Should I start with OpenHAB 3 now?

[rlkoshak (Rich Koshak)]

I think there is more documentation than you think at

• Introduction | openHAB
• Getting Started with OH3: rewriting the tutorial - 1. Introduction
• Building Pages in the OH3 UI: documentation draft (1/3)
• Search results for 'wiki oh3 getting started' - openHAB Community
• OH 3 Examples: How to boot strap the state of an Item
• OH 3 Examples: Writing and using JavaScript Libraries in MainUI created Rules

I think most of these are slated for inclusion in the official docs. Also, look at the PRs in the openhab-webui repo and there is a ton of great low level info for how to really customize pages and such.

Also, the vast majority of knowledge that you already possess and the vast majority of the existing OH 2 docs are still applicable.

But even at this point OH 3 is somewhat of a moving target with significant changes and new features being added almost daily. To keep up you need to be upgrading at least once a week. And sometimes those upgrades break things. And we would ask that if you do run OH 3 to please go to the links above and help us with the contents and to file issues.

@tophee

Could someone provide an indication what how big the differences between v3 and v2 are in practice?

That’s hard to answer and it largely depends on how you want to use OH 3. Do you want to continue doing stuff the same way you’ve done it in OH 2 on OH 3? If so the differences are pretty minor. PaperUI and HABmin are replaced with MainUI (which will have lots more options). There are some minor changes in rules and now JavaScript and Blockly (graphical programming of rules, similar to Scratch) is supported out of the box with an add-on for Groovy and another one for Jython on the way.

However, if you want to go all in for OH 3 the changes are quite significant. Now pretty much everything except for persistence policy files can be done through the UI, and the UI has lots of features that make working in much better and more efficient than PaperUI.

There is a new emphasis on the semantic model for your Items. If you spend the time building the model than MainUI will build most of your user’s interface for you.

Or if you don’t like the generated one you can build your own pages with all sorts of controls that were missing from sitemaps including stuff like the ability to enter text, date time pickers, etc.

Rules can be enabled, disabled, and call each other. You can import libraries into your rules (not Rules DSL).

Those are just a few of the new features and improvements.

@buschif4

As you mentioned there are a lot of documentation examples available for OH2 which are not available for OH3.

Unless those examples are based primarily on PaperUI, they still apply in OH 3 with only very minor changes (maybe).

@anonymous.one

as doco was for 1.8.x and some was for 2.x

The changes between OH 1.8 and OH 2.0 were greater than those for OH 3.

@anonymous.one

If I were brand new and asking for which version to go with, I would say go with OH 3; but read through how things/items and the various bindings work as most of what I have read through seems to be the same as OH 2.

Correct. And if you primarily use text based configs all that stuff applies as well. You could, if you wanted to, ignore all the new stuff and use OH 3 pretty much the same as you did in OH 2. That’s the primary reason why I push back just a little on the “there are no docs” arguments. There really are because the OH 2 stuff still mostly applies. The only things where docs are somewhat missing is for the stuff that’s new in OH 3 (Pages, having a UI to build the model, a working UI for rules, etc).

Having said all that, I’ll join the chorus. I’d recommend getting started or, if you haven’t invested too much in OH 2 yet moving to OH 3 now.