HTTP binding - openHAB 3 version

Add-ons Bindings
#1

As some of you might know the http binding is still an openHAB 1-addon and will not be supported in the upcoming openHAB3. Therefore I developed a new openHAB 3-version. This is still work-in-progress, but I would like to here your thoughts (especially on missing or unclear features), bugs and everything related.

The documentation can be found on Github: (edited: binding included in distribution).http and the latest and greatest JAR is available at (edited; binding included in distribution).

You should be able to use the old http binding and the new one side-by-side, so no risk in trying out what is coming.

Edit: Updated link to 3.0.0. Newer version will not be compiled for 2.5.x

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#2

@J-N-K Thank you for all the hard work you do for OH and the community. :+1: Just wanted to let you know it does not go un-noticed. :smiley: Thanks again.

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#3

Well done, and thanks. Been wondering about the http1 binding.

Some things and items files examples would be great.
I use the http binding a bit, it’s great for when there’s no binding or mqtt bridge available.

It’s a pity with the move to openhab 2 that what used to be just configured as an item, now needs a thing then an item referencing the thing (mqttv2 is quite a pain for this). No fault of yours of course

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#4

great, Thanks. I’m only using the http binding in my rules as an action. Is it possible to use this one also in a rule? The extension feature looks very interesting, because this is one feature I miss in the v1 binding

#5

As mentioned in OP this version should work side-by-side with version 1 so give it a try and post back the results. If there’s an issue it would be good for @J-N-K to know so he can look into it.

#6

no what I meant was that e.g. I want to make a get request with some authorization, headers etc. In this v2 version I see that you can define them in the things file. However I see no option to use this in a rule as an action. The v1 version can be used as an action in the rule, however there are the limitations with the header, atuh etc.
That’s why I asked if this v2 version can be used within a rule with the additionals extensions listed in the markdown

#7

Ah, I see what you mean now. :upside_down_face:

Give it a try and see if it works as expected. If not maybe a change or feature can be added. :wink:

#8

Can you give an example how that looks? I can’t find documentation in the http binding about actions.

#9

I think @NoneWhereTo refers to this:

I think the “Actions” are actually part of the OH basis and not of the Binding, which can lead to some confusion.

#10

OH2 bindings can offer Actions for use in rules, these are “got hold of” by using a getActions(http, some params) method. I suspect this is not yet existing for the new binding.

#11

@J-N-K how can you get a value from a json array?
In http1 I had: [0].name
I have tried it this way in the new binding: JSONPATH:$[0].name

But I get an exception…

#12

Thanks for your engagement. Upfront, I haven’t validated that yet, but the old binding had a nuisance that if the target was unreachable, it was spitting errors with an error level log. That was very annoying when it’s every n seconds and it was not a (binding) error in fact but server unreachable is a perfectly (well :wink:) normal condition that should not result in error logging.
Please don’t repeat implementing that behavior in your new version.

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#13

Can you please show the server response and the exception?

#14

The question is how this should be handled. UNDEF or just ignore the error?

1 Like
#15

Sure. Here is the exception:

2020-07-09 21:40:09.798 [WARN ] [mmon.WrappedScheduledExecutorService] - Scheduled runnable ended with an exception: 

java.lang.IllegalArgumentException: Illegal character in scheme name at index 0: "https://api.github.com/repos/arendst/Tasmota/tags"

	at java.net.URI.create(URI.java:852) ~[?:1.8.0_222]

	at org.eclipse.jetty.client.HttpClient.newRequest(HttpClient.java:442) ~[?:?]

	at org.openhab.binding.http.internal.http.RefreshingUrlCache.refresh(RefreshingUrlCache.java:79) ~[?:?]

	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) ~[?:1.8.0_222]

	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308) ~[?:1.8.0_222]

	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180) ~[?:1.8.0_222]

	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294) ~[?:1.8.0_222]

	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:1.8.0_222]

	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:1.8.0_222]

	at java.lang.Thread.run(Thread.java:748) [?:1.8.0_222]

Caused by: java.net.URISyntaxException: Illegal character in scheme name at index 0: "https://api.github.com/repos/arendst/Tasmota/tags"

	at java.net.URI$Parser.fail(URI.java:2848) ~[?:1.8.0_222]

	at java.net.URI$Parser.checkChars(URI.java:3021) ~[?:1.8.0_222]

	at java.net.URI$Parser.checkChar(URI.java:3031) ~[?:1.8.0_222]

	at java.net.URI$Parser.parse(URI.java:3047) ~[?:1.8.0_222]

	at java.net.URI.<init>(URI.java:588) ~[?:1.8.0_222]

	at java.net.URI.create(URI.java:850) ~[?:1.8.0_222]

	... 9 more

Ps.: My bad, I had a look at the exception again and the problem was in the base url, I forgot to delete the quotation marks, it works now!

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#16

Would you post your example (in case you use text file definition)?

#17

INFO level logging ?
Ideally on state changes only (server gone between last and current request + when server came back)

#18

I’m using PaperUI. Anyway the config is really straightforward.
Define the BaseURL at thing level and add state transform for a channel as you would do in MQTT2 binding.
So state transform should look like this (assuming a json input):

JSONPATH:$[0].name
#19

Thanks for bringing that up!
Yes it was really annoying and it not even showed these errors between the specified poll intervals but every few seconds…
@J-N-K
I think an UNDEF state for channels on a Thing is great for showing unreachable hosts. Maybe also use ThingStatus to represent availability on a Thing level?

#20

For anyone who wants to start off using/migrating textual config, here is a very simple example that works for me:


Thing http:url:exchangerate "USD-EUR Exchange Rate" [ baseURL="https://api.exchangeratesapi.io/latest?symbols=USD", refresh=3600] {
    Channels:
        Type number : USDEUR "Exchange Rate" [ stateTransformation="JSONPATH:$.rates.USD" ]
}

Item:
Number ExchangeRateEURUSD  "EUR - USD [%.3f]"                  <exchangerate>          (gAll)  {channel="http:url:exchangerate:USDEUR"}
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