Fetch under one key ruby - ruby

Question

I have this json:
{"user"=>
{"name"=>"Lebron James",
"email"=>"lebron.james#gmial.com",
"time_zone"=>"America/Chicago",
"contact"=>
[{"id"=>"PO0JGV7",
"type"=>"email_contact_method_reference",
"summary"=>"Default",
"self"=>
"https://pagerduty.com/users/000000/contact/000000",
"html_url"=>nil},
{"id"=>"000000",
"type"=>"phone_contact_method_reference",
"summary"=>"Mobile",
"self"=>
"https://pagerduty.com/users/000000/contact/000000",
"html_url"=>nil},
{"id"=>"000000",
"type"=>"push_notification_contact_method_reference",
"summary"=>"XT1096",
"self"=>
"https://api.pagerduty.com/users/000000/contact/000000",
"html_url"=>nil},
{"id"=>"000000",
"type"=>"sms_contact_method_reference",
"summary"=>"Mobile",
"self"=>
"https://pagerduty.com/users/000000/methods/000000",
"html_url"=>nil}],
I want to be able to retrieve the values of the self keys, but only the ones that has "type" => "email_contact_method_reference" and "summary"=>"Mobile". This is what I thought would work.
phone = File.open("employee_phone_api.txt", "w+")
jdoc.fetch("user").fetch("contact_methods").each do |contact|
if contact["type"] == "email_contact_method_reference" and contact["summary"] == "Mobile"
phone.puts contact["self"]
else
end
end
Thoughts? And/or suggestions?

Answer 1

No need to use #each, as there are more expressive ways of handling this problem. As with many Ruby problems, you want to get an Array and then transform it. In this case, you want to select certain contacts and then pull out particular values.
Your sample hash has a "contact" key but not a "contact_methods" key. I'm using "contact" for my example. Also, your sample contains no objects that meet the criteria, so I'm modifying it to include one.
First we get an Array of all the contacts:
contacts = jdoc.fetch("user").fetch("contact")
Then we filter them to the desired type using Enumerable#select, which results in an Array of a single Hash object:
email_contacts = contacts.select { |contact| contact['type'] == 'email_contact_method_reference' && contact['summary'] == 'Mobile' }
#=> [{"id"=>"PO0JGV7", "type"=>"email_contact_method_reference", "summary"=>"Mobile", "self"=>"https://pagerduty.com/users/000000/contact/000000", "html_url"=>nil}]
Next we map out just the information we want:
urls = email_contacts.map { |contact| contact['self'] }
This results in urls being assigned an Array of a single string:
#=> ["https://pagerduty.com/users/000000/contact/000000"]
In the real world, you will want to have a method that accepts arguments, making the logic flexible. You might do something like this:
def fetch_urls(doc, type, summary)
doc.fetch("user").fetch("contact")
.select { |contact| contact['type'] == type && contact['summary'] == summary }
.map { |contact| contact['self'] }
end
>> fetch_urls(jdoc, 'email_contact_method_reference', 'Mobile')
#=> ["https://pagerduty.com/users/000000/contact/000000"]
Now that you have a working method, you can use it in your file writer:
>> phone = File.open("employee_phone_api.txt", "w+")
>> phone.puts fetch_urls(jdoc, 'email_contact_method_reference', 'Mobile').join("\n")
>> phone.close
>> File.read(phone)
#=> "https://pagerduty.com/users/000000/contact/000000\n"