How to parse xml and send telegram message if too high?

[timo12357 (Timo)]

@JustinG

Check your transform definition, I think the problem is probably the position of that first ( which, if you’re putting it in the channel transform slot should be after the XPATH:

`XPATH:(//BsWfs:ParameterValue)[last()]/text()`

Unfortunately neithef this seems to work:

</wfs:FeatureCollection>
' with function 'XPATH:(//BsWfs:ParameterValue)[last()]/text()' and format '%s'
2023-08-29 10:54:28.587 [WARN ] [.profiles.XPathTransformationProfile] - Could not transform state '<?xml version="1.0" encoding="UTF-8"?>
<wfs:FeatureCollection
  timeStamp="2023-08-29T07:39:27Z"

[rlkoshak (Rich Koshak)]

I opened the URL you posted in the first post on this page. The XML you posted in the “Output looks like this” is incomplete. Copying the raw XML into an Xpath tester shows the following Xpaths to work to extract.

.//wfs:FeatureCollection/wfs:member/BsWfs:BsWfsElement/BsWfs:ParameterValue
//wfs:FeatureCollection/wfs:member/BsWfs:BsWfsElement/BsWfs:ParameterValue
//BsWfs:ParameterValue
//BsWfs:ParameterValue[last()]
//BsWfs:ParameterValue[last()][text()]
//(BsWfs:ParameterValue)[last()][text()]
//(BsWfs:ParameterValue)[last()]/text()

Note that not all of the above have the same meaning for Xpath, but given the XML produced by the URL right now, these all work.

Now, loaded with some options to try, if you are using a Profile as @JustinG demonstrates in post #18, the XPATH: part is understood. Since you selected “XPATH” from the list it already knows what transform you are using. So just put the XPATH string into the "XPATH Expression field without the XPATH: in front of it.

If you were using this in the HTTP binding’s Channel Config (which is my recommendation) you would still need to put the XPATH: in front of the expression because the Channel config does not have a selection widget to tell OH which transformation you want to use.

Also note that the XPATH: syntax with the : is unique to the HTTP and MQTT bindings. Other bindings and in the state description pattern/Item labels you’d use parens.

[JustinG]

OK, I’ve done some testing. The problem is that this xml uses nodes with the full namespace:local-name syntax, and the colon inbetween the namespace and local node name is breaking either the UI’s handling of the string before passing it to the transform or the transform, itself. I’m not sure yet which it is. I suspect the problem is with the actual transform because the issue happens both with the Profile without the "XPATH:transform...." and the channel definition with it.

I’ve test this alternate XPath that bypasses the namespace part of the node names and can verify that it works:

(//*[local-name() = 'ParameterValue'])[last()]/text()

Profile version:

Http Channel version:

Edit:
The Transform binding doc does not say that you can’t use namespace:local-name but it does have several advanced examples that use [local-name()='xxx'] so I wonder if this is a known issue already…

[rlkoshak (Rich Koshak)]

XML is such a pain.

[timo12357 (Timo)]

Thank you fine gentlemen for the help! I now have an elegant sea water level warning system to keep me from losing more robomowers.