I iterate through all cars and its supported attributes (many attributes per car) to create a structure like this, how do I do this in a dynamic fashion.
cars = {
"honda" => {'color' => 'blue', 'type' => 'sedan'}.
"nissan" => {'color' => 'yellow', 'type' => 'sports'}.
...
}
cars.each do |car|
car_attrs = ...
car_attrs.each do |attr|
??? How to construct the above structure
end
end
Your question is not very clear... But i guess this is what you want:
cars = {}
options = {}
options['color'] = 'blue'
...
cars['honda'] = options
Is that what you were looking for?
It sounds like you may be asking for a way to create a 2-dimensional hash without having to explicitly create each child hash. One way to accomplish that is by specifying the default object created for a hash key.
# When we create the cars hash, we tell it to create a new Hash
# for undefined keys
cars = Hash.new { |hash, key| hash[key] = Hash.new }
# We can then assign values two-levels deep as follows
cars["honda"]["color"] = "blue"
cars["honda"]["type"] = "sedan"
cars["nissan"]["color"] = "yellow"
cars["nissan"]["type"] = "sports"
# But be careful not to check for nil using the [] operator
# because a default hash is now created when using it
puts "Found a Toyota" if cars["toyota"]
# The correct way to check would be
puts "Really found a Toyota" if cars.has_key? "toyota"
Many client libraries assume that the [] operator returns a nil default, so make sure other code doesn't depend on that behavior before using this solution. Good luck!
Assuming you are using something similar to ActiveRecord (but easy to modify if you are not):
cars_info = Hash[cars.map { |car| [car.name, car.attributes] }
Related
I am currently trying to create a hash out of an xml documen, with the help of the ox gem
Input xml:
<?xml version="1.0"?>
<expense>
<payee>starbucks</payee>
<amount>5.75</amount>
<date>2017-06-10</date>
</expense>
with the following ruby/ox code:
doc = Ox.parse(xml)
plist = doc.root.nodes
I get the following output:
=> [#<Ox::Element:0x00007f80d985a668 #value="payee", #attributes={}, #nodes=["starbucks"]>, #<Ox::Element:0x00007f80d9839198 #value="amount", #attributes={}, #nodes=["5.75"]>, #<Ox::Element:0x00007f80d9028788 #value="date", #attributes={}, #nodes=["2017-06-10"]>]
The output I want is a hash in the format:
{'payee' => 'Starbucks',
'amount' => 5.75,
'date' => '2017-06-10'}
to save in my sqllite database. How can I transform the objects array into a hash like above.
Any help is highly appreciated.
The docs suggest you can use the following:
require 'ox'
xml = %{
<top name="sample">
<middle name="second">
<bottom name="third">Rock bottom</bottom>
</middle>
</top>
}
puts Ox.load(xml, mode: :hash)
puts Ox.load(xml, mode: :hash_no_attrs)
#{:top=>[{:name=>"sample"}, {:middle=>[{:name=>"second"}, {:bottom=>[{:name=>"third"}, "Rock bottom"]}]}]}
#{:top=>{:middle=>{:bottom=>"Rock bottom"}}}
I'm not sure that's exactly what you're looking for though.
Otherwise, it really depends on the methods available on the Ox::Element instances in the array.
From the docs, it looks like there are two handy methods here: you can use [] and text.
Therefore, I'd use reduce to coerce the array into the hash format you're looking for, using something like the following:
ox_nodes = [#<Ox::Element:0x00007f80d985a668 #value="payee", #attributes={}, #nodes=["starbucks"]>, #<Ox::Element:0x00007f80d9839198 #value="amount", #attributes={}, #nodes=["5.75"]>, #<Ox::Element:0x00007f80d9028788 #value="date", #attributes={}, #nodes=["2017-06-10"]>]
ox_nodes.reduce({}) do |hash, node|
hash[node['#value']] = node.text
hash
end
I'm not sure whether node['#value'] will work, so you might need to experiment with that - otherwise perhaps node.instance_variable_get('#value') would do it.
node.text does the following, which sounds about right:
Returns the first String in the elements nodes array or nil if there is no String node.
N.B. I prefer to tidy the reduce block a little using tap, something like the following:
ox_nodes.reduce({}) do |hash, node|
hash.tap { |h| h[node['#value']] = node.text }
end
Hope that helps - let me know how you get on!
I found the answer to the question in my last comment by myself:
def create_xml(expense)
Ox.default_options=({:with_xml => false})
doc = Ox::Document.new(:version => '1.0')
expense.each do |key, value|
e = Ox::Element.new(key)
e << value
doc << e
end
Ox.dump(doc)
end
The next question would be how can i transform the value of the amount key from a string to an integer befopre saving it to the database
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?
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"
I've struggled with this problem for a while, and I'm finally going to ask here for help.
Take a very straightforward hash that represents some event:
{
:eventkey=>"someeventkey",
:web_id=>"77d5f434-5a40-4582-88e8-9667b7774c7d",
:apikey=>"eaf3b6e1-b020-41b6-b67f-98f1cc0a9590",
:details=> {
:phone=>"1-936-774-6886",
:email=>"dasia_schuster#wisokytrantow.com",
:pageUrl=>"http://ortiz.info/joe"
}
}
My goal is to create a 'master record' for the entire hash, with the fields in the record being all the keys that do not contain values that are also hashes. When I run into a value that is a hash (in this case 'details'), I need to create a separate record for each k/v pair in that hash bearing the same record id as the parent master record.
I'm not getting the recursion right somehow. Ideally I would get back a single primary record:
{
:recordid=>"some-generated-record-id",
:web_id=>"77d5f434-5a40-4582-88e8-9667b7774c7d",
:apikey=>"eaf3b6e1-b020-41b6-b67f-98f1cc0a9590",
:details=>nil
}
And a distinct entry for each key in the nested hash:
{
:recordid=>"some-generated-detail-record-id",
:parentid=>"the-parent-id-from-the-master-record",
:phone=>"1-936-774-6886"
}
{
:recordid=>"another-generated-detail-record-id",
:parentid=>"the-same-parent-id-from-the-master-record",
:email=>"dasia_schuster#wisokytrantow.com"
}
And so on. I'm trying to get this set of records back as an array of hashes.
I've gotten as far as being able to generate the master record, as well as a detail record, but the detail record contains all the keys in the detail.
def eventToBreakout(eventhash,sequenceid = -1, parentrecordid = nil, records = [])
recordid = SecureRandom.uuid
sequenceid += 1
recordstruc = {:record_id => recordid, :parent_record_id => parentrecordid, :record_processed_ts => Time.now, :sequence_id => sequenceid}
eventhash.each_pair do |k,v|
if recurse?(v)
eventToBreakout(v,sequenceid,recordid,records)
else
if !recordstruc.keys.include?(k)
recordstruc[k]=v
end
end
end
records << recordstruc
records
end
I've included my code and here is the output I'm currently getting from it.
[{:record_id=>"ed98be89-4c1f-496e-beb4-ede5f38dd549",
:parent_record_id=>"fa77299b-95b0-429d-ad8a-f5d365f2f357",
:record_processed_ts=>2016-04-25 16:46:10 -0500,
:sequence_id=>1,
:phone=>"1-756-608-8114",
:email=>"hipolito_wilderman#morar.co",
:pageUrl=>"http://haag.net/alexie.marvin"},
{:record_id=>"fa77299b-95b0-429d-ad8a-f5d365f2f357",
:parent_record_id=>nil,
:record_processed_ts=>2016-04-25 16:46:10 -0500,
:sequence_id=>0,
:eventts=>2016-04-25 22:10:32 -0500,
:web_id=>"a61c57ae-3a01-4994-8803-8d8292df3338",
:apikey=>"9adbc7a4-03ff-4fcc-ac81-ae8d0ee01ef0"}]
Maybe you want something along these lines?
input = { id: 'parent', value: 'parent value', child: { child_value: 1}}
record = {}
input.each do |k,v|
if v.is_a? Hash
v[:parent_id] = input[:id]
(record[:children] ||= []) << v
else
record[k] = v
end
end
puts record
# {:id=>"parent", :value=>"parent value", :children=>[{:child_value=>1, :parent_id=>"parent"}]}
By the way this is a good example to get started with "spec" or "test" frameworks like minitest or rspec (both can be used for both). You have defined input and expected output already and "just" need to code until all test/spec-runs are green.
I'd like to structure data I get pack from an Instagram API call:
{"attribution"=>nil,
"tags"=>["loudmouth"],
"location"=>{"latitude"=>40.7181015, "name"=>"Fontanas Bar", "longitude"=>-73.9922791, "id"=>31443955},
"comments"=>{"count"=>0, "data"=>[]},
"filter"=>"Normal",
"created_time"=>"1444181565",
"link"=>"https://instagram.com/p/8hJ-UwIDyC/",
"likes"=>{"count"=>0, "data"=>[]},
"images"=>
{"low_resolution"=>{"url"=>"https://scontent.cdninstagram.com/hphotos-xaf1/t51.2885-15/s320x320/e35/12145134_169501263391761_636095824_n.jpg", "width"=>320, "height"=>320},
"thumbnail"=>
{"url"=>"https://scontent.cdninstagram.com/hphotos-xfa1/t51.2885-15/s150x150/e35/c135.0.810.810/12093266_813307028768465_178038954_n.jpg", "width"=>150, "height"=>150},
"standard_resolution"=>
{"url"=>"https://scontent.cdninstagram.com/hphotos-xaf1/t51.2885-15/s640x640/sh0.08/e35/12145134_169501263391761_636095824_n.jpg", "width"=>640, "height"=>640}},
"users_in_photo"=>
[{"position"=>{"y"=>0.636888889, "x"=>0.398666667},
"user"=>
{"username"=>"ambersmelson",
"profile_picture"=>"http://photos-h.ak.instagram.com/hphotos-ak-xfa1/t51.2885-19/11909108_1492226137759631_1159527917_a.jpg",
"id"=>"194780705",
"full_name"=>""}}],
"caption"=>
{"created_time"=>"1444181565",
"text"=>"the INCOMPARABLE Amber Nelson closing us out! #loudmouth",
"from"=>
{"username"=>"alex3nglish",
"profile_picture"=>"http://photos-f.ak.instagram.com/hphotos-ak-xaf1/t51.2885-19/s150x150/11906214_483262888501413_294704768_a.jpg",
"id"=>"30822062",
"full_name"=>"Alex English"}}
I'd like to structure it in this way:
hash ={}
hash {"item1"=>
:location => {"latitude"=>40.7181015, "name"=>"Fontanas Bar", "longitude"=>-73.9922791, "id"=>31443955},
:created_time => "1444181565",
:images =>https://scontent.cdninstagram.com/hphotos-xaf1/t51.2885-15/s320x320/e35/12145134_169501263391761_636095824_n.jpg"
:user =>"Alex English"}
I'm iterating over 20 objects, each with their location, images, etc... how can I get a hash structure like the one above ?
This is what I've tried:
array_images = Array.new
# iterate through response object to extract what is needed
response.each do |item|
array_images << { :image => item.images.low_resolution.url,
:location => item.location,:created_time => Time.at(item.created_time.to_i), :user => item.user.full_name}
end
Which works fine. So what is the better way, the fastest one?
The hash that you gave is one item in the array stored at the key "data" in a larger hash right? At least that's how it is for the tags/ endpoint so I'll assume it's the same here. (I'm referring to that array of hashes as data)
hash = {}
data.each_with_index do |h, idx|
hash["item#{idx + 1}"] = {
location: h["location"], #This grabs the entire hash at "location" because you are wanting all of that data
created_time: h["created_time"],
image: h["images"]["low_resolution"]["url"], # You can replace this with whichever resolution.
caption: h["caption"]["from"]["full_name"]
}
end
I feel like you want a more simple solution, but I'm not sure how that's going to happen as you want things nested at different levels and you are pulling things from diverse levels of nesting.
I want to try Mongo with Ruby. I connected, selected collection and I can query data from MongoDB.
irb(main):049:0> coll.find_one({:x=>4})
=> #<BSON::OrderedHash:0x3fdb33fdd59c {"_id"=>BSON::ObjectId('4f8ae4d7c0111ba6383cbe1b'), "x"=>4.0, "j"=>1.0}>
irb(main):048:0> coll.find_one({:x=>4}).to_a
=> [["_id", BSON::ObjectId('4f8ae4d7c0111ba6383cbe1b')], ["x", 4.0], ["j", 1.0]]
But how to access propeties, when I retrieve BSON hash? I need something like this:
data.x
=> 4
to_hash method gives me the same BSON::OrderedHash... :(
When you say coll.find_one({:x=>4}), you get a BSON::OrderedHash back that you access like a normal Hash:
h = coll.find_one(:x => 4)
puts h['x']
# 4 comes out unless you didn't find anything.
If you use a full find instead of find_one, you get a MongoDB::Cursor which is an Enumerable so you can iterate it like any other collection; the cursor will return BSON::OrderedHash instances as you iterate so you can do things like this:
cursor = coll.find(:thing => /stuff/)
cursor.each { |h| puts h['thing'] }
things = cursor.map { |h| h['thing'] }
If you wanted objects instead of Hashes then you'd have to wrap the MongoDB::Cursor and BSON::OrderedHash instances with object yourself (possibly via Struct).
Mongodb find_one method returns hash object, find method returns cursor object.
Cursor object can be iterated and then is possible to extract the answer in a normal hash.
require 'rubygems'
require 'mongo'
include Mongo
client = MongoClient.new('localhost', 27017)
db = client.db("mydb")
coll = db.collection("testCollection")
coll.insert({"name"=>"John","lastname"=>"Smith","phone"=>"12345678"})
coll.insert({"name"=>"Jane","lastname"=>"Fonda","phone"=>"87654321"})
cursor = coll.find({"phone"=>"87654321"})
answer = {}
cursor.map { |h| answer = h }
puts answer["name"]