations (IE, one rule is fired for both ends of the relationship) • list siblings in views • support revisions
18. MULTIPLE TYPE PER ENDPOINT USER ADAM, NODE 123, and TAXONOMY TERM 5 are ALL THE THINGS.
20. SYMMETRICAL RELATIONS VINCE, PETER, and BETTY are SIBLINGS. in which the relation points in all directions, there’s no owner of the SIBLING relationship.
21. SO WHAT’S THE CATCH? The Relations UI is often ugly and weird for anyone but space robots and mad scientists. That’s a fixable problem, with time.
22. WIERD UI Ships with the “Relation Add Module” which is like a shopping cart for relating entities shown on a given page IE: not the use case of anyone in the real world ever.
23. REFERENCES
24. REFERENCES http://drupal.org/project/references Exists as a direct upgrade path for those users who were using the CCK node_reference and user_reference fields in D6 and wanted an equivalent in D7. Popular, but doomed.
25. REFERENCES
26. UPGRADE PATH Given where EntityReference is headed in Drupal 8, even the References folks are suggesting you migrate that way. A module (drush plugin) exists to do just that.
27. ORGANIC GROUPS http://drupal.org/project/og Is in this deck because Nick asked me to talk about it...
28. ORGANIC GROUPS
29. ORGANIC GROUPS Through OG’s concept of grouping content together for users who are members of these groups, it can be used as a mechanism to relate entities together... However...
30. ORGANIC GROUPS OG is massive and has a lot more going on than just linking things. Unless your project is already built around OG you probably don’t want to introduce it for the sake of relating things...
31. ...IN THE FUTURE EntityReference is in flippin’ CORE in Drupal 8:
32. CORE Since EntityReference is in core it’s the most future proof. That said, Relation’s got their D8 branch up...
33. PREDICTION / RECOMMENDATION Look for the things that Relation does better to be either be incorporated into EntityReference, or for Relation to start using parts of core EntityReference under the hood... So use ER until you can’t...
34. Adam White If you want these slides: www.upperrapids.ca/relation @adamwhite @upperrapids