[SOLVED] HTTP binding and JSONPATH: unable to extract data

Setup, Configuration and Use Beginners
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1

Dear all,
I do not consider myself an experienced user of OpenHAB, but I am playing with it since a couple of years mainly by adapting samples taken from this same community or elsewhere on the web. I am now asking help because I am trying to extract an information that should be contained inside a JSON structure. I have the following line inside the .items file:

String Migrants "Migrants" {http="<[https://data2.unhcr.org/api/population/get?widget_id=74014&geo_id=656&sv_id=11&population_group=4797&year=latest:60000:JSONPATH($.data.0.individuals)]"}

And the following very elementary line on the sitemap:

Text item=Migrants

Well, actually in my specific case the information is a number, but given that at the moment I am not interested in any further elaboration I can also find acceptable to represent as a string. The issue is that on the sitemap I do not see any value. I am using OpenHAB 2.3 on a Raspberry Pi, and both the HTTP binding and JSONPATH transformation are obviously installed. I also made some tests on http://jsonpath.com/ and apparently the expression “$.data.0.individuals” seems to be correct.
I am pretty convinced that I made some stupid mistake due to my inexperience. Someone of you can help me? Thanks in advance!

All the best, Marco

2

Have you tried with Text item=Migrants label=“Somename [%d]”
or use [%s] for string?

3

Hi H102, thank for your answer.
With [%s] for string I can now see the entire JSON output, without any parsing. Or more precisely, I can see the very initial part of the JSON output, given that the remaining is truncated.
At this point I suspect that the issue is inside the JSONPATH expression…

From http://jsonpath.com/ I can see this output:

[
“20129”
]

My intention is, of course, to show that value (“20129”), as string or maybe further also as number.

Thank you again

4

OK, I found the solution: with JSONPATH($.data[0].individuals) is working now!
BTW, it is working also as a number with this expression:

Number Migrants "Migrants [%d]" {http="<[https://data2.unhcr.org/api/population/get?widget_id=74014&geo_id=656&sv_id=11&population_group=4797&year=latest:60000:JSONPATH($.data[0].individuals)]"}

Thank you! :slightly_smiling_face:

1 Like
5

Sorry but may I know what this API is out of curiosity?
I’m a sucker for this kind of data

6

It is an API managed by UNHCR, the Refugee Agency of United Nations that gives detailed statistics about refugee situations all over the world. You can find information here:

http://data.unhcr.org/wiki/index.php/API_Documentation.html

BTW, I am not directly involved in these issues, but the question of immigrations from the Mediterranean is very discussed in my country (Italy) as you probably know, and I want to keep myself informed with reliable data and not with the crap told by some politicians. As a matter of fact I am testing OpenHAB also for a function for which perhaps it was not created, but for which it could work well, i.e. as an “information aggregator”.
APIs can help a lot for this, but my next step will be with RSS feeds. I am going slowly, because I do not have so much spare time, and also because I am almost 58 years old: younger generations are much faster as regards the assimilation of these techniques!! :slight_smile: