How to parse JSON response in Ruby

Question

The end goal for this is to be part of a chatbot that returns an airport's weather.

Using import.io, I built an endpoint to query the weather service I'd which provides this response:

{"extractorData"=>
  {"url"=>
    "https://www.aviationweather.gov/metar/data?ids=kokb&format=decoded&hours=0&taf=off&layout=on&date=0",
   "resourceId"=>"66ca907842aabb6b08b8bc12049ad533",
   "data"=>
    [{"group"=>
       [{"Timestamp"=>[{"text"=>"Data at: 2135 UTC 12 Dec 2016"}],
         "Airport"=>[{"text"=>"KOKB (Oceanside Muni, CA, US)"}],
         "FullText"=>
          [{"text"=>
             "KOKB 122052Z AUTO 24008KT 10SM CLR 18/13 A3006 RMK AO2 SLP179 T01780133 58021"}],
         "Temperature"=>[{"text"=>"17.8°C ( 64°F)"}],
         "Dewpoint"=>[{"text"=>"13.3°C ( 56°F) [RH = 75%]"}],
         "Pressure"=>
          [{"text"=>
             "30.06 inches Hg (1018.0 mb) [Sea level pressure: 1017.9 mb]"}],
         "Winds"=>
          [{"text"=>"from the WSW (240 degrees) at 9 MPH (8 knots; 4.1 m/s)"}],
         "Visibility"=>[{"text"=>"10 or more sm (16+ km)"}],
         "Ceiling"=>[{"text"=>"at least 12,000 feet AGL"}],
         "Clouds"=>[{"text"=>"sky clear below 12,000 feet AGL"}]}]}]},
 "pageData"=>
  {"resourceId"=>"66ca907842aabb6b08b8bc12049ad533",
   "statusCode"=>200,
   "timestamp"=>1481578559306},
 "url"=>
  "https://www.aviationweather.gov/metar/data?ids=kokb&format=decoded&hours=0&taf=off&layout=on&date=0",
 "runtimeConfigId"=>"2ddb288f-9e57-4b58-a690-1cd409f9edd3",
 "timestamp"=>1481579246454,
 "sequenceNumber"=>-1}

I seem to be running into two issues. How do I:

pull each field and write it into its own variable
ignore the "text" modifier in the response.

Let's see, did you try `JSON.parse` from http://ruby-doc.org/stdlib-2.0.0/libdoc/json/rdoc/JSON.html ? — Eric Duminil, Dec 12 '16 at 22:27
Welcome to Stack Overflow. Please read "[ask]" including the linked pages and "[mcve]". When asking it really helps us if you show us the minimal code necessary to demonstrate the problem you're having. Without that it looks like you haven't tried to solve the problem, and that you want us to write it for you. Also, reduce the sample JSON to the bare minimum necessary to demonstrate the problem you're having. — the Tin Man, Dec 12 '16 at 22:27
http://stackoverflow.com/questions/5410682/parsing-a-json-string-in-ruby?rq=1 would be good to read also. — the Tin Man, Dec 12 '16 at 22:42

score 14 · Answer 1 · answered Dec 13 '16 at 04:32

14

If you're getting a response object, you might want to do something like

parsed_json = JSON.parse(response.body)

Then you can do things like parsed_json[:some_field]

answered Dec 13 '16 at 04:32

ithinkiknowruby

366
1
9

the Tin Man · Answer 2 · 2016-12-12T22:37:31.150

The simple answer is:

require 'json'

foo = JSON['{"a":1}']
foo # => {"a"=>1}

JSON is smart enough to look at the parameter and, based on whether it's a string or an Array or Hash, parse it or serialize it. In the above case it parsed it back into a Hash.

From that point it takes normal Ruby to dive into the hash you got back and access particular values:

foo = JSON['{"a":1, "b":[{"c":3}]}']
foo # => {"a"=>1, "b"=>[{"c"=>3}]}
foo['b'][0]['c'] # => 3

How to walk through a hash is covered extensively on the internet and here on Stack Overflow, so search around and see what you can find.

How to parse JSON response in Ruby

2 Answers2