Implementing this will be possible with the nearly-ready dataprovider: https://cgit.freedesktop.org/libreoffice/core/tree/sc/source/ui/dataprovider

Nice, I see very recents commits.

As extra motivation, I was trying to extract Bitcoin prices from this API, 

=SUBSTITUTE(WEBSERVICE("https://min-api.cryptocompare.com/data/pricemulti?fsyms=BTC,ETH,LTC&tsyms=USD"), """:{""USD""", "")

The SUBSTITUTE above is just prep. After that, to get at a value, I came up with a formula looks like this:

=VALUE(MID(A1, SEARCH("(?<=BTC:)\d", A1), FIND("}", A1, SEARCH("(?<=BTC:)\d", A1)) - SEARCH("(?<=BTC:)\d", A1)))

A week later, that thing above looks more cryptic than elliptic curve cryptography :) I have no idea what it does at a glance and why it's so repetitive.

LibreOffice uses liborcus as an mandatory external lib, and Orcus provides json support. Thus this filer may not be hard to implement.

*** Bug 109073 has been marked as a duplicate of this bug. ***

(In reply to Dan Dascalescu from comment #5)
> 4 years later, any progress?

Yes, data provider got a UI: https://libreoffice-dataproviders.blogspot.com/2021/08/data-providers.html

But: "The external data currently supported are CSV , HTML , XML and Base". So what Kevin said in comment 3 is still relevant.

Still really waiting on FILTERJSON() function. Please add it to LibreOffice! PLEASE GOD!

As in many cases, web-pages to import are in JSON format, it will be really useful.

I started to parse this JSON using this formula :
=PARSEJSON(A1, "outputs.monthly.fixed.get(1).E_m") . I get : 31.29
For month 2 I used : 
=PARSEJSON(A1, "outputs.monthly.fixed.get(2).E_m") . I get : 71.38
untill I get to month 12 :
=PARSEJSON(A1, "outputs.monthly.fixed.get(12).E_m") . and there I get no such node found.

It seems that after 11 it's bugging

JSON file :

{"inputs":{"location":{"latitude":50.0,"longitude":8.0,"elevation":104.0},"meteo_data":{"radiation_db":"PVGIS-SARAH","meteo_db":"ERA-Interim","year_min":2005,"year_max":2016,"use_horizon":true,"horizon_db":"DEM-calculated"},"mounting_system":{"fixed":{"slope":{"value":0,"optimal":false},"azimuth":{"value":0,"optimal":false},"type":"free-standing"}},"pv_module":{"technology":"c-Si","peak_power":1.0,"system_loss":14.0},"economic_data":{"system_cost":null,"interest":null,"lifetime":null}},"outputs":{"monthly":{"fixed":[{"month":1,"E_d":0.59,"E_m":18.36,"H(i)_d":0.8,"H(i)_m":24.67,"SD_m":2.13},{"month":2,"E_d":1.12,"E_m":31.29,"H(i)_d":1.41,"H(i)_m":39.36,"SD_m":6.45},{"month":3,"E_d":2.3,"E_m":71.38,"H(i)_d":2.82,"H(i)_m":87.54,"SD_m":11.19},{"month":4,"E_d":3.68,"E_m":110.26,"H(i)_d":4.57,"H(i)_m":137.06,"SD_m":15.67},{"month":5,"E_d":4.04,"E_m":125.13,"H(i)_d":5.08,"H(i)_m":157.51,"SD_m":17.94},{"month":6,"E_d":4.44,"E_m":133.16,"H(i)_d":5.71,"H(i)_m":171.22,"SD_m":13.81},{"month":7,"E_d":4.27,"E_m":132.5,"H(i)_d":5.57,"H(i)_m":172.78,"SD_m":11.89},{"month":8,"E_d":3.65,"E_m":113.22,"H(i)_d":4.72,"H(i)_m":146.37,"SD_m":7.96},{"month":9,"E_d":2.73,"E_m":81.93,"H(i)_d":3.49,"H(i)_m":104.71,"SD_m":7.8},{"month":10,"E_d":1.58,"E_m":48.97,"H(i)_d":2.02,"H(i)_m":62.65,"SD_m":6.44},{"month":11,"E_d":0.7,"E_m":21.12,"H(i)_d":0.95,"H(i)_m":28.45,"SD_m":2.53},{"month":12,"E_d":0.46,"E_m":14.27,"H(i)_d":0.65,"H(i)_m":20.04,"SD_m":1.24}]},"totals":{"fixed":{"E_d":2.47,"E_m":75.13,"E_y":901.57,"H(i)_d":3.16,"H(i)_m":96.03,"H(i)_y":1152.37,"SD_m":2.73,"SD_y":32.7,"l_aoi":-4.28,"l_spec":"1.45","l_tg":-6.31,"l_total":-21.76}}},"meta":{"inputs":{"location":{"description":"Selected location","variables":{"latitude":{"description":"Latitude","units":"decimal degree"},"longitude":{"description":"Longitude","units":"decimal degree"},"elevation":{"description":"Elevation","units":"m"}}},"meteo_data":{"description":"Sources of meteorological data","variables":{"radiation_db":{"description":"Solar radiation database"},"meteo_db":{"description":"Database used for meteorological variables other than solar radiation"},"year_min":{"description":"First year of the calculations"},"year_max":{"description":"Last year of the calculations"},"use_horizon":{"description":"Include horizon shadows"},"horizon_db":{"description":"Source of horizon data"}}},"mounting_system":{"description":"Mounting system","choices":"fixed, vertical_axis, inclined_axis, two_axis","fields":{"slope":{"description":"Inclination angle from the horizontal plane","units":"degree"},"azimuth":{"description":"Orientation (azimuth) angle of the (fixed) PV system (0 = S, 90 = W, -90 = E)","units":"degree"}}},"pv_module":{"description":"PV module parameters","variables":{"technology":{"description":"PV technology"},"peak_power":{"description":"Nominal (peak) power of the PV module","units":"kW"},"system_loss":{"description":"Sum of system losses","units":"%"}}},"economic_data":{"description":"Economic inputs","variables":{"system_cost":{"description":"Total cost of the PV system","units":"user-defined currency"},"interest":{"description":"Annual interest","units":"%/y"},"lifetime":{"description":"Expected lifetime of the PV system","units":"y"}}}},"outputs":{"monthly":{"type":"time series","timestamp":"monthly averages","variables":{"E_d":{"description":"Average daily energy production from the given system","units":"kWh/d"},"E_m":{"description":"Average monthly energy production from the given system","units":"kWh/mo"},"H(i)_d":{"description":"Average daily sum of global irradiation per square meter received by the modules of the given system","units":"kWh/m2/d"},"H(i)_m":{"description":"Average monthly sum of global irradiation per square meter received by the modules of the given system","units":"kWh/m2/mo"},"SD_m":{"description":"Standard deviation of the monthly energy production due to year-to-year variation","units":"kWh"}}},"totals":{"type":"time series totals","variables":{"E_d":{"description":"Average daily energy production from the given system","units":"kWh/d"},"E_m":{"description":"Average monthly energy production from the given system","units":"kWh/mo"},"E_y":{"description":"Average annual energy production from the given system","units":"kWh/y"},"H(i)_d":{"description":"Average daily sum of global irradiation per square meter received by the modules of the given system","units":"kWh/m2/d"},"H(i)_m":{"description":"Average monthly sum of global irradiation per square meter received by the modules of the given system","units":"kWh/m2/mo"},"H(i)_y":{"description":"Average annual sum of global irradiation per square meter received by the modules of the given system","units":"kWh/m2/y"},"SD_m":{"description":"Standard deviation of the monthly energy production due to year-to-year variation","units":"kWh"},"SD_y":{"description":"Standard deviation of the annual energy production due to year-to-year variation","units":"kWh"},"l_aoi":{"description":"Angle of incidence loss","units":"%"},"l_spec":{"description":"Spectral loss","units":"%"},"l_tg":{"description":"Temperature and irradiance loss","units":"%"},"l_total":{"description":"Total loss","units":"%"}}}}}}

FYI, I just integrated orcus version 0.20.0 into the build, and one thing that's new is the ability to extract JSON subtree:

https://orcus.readthedocs.io/en/latest/overview/json/subtree.html

Perhaps this will be helpful when implementing this feature or something similar.

FYI, Calc will be able to directly open JSON files starting with 26.2.  See

https://wiki.documentfoundation.org/ReleaseNotes/26.2#Generic_XML_and_JSON_mapping_to_Calc

Perhaps we can consider that a solution to this issue?

(In reply to Kohei Yoshida from comment #11)
> FYI, Calc will be able to directly open JSON files starting with 26.2.  See
> 
> https://wiki.documentfoundation.org/ReleaseNotes/26.
> 2#Generic_XML_and_JSON_mapping_to_Calc
> 
> Perhaps we can consider that a solution to this issue?

Dan: are you happy with this?

Tested with a couple of files from https://sample.json-format.com/

employees_10KB.json (5 level)
employees-10-level_100MB.json

It works:
- opening directly the files.
- Menu>Sheets>Insert sheet from file

But not with
Menu>Sheet>External Links.
Menu>Data>Data Provider.

Opened an enhancement bug for this last.

tdf#168860 - Allow the ability to link to JSON files with Menu>Sheet>External Links and Menu>Data>Data Provider.

Let's call it fixed since the original submitter is no longer responsive & I believe this is now addressed.

It's definitely not fixed. We need something like the FILTERXML function but FILTERJSON instead. It's crazy that we can directly process XML content (which is a format quickly disappearing from the Internet) but not JSON (which is probably the most popular data interchange format online now).

Being able to open JSON files is definitely not the same as being able to import JSON data within a cell/sheet. Tons of use case, like importing currencies or stock market data, calling online APIs, etc.