Now I'm fetching data from another url...
Here is my code:
require 'rubygems'
require 'nokogiri'
html = page.body
doc = Nokogiri::HTML(html)
doc.encoding = 'utf-8'
rows = doc.search('//table[#id = "MainContent_GridView1"]//tr')
#details = rows.collect do |row|
detail = {}
[
[:car, 'td[1]/text()'],
[:article, 'td[2]/text()'],
[:group, 'td[3]/text()'],
[:price, 'td[4]/text()'],
].each do |name, xpath|
detail[name] = row.at_xpath(xpath).to_s.strip
end
detail
end
#details
I tried to do it via array, not a hash. But I get a lot of errors...
Are there any ideas?
I need it for another method...
also i set data (this result hash) to another car here:
oem_art = []
#constr_num.each do |o|
as_oem = get_from_as_oem(o.ARL_SEARCH_NUMBER)
if as_oem.present?
oem_art << as_oem
end
end
#oem_art = oem_art.to_a.uniq
Do you just want to change a hash into an array? If so, just use the to_a method on your hash.
hash = {:a => "something", :b => "something else"}
array = hash.to_a
array.inspect #=> [[:a, "something"], [:b, "something else"]]
It looks like you're looking for something like hash['key'] to hash.key in Ruby
The Hash Class doesn't support .key notation by default, OpenStruct creates an Object from the Hash so you can use dot notation to access the properties. Overall it's basically just syntactic sugar with overhead.
Suggested code (from linked answer)
>> require 'ostruct'
=> []
>> foo = {'bar'=>'baz'}
=> {"bar"=>"baz"}
>> foo_obj = OpenStruct.new foo
=> #<OpenStruct bar="baz">
>> foo_obj.bar
=> "baz"
So in your example, you could do:
# Initialised somewhere
require 'ostruct'
DETAIL_INDICES = {
:car => 1,
:article => 2,
:group => 3,
:price => 4,
}
# ** SNIP **
#details = rows.map do |row|
DETAIL_INDICES.inject({}) do |h,(k,v)|
h.merge(k => row.at_xpath("td[#{v}]/text()").to_s.strip)
end
end.collect { |hash| OpenStruct.new hash }
#details.each do |item|
puts item.car
end
Of course if performance is a concern you can merge your map&collect (They are the same), but this is just a minor separation for basic semantic differences, although I usually only use map for consistency, so feel free to choose yourself :)
EDIT -- Additional code from your edit simplified
#oem_art = #constr_num.select do |item|
as_oem = get_from_as_oem(item.ARL_SEARCH_NUMBER)
as_oem.present?
end
puts #oem_art.uniq
Related
The following returns the default "client?":
class ClientMap
def initialize
##clients = {"DP000459": "BP"}
##clients.default = "client?"
end
def get(id)
return ##clients[:id]
end
end
clientMap = ClientMap.new
cKey = "DP000459"
puts clientMap.get(cKey)
Could anybody explain why I cannot retrieve anything but the 'default'?
You've got two problems. First, you are using the symbol syntax in your hash, which works only if your keys are symbols. If you want keys to be strings, you need to use hash-rocket syntax: ##clients = {'DP000459' => 'BP'}.
Second, your method returns clients[:id] regardless of what parameter is provided. The key is the symbol :id rather than the local variable id. You need to change this to ##clients[id].
Here's a cleaned-up version of what you want:
class ClientMap
def initialize
##clients = {'DP000459' => 'BP'}
##clients.default = 'client?'
end
def get(id)
##clients[id]
end
end
I've also taken the liberty of making the spacing more Ruby-idiomatic.
Finally, for variable names in Ruby, use snake_case:
>> client_map = ClientMap.new
>> c_key = 'DP000459'
>> client_map.get(c_key)
#> "BP"
Look at these code:
h = { foo: 'bar' } # => {:foo=>"bar"}
h.default = 'some default value' # => "some default value"
h[:foo] # => "bar"
h[:non_existing_key] # => "some default value"
You can read here about Hash#default method
Returns the default value, the value that would be returned by hsh if
key did not exist in hsh
I'm trying to use Nokogiri in a rails 4.2.0 environment to parse a data sheet of classes. What I intend is to have each course parsed, with the #catalog_nbr, #subject attributes stored, as well as the first instructor listed. The code I have below simply yields empty arrays. I believe the problem has to do with using the .each method, but I can't figure it out!
require 'nokogiri'
require 'open-uri'
doc = Nokogiri::HTML( open("https://courseroster.reg.cornell.edu/courses/roster/SP15/CS/xml/") )
doc.xpath("//course").each do
num = doc.xpath("./#catalog_nbr").text
subject = doc.xpath("./#subject").text
instructor = doc.xpath("./sections/section/meeting/instructors/instructor")[1].text
Course.create(:subject => subject, :number => num, :instructor => instructor)
end
Try this.
After selecting the doc, we need to traverse each of the rows in the document. Lets call each of that rows as row
Next. Assign default values if they are blank. Read this article to get more information on this.
doc.xpath("//course").each do |row|
num = row.xpath("./#catalog_nbr").text || "N/A"
subject = row.xpath("./#subject").text || "N/A"
instructor = row.xpath("./sections/section/meeting/instructors/instructor")[1].text || "N/A"
Course.create(:subject => subject, :number => num, :instructor => instructor)
end
Here's a working solution. Note that the XML file you have linked to always has both catalog numbers and subjects for each course, so there's no need for any || "N/A" there (but perhaps it's nice to be safe):
require 'nokogiri'
require 'open-uri'
doc = Nokogiri.XML( open("https://courseroster.reg.cornell.edu/courses/roster/SP15/CS/xml/") )
doc.xpath("/courses/course").each do |course|
num = course["catalog_nbr"] || "N/A" # in case it doesn't exist
subj = course["subject"] || "N/A" # in case it doesn't exist
inst = (course.at("sections/section/meeting/instructors/instructor/text()") || "N/A").to_s
data = { subject:subj, number:num, instructor:inst }
p data
end
#=> {:subject=>"CS", :number=>"1110", :instructor=>"Van Loan,C (cfv3)"}
#=> {:subject=>"CS", :number=>"1112", :instructor=>"Fan,K (kdf4)"}
#=> {:subject=>"CS", :number=>"1130", :instructor=>"Frey,C (ccf27)"}
#=> {:subject=>"CS", :number=>"1130", :instructor=>"Frey,C (ccf27)"}
#=> {:subject=>"CS", :number=>"1132", :instructor=>"Fan,K (kdf4)"}
#=> etc.
In our Rails 3.2.13 app (Ruby 2.0.0 + Postgres on Heroku), we are often retreiving a large amount of Order data from an API, and then we need to update or create each order in our database, as well as the associations. A single order creates/updates itself plus approx. 10-15 associcated objects, and we are importing up to 500 orders at a time.
The below code works, but the problem is it's not at all efficient in terms of speed. Creating/updating 500 records takes approx. 1 minute and generates 6500+ db queries!
def add_details(shop, shopify_orders)
shopify_orders.each do |shopify_order|
order = Order.where(:order_id => shopify_order.id.to_s, :shop_id => shop.id).first_or_create
order.update_details(order,shopify_order,shop) #This calls update_attributes for the Order
ShippingLine.add_details(order, shopify_order.shipping_lines)
LineItem.add_details(order, shopify_order.line_items)
Taxline.add_details(order, shopify_order.tax_lines)
Fulfillment.add_details(order, shopify_order.fulfillments)
Note.add_details(order, shopify_order.note_attributes)
Discount.add_details(order, shopify_order.discount_codes)
billing_address = shopify_order.billing_address rescue nil
if !billing_address.blank?
BillingAddress.add_details(order, billing_address)
end
shipping_address = shopify_order.shipping_address rescue nil
if !shipping_address.blank?
ShippingAddress.add_details(order, shipping_address)
end
payment_details = shopify_order.payment_details rescue nil
if !payment_details.blank?
PaymentDetail.add_details(order, payment_details)
end
end
end
def update_details(order,shopify_order,shop)
order.update_attributes(
:order_name => shopify_order.name,
:order_created_at => shopify_order.created_at,
:order_updated_at => shopify_order.updated_at,
:status => Order.get_status(shopify_order),
:payment_status => shopify_order.financial_status,
:fulfillment_status => Order.get_fulfillment_status(shopify_order),
:payment_method => shopify_order.processing_method,
:gateway => shopify_order.gateway,
:currency => shopify_order.currency,
:subtotal_price => shopify_order.subtotal_price,
:subtotal_tax => shopify_order.total_tax,
:total_discounts => shopify_order.total_discounts,
:total_line_items_price => shopify_order.total_line_items_price,
:total_price => shopify_order.total_price,
:total_tax => shopify_order.total_tax,
:total_weight => shopify_order.total_weight,
:taxes_included => shopify_order.taxes_included,
:shop_id => shop.id,
:email => shopify_order.email,
:order_note => shopify_order.note
)
end
So as you can see, we are looping through each order, finding out if it exists or not (then either loading the existing Order or creating the new Order), and then calling update_attributes to pass in the details for the Order. After that we create or update each of the associations. Each associated model looks very similar to this:
class << self
def add_details(order, tax_lines)
tax_lines.each do |shopify_tax_line|
taxline = Taxline.find_or_create_by_order_id(:order_id => order.id)
taxline.update_details(shopify_tax_line)
end
end
end
def update_details(tax_line)
self.update_attributes(:price => tax_line.price, :rate => tax_line.rate, :title => tax_line.title)
end
I've looked into the activerecord-import gem but unfortunately it seems to be more geared towards creation of records in bulk and not update as we also require.
What is the best way that this can be improved for performance?
Many many thanks in advance.
UPDATE:
I came up with this slight improvement, which essentialy removes the call to update the newly created Orders (one query less per order).
def add_details(shop, shopify_orders)
shopify_orders.each do |shopify_order|
values = {:order_id => shopify_order.id.to_s, :shop_id => shop.id,
:order_name => shopify_order.name,
:order_created_at => shopify_order.created_at,
:order_updated_at => shopify_order.updated_at,
:status => Order.get_status(shopify_order),
:payment_status => shopify_order.financial_status,
:fulfillment_status => Order.get_fulfillment_status(shopify_order),
:payment_method => shopify_order.processing_method,
:gateway => shopify_order.gateway,
:currency => shopify_order.currency,
:subtotal_price => shopify_order.subtotal_price,
:subtotal_tax => shopify_order.total_tax,
:total_discounts => shopify_order.total_discounts,
:total_line_items_price => shopify_order.total_line_items_price,
:total_price => shopify_order.total_price,
:total_tax => shopify_order.total_tax,
:total_weight => shopify_order.total_weight,
:taxes_included => shopify_order.taxes_included,
:email => shopify_order.email,
:order_note => shopify_order.note}
get_order = Order.where(:order_id => shopify_order.id.to_s, :shop_id => shop.id)
if get_order.blank?
order = Order.create(values)
else
order = get_order.first
order.update_attributes(values)
end
ShippingLine.add_details(order, shopify_order.shipping_lines)
LineItem.add_details(order, shopify_order.line_items)
Taxline.add_details(order, shopify_order.tax_lines)
Fulfillment.add_details(order, shopify_order.fulfillments)
Note.add_details(order, shopify_order.note_attributes)
Discount.add_details(order, shopify_order.discount_codes)
billing_address = shopify_order.billing_address rescue nil
if !billing_address.blank?
BillingAddress.add_details(order, billing_address)
end
shipping_address = shopify_order.shipping_address rescue nil
if !shipping_address.blank?
ShippingAddress.add_details(order, shipping_address)
end
payment_details = shopify_order.payment_details rescue nil
if !payment_details.blank?
PaymentDetail.add_details(order, payment_details)
end
end
end
and for the associated objects:
class << self
def add_details(order, tax_lines)
tax_lines.each do |shopify_tax_line|
values = {:order_id => order.id,
:price => tax_line.price,
:rate => tax_line.rate,
:title => tax_line.title}
get_taxline = Taxline.where(:order_id => order.id)
if get_taxline.blank?
taxline = Taxline.create(values)
else
taxline = get_taxline.first
taxline.update_attributes(values)
end
end
end
end
Any better suggestions?
Try wrapping your entire code into a single database transaction. Since you're on Heroku it'll be a Postgres bottom-end. With that many update statements, you can probably benefit greatly by transacting them all at once, so your code executes quicker and basically just leaves a "queue" of 6500 statements to run on Postgres side as the server is able to dequeue them. Depending on the bottom end, you might have to transact into smaller chunks - but even transacting 100 at a time (and then close and re-open the transaction) would greatly improve throughput into Pg.
http://api.rubyonrails.org/classes/ActiveRecord/Transactions/ClassMethods.html
http://www.postgresql.org/docs/9.2/static/sql-set-transaction.html
So before line 2 you'd add something like:
def add_details(shop, shopify_orders)
Order.transaction do
shopify_orders.each do |shopify_order|
And then at the very end of your method add another end:
if !payment_details.blank?
PaymentDetail.add_details(order, payment_details)
end
end //shopify_orders.each..
end //Order.transaction..
end //method
You can monkey-patch ActiveRecord like this:
class ActiveRecord::Base
#http://stackoverflow.com/questions/15317837/bulk-insert-records-into-active-record-table?lq=1
#https://gist.github.com/jackrg/76ade1724bd816292e4e
# "UPDATE THIS SET <list_of_column_assignments> FROM <table_name> THIS JOIN (VALUES (<csv1>, <csv2>,...) VALS ( <column_names> ) ON <list_of_primary_keys_comparison>"
def self.bulk_update(record_list)
pk = self.primary_key
raise "primary_key not found" unless pk.present?
raise "record_list not an Array of Hashes" unless record_list.is_a?(Array) && record_list.all? {|rec| rec.is_a? Hash }
return nil if record_list.empty?
result = nil
#test if every hash has primary keys, so we can JOIN
record_list.each { |r| raise "Primary Keys '#{self.primary_key.to_s}' not found on record: #{r}" unless hasAllPKs?(r) }
#list of primary keys comparison
pk_comparison_array = []
if (pk).is_a?(Array)
pk.each {|thiskey| pk_comparison_array << "THIS.#{thiskey} = VALS.#{thiskey}" }
else
pk_comparison_array << "THIS.#{pk} = VALS.#{pk}"
end
pk_comparison = pk_comparison_array.join(' AND ')
#SQL
(1..record_list.count).step(1000).each do |start|
key_list, value_list = convert_record_list(record_list[start-1..start+999])
#csv values
csv_vals = value_list.map {|v| "(#{v.join(", ")})" }.join(", ")
#column names
column_names = key_list.join(", ")
#list of columns assignments
columns_assign_array = []
key_list.each {|col|
unless inPK?(col)
columns_assign_array << "THIS.#{col} = VALS.#{col}"
end }
columns_assign = columns_assign_array.join(', ')
sql = "UPDATE THIS SET #{columns_assign} FROM #{self.table_name} THIS JOIN ( VALUES #{csv_vals} ) VALS ( #{column_names} ) ON ( #{pk_comparison} )"
result = self.connection.execute(sql)
return result if result<0
end
return result
end
def self.inPK?(str)
pk = self.primary_key
test = str.to_s
if pk.is_a?(Array)
(pk.include?(test))
else
(pk==test)
end
end
#test if given hash has primary keys included as hash keys and those keys are not empty
def self.hasAllPKs?(hash)
h = hash.stringify_keys
pk = self.primary_key
if pk.is_a?(Array)
(pk.all? {|k| h.key?(k) and h[k].present? })
else
h.key?(pk) and h[pk].present?
end
end
def self.convert_record_list(record_list)
# Build the list of keys
key_list = record_list.map(&:keys).flatten.map(&:to_s).uniq.sort
value_list = record_list.map do |rec|
list = []
key_list.each {|key| list << ActiveRecord::Base.connection.quote(rec[key] || rec[key.to_sym]) }
list
end
# If table has standard timestamps and they're not in the record list then add them to the record list
time = ActiveRecord::Base.connection.quote(Time.now)
for field_name in %w(created_at updated_at)
if self.column_names.include?(field_name) && !(key_list.include?(field_name))
key_list << field_name
value_list.each {|rec| rec << time }
end
end
return [key_list, value_list]
end
end
Then, you can generate a array of hashes containing your models attributes (including theirs primary keys) and do something like:
ActiveRecord::Base.transaction do
Model.bulk_update [ {attr1: val1, attr2: val2,...}, {attr1: val1, attr2: val2,...}, ... ]
end
It will be a single SQL command without Rails callbacks and validations.
For PostgreSQL, there are several issues that the above approach does not address:
You must specify an actual table, not just an alias, in the update target table.
You cannot repeat the target table in the FROM phrase. Since you are joining the target table to a VALUES table (hence there is only one table in the FROM phrase, you won't be able to use JOIN, you must instead use "WHERE ".
You don't get the same "free" casts in a VALUES table that you do in a simple "UPDATE" command, so you must cast date/timestamp values as such (#val_cast does this).
class ActiveRecord::Base
def self.update!(record_list)
raise ArgumentError "record_list not an Array of Hashes" unless record_list.is_a?(Array) && record_list.all? {|rec| rec.is_a? Hash }
return record_list if record_list.empty?
(1..record_list.count).step(1000).each do |start|
field_list, value_list = convert_record_list(record_list[start-1..start+999])
key_field = self.primary_key
non_key_fields = field_list - [%Q["#{self.primary_key}"], %Q["created_at"]]
columns_assign = non_key_fields.map {|field| "#{field} = #{val_cast(field)}"}.join(",")
value_table = value_list.map {|row| "(#{row.join(", ")})" }.join(", ")
sql = "UPDATE #{table_name} AS this SET #{columns_assign} FROM (VALUES #{value_table}) vals (#{field_list.join(", ")}) WHERE this.#{key_field} = vals.#{key_field}"
self.connection.update_sql(sql)
end
return record_list
end
def self.val_cast(field)
field = field.gsub('"', '')
if (column = columns.find{|c| c.name == field }).sql_type =~ /time|date/
"cast (vals.#{field} as #{column.sql_type})"
else
"vals.#{field}"
end
end
def self.convert_record_list(record_list)
# Build the list of fields
field_list = record_list.map(&:keys).flatten.map(&:to_s).uniq.sort
value_list = record_list.map do |rec|
list = []
field_list.each {|field| list << ActiveRecord::Base.connection.quote(rec[field] || rec[field.to_sym]) }
list
end
# If table has standard timestamps and they're not in the record list then add them to the record list
time = ActiveRecord::Base.connection.quote(Time.now)
for field_name in %w(created_at updated_at)
if self.column_names.include?(field_name) && !(field_list.include?(field_name))
field_list << field_name
value_list.each {|rec| rec << time }
end
end
field_list.map! {|field| %Q["#{field}"] }
return [field_list, value_list]
end
end
What is the best way to achieve the following, I have following array of actions under ABC
ABC:-
ABC:Actions,
ABC:Actions:ADD-DATA,
ABC:Actions:TRANSFER-DATA,
ABC:Actions:EXPORT,
ABC:Actions:PRINT,
ABC:Detail,
ABC:Detail:OVERVIEW,
ABC:Detail:PRODUCT-DETAIL,
ABC:Detail:EVENT-LOG,
ABC:Detail:ORDERS
I want to format this as:
ABC =>{Actions=> [ADD-DATA,TRANSFER-DATA,EXPORT,PRINT], Detail => [Overview, Product-detail, event-log,orders]}
There's probably a ton of ways to do it but here's one:
a = ["ABC:Actions",
"ABC:Actions:ADD-DATA",
"ABC:Actions:TRANSFER-DATA",
"ABC:Actions:EXPORT",
"ABC:Actions:PRINT",
"ABC:Detail",
"ABC:Detail:OVERVIEW",
"ABC:Detail:PRODUCT-DETAIL",
"ABC:Detail:EVENT-LOG",
"ABC:Detail:ORDERS"]
a.map { |action| action.split(":") }.inject({}) do |m, s|
m[s.at(0)] ||= {}
m[s.at(0)][s.at(1)] ||= [] if s.at(1)
m[s.at(0)][s.at(1)] << s.at(2) if s.at(2)
m
end
The map call returns an array where each of the strings in the original array have been split into an array of elements that were separated by :. For example [["ABC","Actions","ADD-DATA"] ... ]
The inject call then builds up a hash by going through each of these "split" arrays. It creates a mapping for the first element, if one doesn't already exist, to an empty hash, e.g. "ABC" => {}. Then it creates a mapping in that hash for the second element, if one doesn't already exist, to an empty array, e.g. "ABC" => { "Detail" => [] }. Then it adds the third element to that array to give something like "ABC" => { "Detail" => ["OVERVIEW"] }. Then it goes onto the next "split" array and adds that to the hash too in the same way.
I will do this as below :
a = ["ABC:Actions",
"ABC:Actions:ADD-DATA",
"ABC:Actions:TRANSFER-DATA",
"ABC:Actions:EXPORT",
"ABC:Actions:PRINT",
"ABC:Detail",
"ABC:Detail:OVERVIEW",
"ABC:Detail:PRODUCT-DETAIL",
"ABC:Detail:EVENT-LOG",
"ABC:Detail:ORDERS"]
m = a.map{|i| i.split(":")[1..-1]}
# => [["Actions"],
# ["Actions", "ADD-DATA"],
# ["Actions", "TRANSFER-DATA"],
# ["Actions", "EXPORT"],
# ["Actions", "PRINT"],
# ["Detail"],
# ["Detail", "OVERVIEW"],
# ["Detail", "PRODUCT-DETAIL"],
# ["Detail", "EVENT-LOG"],
# ["Detail", "ORDERS"]]
m.each_with_object(Hash.new([])){|(i,j),ob| ob[i] = ob[i] + [j] unless j.nil? }
# => {"Actions"=>["ADD-DATA", "TRANSFER-DATA", "EXPORT", "PRINT"],
# "Detail"=>["OVERVIEW", "PRODUCT-DETAIL", "EVENT-LOG", "ORDERS"]}
It was just interesting to do it with group_by :)
a = ['ABC:Actions',
'ABC:Actions:ADD-DATA',
'ABC:Actions:TRANSFER-DATA',
'ABC:Actions:EXPORT',
'ABC:Actions:PRINT',
'ABC:Detail',
'ABC:Detail:OVERVIEW',
'ABC:Detail:PRODUCT-DETAIL',
'ABC:Detail:EVENT-LOG',
'ABC:Detail:ORDERS']
result = a.map { |action| action.split(":") }.group_by(&:shift)
result.each do |k1,v1|
result[k1] = v1.group_by(&:shift)
result[k1].each { |k2,v2| result[k1][k2] = v2.flatten }
end
p result
{"ABC"=>{"Actions"=>["ADD-DATA", "TRANSFER-DATA", "EXPORT", "PRINT"], "Detail"=>["OVERVIEW", "PRODUCT-DETAIL", "EVENT-LOG", "ORDERS"]}}
I am wondering what is the best way to convert a json formatted key value pair to ruby hash with symbol as key:
example:
{ 'user': { 'name': 'foo', 'age': 40, 'location': { 'city' : 'bar', 'state': 'ca' } } }
==>
{ :user=>{ :name => 'foo', :age =>'40', :location=>{ :city => 'bar', :state=>'ca' } } }
Is there a helper method can do this?
using the json gem when parsing the json string you can pass in the symbolize_names option. See here: http://flori.github.com/json/doc/index.html (look under parse)
eg:
>> s ="{\"akey\":\"one\",\"bkey\":\"two\"}"
>> JSON.parse(s,:symbolize_names => true)
=> {:akey=>"one", :bkey=>"two"}
Leventix, thank you for your answer.
The Marshal.load(Marshal.dump(h)) method probably has the most integrity of the various methods because it preserves the original key types recursively.
This is important in case you have a nested hash with a mix of string and symbol keys and you want to preserve that mix upon decode (for instance, this could happen if your hash contains your own custom objects in addition to highly complex/nested third-party objects whose keys you cannot manipulate/convert for whatever reason, like a project time constraint).
E.g.:
h = {
:youtube => {
:search => 'daffy', # nested symbol key
'history' => ['goofy', 'mickey'] # nested string key
}
}
Method 1: JSON.parse - symbolizes all keys recursively => Does not preserve original mix
JSON.parse( h.to_json, {:symbolize_names => true} )
=> { :youtube => { :search=> "daffy", :history => ["goofy", "mickey"] } }
Method 2: ActiveSupport::JSON.decode - symbolizes top-level keys only => Does not preserve original mix
ActiveSupport::JSON.decode( ActiveSupport::JSON.encode(h) ).symbolize_keys
=> { :youtube => { "search" => "daffy", "history" => ["goofy", "mickey"] } }
Method 3: Marshal.load - preserves original string/symbol mix in the nested keys. PERFECT!
Marshal.load( Marshal.dump(h) )
=> { :youtube => { :search => "daffy", "history" => ["goofy", "mickey"] } }
Unless there is a drawback that I'm unaware of, I'd think Method 3 is the way to go.
Cheers
There isn't anything built in to do the trick, but it's not too hard to write the code to do it using the JSON gem. There is a symbolize_keys method built into Rails if you're using that, but that doesn't symbolize keys recursively like you need.
require 'json'
def json_to_sym_hash(json)
json.gsub!('\'', '"')
parsed = JSON.parse(json)
symbolize_keys(parsed)
end
def symbolize_keys(hash)
hash.inject({}){|new_hash, key_value|
key, value = key_value
value = symbolize_keys(value) if value.is_a?(Hash)
new_hash[key.to_sym] = value
new_hash
}
end
As Leventix said, the JSON gem only handles double quoted strings (which is technically correct - JSON should be formatted with double quotes). This bit of code will clean that up before trying to parse it.
Recursive method:
require 'json'
def JSON.parse(source, opts = {})
r = JSON.parser.new(source, opts).parse
r = keys_to_symbol(r) if opts[:symbolize_names]
return r
end
def keys_to_symbol(h)
new_hash = {}
h.each do |k,v|
if v.class == String || v.class == Fixnum || v.class == Float
new_hash[k.to_sym] = v
elsif v.class == Hash
new_hash[k.to_sym] = keys_to_symbol(v)
elsif v.class == Array
new_hash[k.to_sym] = keys_to_symbol_array(v)
else
raise ArgumentError, "Type not supported: #{v.class}"
end
end
return new_hash
end
def keys_to_symbol_array(array)
new_array = []
array.each do |i|
if i.class == Hash
new_array << keys_to_symbol(i)
elsif i.class == Array
new_array << keys_to_symbol_array(i)
else
new_array << i
end
end
return new_array
end
Of course, there is a json gem, but that handles only double quotes.
Another way to handle this is to use YAML serialization/deserialization, which also preserves the format of the key:
YAML.load({test: {'test' => { ':test' => 5}}}.to_yaml)
=> {:test=>{"test"=>{":test"=>5}}}
Benefit of this approach it seems like a format that is better suited for REST services...
The most convenient way is by using the nice_hash gem: https://github.com/MarioRuiz/nice_hash
require 'nice_hash'
my_str = "{ 'user': { 'name': 'foo', 'age': 40, 'location': { 'city' : 'bar', 'state': 'ca' } } }"
# on my_hash will have the json as a hash
my_hash = my_str.json
# or you can filter and get what you want
vals = my_str.json(:age, :city)
# even you can access the keys like this:
puts my_hash._user._location._city
puts my_hash.user.location.city
puts my_hash[:user][:location][:city]
If you think you might need both string and symbol keys:
JSON.parse(json_string).with_indifferent_access