Extract Data from a JSON (Ruby)

data_extractor.rb

require 'active_support/core_ext/hash'

# Input: 'extra:[1:main:[5:provider]]'
# Output: ['extra', 1, 'main', 5, 'provider']
def macro_key_parser(str, keys = [])
  first_key = str
  first_key, second_key = str.split(':', 2) if first_key[0] != '['
  if first_key[0] != '['
    keys << first_key.strip
    macro_key_parser(second_key, keys)
  else
    arr_index, first_key = first_key[1...(first_key.length-1)].split(':', 2)
    keys << arr_index.strip.to_i
    macro_key_parser(first_key, keys)
  end
  return keys
rescue
  str.split(':')
end

# ================== Example ================== # 

example = {
  "data": {
    "match_id": 137046,
    "league_id": 237,
    "match_statistics": [
      {
        "team_id": 2509,
        "team_name": "Liverpool FC"
      },
      {
        "team_id": 2589,
        "team_name": "Leeds United FC"
      }
    ]
  }
}
  
# To get the team_name 'Leeds United FC'

digger = macro_key_parser("data:match_statistics:[1:team_name]", keys = [])
example.with_indifferent_access.dig(*digger)

# To get the team_name 'Liverpool FC'

digger = macro_key_parser("data:match_statistics:[0:team_name]", keys = [])
example.with_indifferent_access.dig(*digger)

# Explanation of the method `macro_key_parser(str, keys = [])`

# A Json data may contain hashes and inside hashes may contain arrays. or vice versa. 
# if we have hash inside hash, to access the inner hash, we'll use "outer_hash_key:inner_hash_key" 
# From the example json above, `data:match_statistics` will return an array by the method. 
# if any hash contains array, that means the array has 1 or 1+ elements. To access the array element, we'll use "hash_key:[array_element_index]"
# From the example json above, `data:match_statistics:[0]` will return a hash. 
# if any array contains hash, we'll use "[array_element_index:hash_key]"
# From the example json above, `data:match_statistics:[0:team_name]` will return a string.