JSON data to instance variable in Ruby - ruby-on-rails

Question

This is my ruby code / JSON File. Three functions required, I have implemented the first two but am having trouble with the third one. I have only recently started learning ruby - any simplified explanations/answers are much appreciated
class Company
attr_accessor :jobs
jobs = Array.new
## TODO: Implement this method to load the given JSON file into Ruby built-in data
## structures (hashes and arrays).
def self.load_json(filepath)
require 'json'
file = File.read(filepath)
data_hash = JSON.parse(file)
end
## TODO: This method should update the `jobs` property to an array of instances of
## class `Job`
def initialize(filepath)
# Load the json file and loop over the jobs to create an array of instance of `Job`
# Assign the `jobs` instance variable.
load_json(filepath)
data_hash.each { |jobs|
array_of_jobs.insert(jobs['name'])
}
end
## TODO: Impelement this method to return applicants from all jobs with a
## tag matching this keyword
def find_applicants(keyword)
# Use the `jobs` instance variable.
end
end
Below is the JSON file code I am supposed to retrieve the information from.
{
"jobs": [
{
"id": 1,
"title": "Software Developer",
"applicants": [
{
"id": 1,
"name": "Rich Hickey",
"tags": ["clojure", "java", "immutability", "datomic", "transducers"]
},
{
"id": 2,
"name": "Guido van Rossum",
"tags": ["python", "google", "bdfl", "drop-box"]
}
]
},
{
"id": 2,
"title": "Software Architect",
"applicants": [
{
"id": 42,
"name": "Rob Pike",
"tags": ["plan-9", "TUPE", "go", "google", "sawzall"]
},
{
"id": 2,
"name": "Guido van Rossum",
"tags": ["python", "google", "bdfl", "drop-box"]
},
{
"id": 1337,
"name": "Jeffrey Dean",
"tags": ["spanner", "BigTable", "MapReduce", "deep learning", "massive clusters"]
}
]
}
]
}

Answer 1

Code provided by you will not compile and approach used is not very convenient.
Steps you may follow to implement it:
First implement your models. May look like:
class Applicant
attr_accessor :id, :name, :tags
def initialize(id, name=nil, tags=nil)
#id = id
#name = name
#tags = tags
end
end
class Job
attr_accessor :id, :title, :applicants
def initialize(id, title=nil, applicants=nil)
#id = id
#title = title
#applicants = applicants
end
end
Then define your Company class that works with jobs
class Company
attr_accessor :jobs
def initialize(jobs)
#jobs = jobs
end
def find_applicants(keyword)
# Now you can iterate through jobs,
# job's applicants and finally applicant's tags
# like this
applicants = []
#jobs.each do |job|
job.applicants.each do |applicant|
applicant.tags.each do |tag|
if keyword.eql? tag
# ...
end
end
end
end
applicants
end
end
And then you can load data from Json file and construct proper objects:
require 'json'
class DataLoader
def load(filepath)
hash = JSON.parse(filepath)
construct(hash)
end
private
def validate(hash)
# validate your data here
end
def construct(hash)
validate(hash)
jobs = []
hash['jobs'].each do |job|
applicants = []
job['applicants'].each do |applicant|
applicants << Applicant.new(applicant['id'], applicant['name'], applicant['tags'])
end
jobs << Job.new(job['id'], job['title'], applicants)
end
jobs
end
end
And all together will look like:
tag = 'google'
data = DataLoader.new.load(File.read('data.json'))
company = Company.new(data)
applicants = company.find_applicants(tag)
puts "Applicants that have '#{tag}' in taglist"
applicants.each do |applicant|
puts " #{applicant.id}: #{applicant.name}"
end
#Applicants that have google in taglist
# 2: Guido van Rossum
# 42: Rob Pike

Answer 2

Here is a simple implementation of find_applicants. JSON objects can be iterated through like any other data structure.
Ideone example here.
def find_applicants(myJson, keyword)
names = []
myJson["jobs"].each do |job|
job["applicants"].each do |applicant|
tags = applicant["tags"]
if tags.include? keyword then
names << applicant["name"]
end
end
end
names
end