No transformation service available

[sipvoip]

Found an issue when migrating to openHAB 2, it looks like transformation are not working at least with the serial binding. I think it has to do with 1x compatibility layer because it works fine in 1.8.3.

Item:
Number Septic_Level_Sensor {serial="/dev/ttyPort3,REGEX(.?([0-9]+).)"}

Seeing:
2017-02-25 16:28:10.896 [ERROR] [binding.serial.internal.SerialDevice] - No transformation service available!

I have REGEX transform installed according to paper.

[marekhalmo]

Hello, i have the same issue.. Any ideas on why this is a problem?

[marekhalmo]

I have been looking in to this issue.
@csowada has made the change in the code that uses the service instead of pattern matcher. Maybee he could help
@csowada could you please explain how the transformation service is set during startup?

[csowada]

So I have looked into this issue. There is simply no compat delegator for the transformation service. But there is a Helper Class that should work without declarative services.

https://github.com/openhab/openhab1-addons/blob/1.8/bundles/core/org.openhab.core.transform/src/main/java/org/openhab/core/transform/TransformationHelper.java

[marekhalmo]

Hello,
thank you for the super fast response.
I tried the TransformationHelper but it still does not work
The error is: "Cannot get service reference for transformation service of type REGEX"

[marekhalmo]

I also have been looking in to this and it seems that this is OH 1.x vs OH2 compatibility issue.
There are interfaces of Transformation service with the same name in both projects but they have a different package:

org.eclipse.smarthome.core.transform.TransformationService org.openhab.core.transform.TransformationService

So the serial binding with regex transformation will work for OH1 but won't for OH2
I can't change the transformation service to OH2 because OH1 addons project does not have (and will never have) a OH2 dependency to the required.

What to do now? Is it necessary to migrate the serial binding to OH2?

[csowada]

Have you checked that a TransformationService is available from your Karaf console? I think the TransformationHelper class is the best solution.

[marekhalmo]

It won't ever be possible. Th interface types specified in osgi xml don't match..

[marekhalmo]

The RegexTransformationService for OH2 implements interface org.eclipse.smarthome.core.transform.TransformationService. The RegexTransformationService for OH2 specified in serialBinding requires implementation of interface org.openhab.core.transform.TransformationService.

Because there is no way of including org.eclipse.smarthome.core.transform.TransformationService in the OH1 addons and OH2 will never have org.openhab.core.transform.TransformationService regex implementation, you can't possibly have OH2 binding.

There are multiple solution to this.
a) Migrate serial binding to OH2
b) Implement logic to SerialBinding that if you don't provide TransformationService, it will use a basic regex as in the original commit. The basic regex could be wrapped in a custom TransformationService implementation

I guess i would go for b) just to keep the code of serial binding at the same place for OH1/2.. Should i do this?

[marekhalmo]

Hm.. i also found out that the previous implementation with pattern matching was better because it could handle fast serial port updates.
For example imagine you wanted to parse temperature update in format
Tmp: 10deg

If the device sends the temperature twice fast you get a partial string e.g.
Tmp: 10deg\r\nTmp: 11deg\r\n

With the old code you will match both 10deg and 11deg.. -> Values fine.
If you use the new code you will only match the first string and the rest will be ignored.
E.g. > You get 10deg and ignore the correct value 11deg coming second.

It is also very unpredictable so hard to find the issue..

You can also in theory have a partial data (e.g. Tmp: 1) which will ignore everything completely.. So without definition of next data separator the serial binding is kinda useless

[sipvoip]

So can we move back to the old way? I have some fast devices so I also run into this issue. How much time do you think it would take to fix the serial binding for openHAB2?

[marekhalmo]

Hm... i have a partial fix done locally but it just fixes the issue with TransactionService not available in OH2.

I can create a pull request tomorrow but it won't fix the rapid command issue.

Now what?

[marekhalmo]

@sipvoip are you experiencing message drops when using serial binding with regex and OH1?

[marekhalmo]

Ok i have been thinking about this for a while and i think i will have a good solution tomorrow. I will create a fix and a pull request asap (i also need this be in release soon)

The fix will be following:

1. i will take code from OH2 regex transformation and adapt it to form of old code
2. I will modify md file to comply with the changes

This way the code will be able to parse multiple commands as the old version and won't depend on the transformation service and OH version. It also won't break compability with regex syntax. I think that the transformations are meant to be used in rules only so there should be no issue from architectural point of view.

Binding depending on another component that has to be installed manually can only lead to confusion

[marekhalmo]

Implemented, just need to wait for the this pull request to be merged so i can create a branch for the fix.

It will work according to the new RegexTransformationService described here

I will let you know when there will be official branch..

[sipvoip]

Is there a .jar I can try?

[marekhalmo]

not yet

[marekhalmo]

I still have a bit trouble with the repeating patterns (or fast commands)..

The RegexTransformation uses ^REGEX_PATTERN$ with DOTAL to find the group.. that is fine if you want to extract number from simple string like "Temp: 10\n"... but if you get two responses it looks like "Temp: 10\nTemp: 10\n".. the pattern match just wont match the string because the ^ and $ and DOTAL means that the whole string has to be matched in order to get the group... so in that case the whole received string gets ignored.

Could anyone help with this? I would post sniplets of code so you could see what's going on

[9037568]

What does DOTAL mean? Never heard of it before.

If you're implementing a new/pseudo transformation service, you should be able to use whatever pattern works; no need to stick with the one you're quoting, is there?

[marekhalmo]

A great explanation can be found (here) [ http://docs.oracle.com/javase/tutorial/essential/regex/pattern.html] ...

The new REGEX matcher has to comply with the existing functionality so we don't break the config files of everybody that uses it.

[9037568]

Yes, but remember it's the output from the transformation that matters. How that output is produced doesn't.

[marekhalmo]

Hello guys, i committed the full patch for this here (sorry for the double linking)

A jar for everybody to test can be found here
Just put it in your adons folder and it should work

[marekhalmo]

Hello, anyone tried the provided JAR?

[csowada]

No, sorry but I not use this binding anymore.

[marekhalmo]

Okay.. the fix was merged.. you can expect this working in next release... until the you can use the provided jar...

Thanks everyone for your support.

[kaikreuzer]

So if I get it right, this issue here can be closed. Thanks @marekhalmo for dealing with it in the serial binding!

[marekhalmo]

@kaikreuzer glad i could help :)