Why I get undefined method `each'? - ruby

In application.rb I tried to read a YAML file:
config.before_configuration do
env_file = File.join(Rails.root, 'config', 'local_env.yml')
YAML.load(File.open(env_file)).each do |key, value|
ENV[key.to_s] = value
end if File.exists?(env_file)
end
but, I get this error:
/var/www/config/application.rb:26:in `block in <class:Application>': undefined method `each' for #<String:0x00000007afb7f0> (NoMethodError)
from /usr/local/rvm/gems/ruby-2.2.1/gems/activesupport-4.1.6/lib/active_support/lazy_load_hooks.rb:36:in `call'
from /usr/local/rvm/gems/ruby-2.2.1/gems/activesupport-4.1.6/lib/active_support/lazy_load_hooks.rb:36:in `execute_hook'
from /usr/local/rvm/gems/ruby-2.2.1/gems/activesupport-4.1.6/lib/active_support/lazy_load_hooks.rb:28:in `block in on_load'
from /usr/local/rvm/gems/ruby-2.2.1/gems/activesupport-4.1.6/lib/active_support/lazy_load_hooks.rb:27:in `each'
from /usr/local/rvm/gems/ruby-2.2.1/gems/activesupport-4.1.6/lib/active_support/lazy_load_hooks.rb:27:in `on_load'
from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.1.6/lib/rails/railtie/configuration.rb:53:in `before_configuration'
from /var/www/config/application.rb:24:in `<class:Application>'
Any idea?
EDIT
My yaml file:
LOAD_JS_FROM_AMAZON:no
RACK_ENV:production
S3_BUCKET_NAME:bucket_name
S3_CMS_BUCKET_NAME:cms_bucket_name

YAML.load(File.open(env_file))
Your YAML is returning a String not a Hash
You need spaces between colon and value:
LOAD_JS_FROM_AMAZON: no
RACK_ENV: production
S3_BUCKET_NAME: bucket_name
S3_CMS_BUCKET_NAME: cms_bucket_name

Related

TypeError: wrong argument type class (expected module) in rspec

i'm developing a simple net application (packed as a gem) to learn Ruby and TDD.
I have this class (receiver.rb):
require 'eventmachine'
class Receiver < EM::Connection
def initialize(port)
EM.run do
EM.open_datagram_socket('0.0.0.0', port, self)
end
end
end
And this test (receiver_spec.rb):
require "spec_helper"
require "net/receiver"
describe "Receiver" do
it "can istantiate" do
#rec = Receiver.new(500)
end
end
Anyway, when i run rspec it prints out this:
1) Receiver can istantiate
Failure/Error: #rec = Receiver.new(500)
TypeError:
wrong argument type Receiver (expected Module)
# /var/lib/gems/1.9.1/gems/eventmachine- 1.0.7/lib/eventmachine.rb:1535:in `include'
# /var/lib/gems/1.9.1/gems/eventmachine-1.0.7/lib/eventmachine.rb:1535:in `block in klass_from_handler'
# /var/lib/gems/1.9.1/gems/eventmachine-1.0.7/lib/eventmachine.rb:1535:in `initialize'
# /var/lib/gems/1.9.1/gems/eventmachine-1.0.7/lib/eventmachine.rb:1535:in `new'
# /var/lib/gems/1.9.1/gems/eventmachine-1.0.7/lib/eventmachine.rb:1535:in `klass_from_handler'
# /var/lib/gems/1.9.1/gems/eventmachine- 1.0.7/lib/eventmachine.rb:867:in `open_datagram_socket'
# ./lib/rppc/net/receiver.rb:9:in `block in initialize'
# /var/lib/gems/1.9.1/gems/eventmachine-1.0.7/lib/eventmachine.rb:187:in `call'
# /var/lib/gems/1.9.1/gems/eventmachine-1.0.7/lib/eventmachine.rb:187:in `run_machine'
# /var/lib/gems/1.9.1/gems/eventmachine-1.0.7/lib/eventmachine.rb:187:in `run'
# ./lib/rppc/net/receiver.rb:8:in `initialize'
# ./spec/net/receiver_spec.rb:6:in `new'
# ./spec/net/receiver_spec.rb:6:in `block (2 levels) in <top (required)>'
I'm quite new to the ruby environment, so if i missed something let me know.
I'm not sure what documentation you're working from, but it appears the open_datagram_socket requires a Module and cannot accept a Class as the third (handler) argument.
Per the comment in http://www.rubydoc.info/github/eventmachine/eventmachine/EventMachine.open_datagram_socket, it appears this restriction may have been loosened in a later version of EventMachine

Ruby: Array of Arrays to Array of Hashes

I have an Array of Arrays (imported from CSV file):
[[title1],[title2],[title3],[title4],[title5]],
[[song1],[author1],[bpm1],[key1],[energy1]],
...
[[song100],[author100],[bpm100],[key100],[energy100]].
and would like to convert it to an Array of Hashes like:
[{"title1"=>"song1","title2"=>"author1","title3"=>"bpm1","title4"=>"key1","title5"=>"energy1"}],
...
[{"title1"=>"song100","title2"=>"author100","title3"=>"bpm100","title4"=>"key100","title5"=>"energy100"}].
I used the code below but it doesn't work:
require 'csv'
csv=CSV.read('library.csv')
array_hash=[]
hash={}
for i in 1..(csv.size)
hash1={}
for n in 0..4
a=csv[0][n]
b=csv[i][n]
hash1[a]=b
hash.merge!(hash1)
end
array_hash.push(hash)
end
But I get:
> NoMethodError: undefined method `[]' for nil:NilClass from
> (irb):149:in `block (2 levels) in irb_binding' from (irb):146:in
> `each' from (irb):146:in `block in irb_binding' from (irb):143:in
> `each' from (irb):143 from
> /Users/user/.rvm/rubies/ruby-2.0.0-p481/bin/irb:12:in `<main>'
What is wrong with this?
How to do the same using .each ?
The ruby CSV library has a to_hash function on CSV::Row, so you can do as below instead:
require 'csv'
rows = CSV.read('library.csv', headers: true).map(&:to_hash) #rows would return a list of hashes

Undefined method each in Ruby Regexp task

I have series of zip files under #workingdir, and am trying to unzip the files that match #Regexp, and print the lines from them.
require 'zip/zip'
#workingdir = '/my/dir/structure/*.zip'
#Regexp = '/yup:maybe.*nope/i'
Dir.glob(#workingdir) do |zips|
Zip::ZipFile.open(zips) do |file|
file.each do |search|
tempFile = file.read(search)
tempFile.each do |line|
if (line =~ #Regexp ) then
p line
end
end
end
end
end
Below is the error message from IRB:
NoMethodError: undefined method `each' for #<String:0x0000000168bf40>
from (irb):70:in `block (3 levels) in irb_binding'
from /var/lib/gems/1.9.1/gems/rubyzip2-2.0.2/lib/zip/zip.rb:1122:in `each'
from /var/lib/gems/1.9.1/gems/rubyzip2-2.0.2/lib/zip/zip.rb:1122:in `each'
from /var/lib/gems/1.9.1/gems/rubyzip2-2.0.2/lib/zip/zip.rb:1265:in `each'
from (irb):68:in `block (2 levels) in irb_binding'
from /var/lib/gems/1.9.1/gems/rubyzip2-2.0.2/lib/zip/zip.rb:1381:in `open'
from (irb):67:in `block in irb_binding'
from (irb):66:in `glob'
from (irb):66
from /usr/bin/irb:12:in `<main>'
I tried tempFile.grep, and received the same error, except that grep was an undefined method. I believe I need to define a class.
Turns out my code had two problems. 1) My regular expression was being processed as a string (I should not have used the quotes). 2) Seeing as it runs fine otherwise on Ruby 1.8.7, I suspect the is a difference in how 1.8.7 and 1.9.1 process the 'each' method. If anyone has additional insights, I'm more than happy to hear them. The code below works fine on 1.8.7:
require 'zip/zip'
#workingdir = '/my/dir/structure/*.zip'
#Regexp = /regexp/i
Dir.glob(#workingdir) do |zips|
Zip::ZipFile.open(zips) do |file|
file.each do |search|
tempFile = file.read(search)
tempFile.each do |line|
if (line =~ #Regexp) then
puts zips + ': ' + line.chomp
end
end
end
end
end
Thanks again everyone!

Ruby Undefined method downcase

I'm getting an exception in the following piece of code. Can someone please tell me what I'm doing wrong, and how I can prevent it?
def self.find_by_data(data = {})
where(name_canonical: data['name'].downcase.gsub(/\s+/, ''),
fuel: data['fuel'],
trim_canonical: data['trim'].downcase.gsub(/\s+/, ''),
year: data['year']).first
end
Exception:
/Users/charlie/Documents/WIP/projectx/ar_models.rb:35:in `find_by_data': undefined method `downcase' for nil:NilClass (NoMethodError)ooooooooooooooooooooooooo| ETA: 0:00:00
from /Users/charlie/.rvm/gems/ruby-2.0.0-p0/gems/activerecord-4.0.0/lib/active_record/relation/delegation.rb:36:in `block in find_by_data'
from /Users/charlie/.rvm/gems/ruby-2.0.0-p0/gems/activerecord-4.0.0/lib/active_record/associations/collection_proxy.rb:845:in `block in scoping'
from /Users/charlie/.rvm/gems/ruby-2.0.0-p0/gems/activerecord-4.0.0/lib/active_record/relation.rb:270:in `scoping'
from /Users/charlie/.rvm/gems/ruby-2.0.0-p0/gems/activerecord-4.0.0/lib/active_record/associations/collection_proxy.rb:845:in `scoping'
from /Users/charlie/.rvm/gems/ruby-2.0.0-p0/gems/activerecord-4.0.0/lib/active_record/relation/delegation.rb:36:in `find_by_data'
from /Users/charlie/Documents/WIP/projectx/ar_models.rb:132:in `create_or_assign_existing'
from /Users/charlie/Documents/WIP/projectx/app.rb:230:in `block (2 levels) in work'
from /Users/charlie/.rvm/gems/ruby-2.0.0-p0/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract/connection_pool.rb:294:in `with_connection'
from /Users/charlie/Documents/WIP/projectx/app.rb:80:in `block in work'
from /Users/charlie/.rvm/gems/ruby-2.0.0-p0/gems/parallel-0.6.3/lib/parallel.rb:319:in `call'
from /Users/charlie/.rvm/gems/ruby-2.0.0-p0/gems/parallel-0.6.3/lib/parallel.rb:319:in `call_with_index'
from /Users/charlie/.rvm/gems/ruby-2.0.0-p0/gems/parallel-0.6.3/lib/parallel.rb:179:in `block (3 levels) in work_in_threads'
from /Users/charlie/.rvm/gems/ruby-2.0.0-p0/gems/parallel-0.6.3/lib/parallel.rb:326:in `with_instrumentation'
from /Users/charlie/.rvm/gems/ruby-2.0.0-p0/gems/parallel-0.6.3/lib/parallel.rb:177:in `block (2 levels) in work_in_threads'
from /Users/charlie/.rvm/gems/ruby-2.0.0-p0/gems/parallel-0.6.3/lib/parallel.rb:171:in `loop'
from /Users/charlie/.rvm/gems/ruby-2.0.0-p0/gems/parallel-0.6.3/lib/parallel.rb:171:in `block in work_in_threads'
from /Users/charlie/.rvm/gems/ruby-2.0.0-p0/gems/parallel-0.6.3/lib/parallel.rb:62:in `block (2 levels) in in_threads'
When you see "undefined method ... for nil:NilClass" it means you have a nil value you're trying to call the method on.
In this case, something like data['name'] is not defined.
To make this more bullet-proof:
data['name'].to_s.downcase.gsub(/\s+/, '')
This converts everything to string to start with. nil.to_s is an empty string by default, so it's safe.
Use ternary oprators perhaps:
def self.find_by_data(data = {})
where(name_canonical: data['name'] == nil ? '' : data['name'].downcase.gsub(/\s+/, ''),
fuel: data['fuel'],
trim_canonical: data['trim'] == nil ? '' : data['name'].downcase.gsub(/\s+/, ''),
year: data['year']).first
end
Your
data['name']
or
data['trim']
is a nil.
Check your input data.

Having trouble with Nokogiri and Rails

Been at this for a while. If i tell Category to just create, everything works fine. If I tell it to find_or_create I get errors.
These work:
puts topic.at_xpath("#topicid")
puts topic.at_xpath("#topicname")
and
Category.create!(:topic_id => topic.at_xpath("#topicid"), :name => topic.at_xpath("#topicname"))
But these don't:
Category.find_by_name(topic.at_xpath("#topicname"))
or
Category.find_or_create_by_topic_id_and_name(topic.at_xpath("#topicid"), topic.at_xpath("#topicname"))
Where am I messing up?
class FeedEntry < ActiveRecord::Base
require 'nokogiri'
require 'open-uri'
has_many :category_feeds
has_many :categories, :through => :category_feeds
accepts_nested_attributes_for :categories, :allow_destroy => true, :reject_if => proc { |obj| obj.blank? }
def self.nokogiri_get_feed
url = "http://some_feed.com/atom_feed"
doc = Nokogiri::HTML(open(url))
doc.remove_namespaces!
doc.search('feed entry').each do |item|
unless exists? :guid => item.css('id').text
create!(:name => item.css('title').text, :summary => item.css('title').text, :url => item.at_css("link")[:href], :published_at => item.css('updated').text, :guid => item.css('id').text)
item.xpath('content').each do |i|
i.css('topic').each do |topic|
id = topic.at_xpath("#topicid")
name = topic.at_xpath("#topicname")
update_attributes!(:categories=>[Category.find_or_create_by_topic_id_and_name(id, name)])
end
end
end
end
end
end
errors are:
ruby-1.9.2-p180 :001 > FeedEntry.nokogiri_get_feed
TypeError: Cannot visit Nokogiri::XML::Attr
from /Users/pca/.rvm/gems/ruby-1.9.2-p180/gems/arel-2.0.9/lib/arel/visitors/visitor.rb:21:in `rescue in visit'
from /Users/pca/.rvm/gems/ruby-1.9.2-p180/gems/arel-2.0.9/lib/arel/visitors/visitor.rb:15:in `visit'
from /Users/pca/.rvm/gems/ruby-1.9.2-p180/gems/arel-2.0.9/lib/arel/visitors/to_sql.rb:260:in `visit_Arel_Nodes_Equality'
from /Users/pca/.rvm/gems/ruby-1.9.2-p180/gems/arel-2.0.9/lib/arel/visitors/visitor.rb:15:in `visit'
from /Users/pca/.rvm/gems/ruby-1.9.2-p180/gems/arel-2.0.9/lib/arel/visitors/to_sql.rb:120:in `visit_Arel_Nodes_Grouping'
from /Users/pca/.rvm/gems/ruby-1.9.2-p180/gems/arel-2.0.9/lib/arel/visitors/visitor.rb:15:in `visit'
from /Users/pca/.rvm/gems/ruby-1.9.2-p180/gems/arel-2.0.9/lib/arel/visitors/to_sql.rb:91:in `block in visit_Arel_Nodes_SelectCore'
from /Users/pca/.rvm/gems/ruby-1.9.2-p180/gems/arel-2.0.9/lib/arel/visitors/to_sql.rb:91:in `map'
from /Users/pca/.rvm/gems/ruby-1.9.2-p180/gems/arel-2.0.9/lib/arel/visitors/to_sql.rb:91:in `visit_Arel_Nodes_SelectCore'
from /Users/pca/.rvm/gems/ruby-1.9.2-p180/gems/arel-2.0.9/lib/arel/visitors/to_sql.rb:77:in `block in visit_Arel_Nodes_SelectStatement'
from /Users/pca/.rvm/gems/ruby-1.9.2-p180/gems/arel-2.0.9/lib/arel/visitors/to_sql.rb:77:in `map'
from /Users/pca/.rvm/gems/ruby-1.9.2-p180/gems/arel-2.0.9/lib/arel/visitors/to_sql.rb:77:in `visit_Arel_Nodes_SelectStatement'
from /Users/pca/.rvm/gems/ruby-1.9.2-p180/gems/arel-2.0.9/lib/arel/visitors/sqlite.rb:7:in `visit_Arel_Nodes_SelectStatement'
from /Users/pca/.rvm/gems/ruby-1.9.2-p180/gems/arel-2.0.9/lib/arel/visitors/visitor.rb:15:in `visit'
from /Users/pca/.rvm/gems/ruby-1.9.2-p180/gems/arel-2.0.9/lib/arel/visitors/visitor.rb:5:in `accept'
from /Users/pca/.rvm/gems/ruby-1.9.2-p180/gems/arel-2.0.9/lib/arel/visitors/to_sql.rb:19:in `block in accept' ... 11 levels...
from /Users/pca/.rvm/gems/ruby-1.9.2-p180/gems/nokogiri-1.4.4/lib/nokogiri/xml/node_set.rb:238:in `each'
from /Users/pca/projects/cdapp/cdrails/app/models/feed_entry.rb:35:in `block (2 levels) in nokogiri_get_feed'
from /Users/pca/.rvm/gems/ruby-1.9.2-p180/gems/nokogiri-1.4.4/lib/nokogiri/xml/node_set.rb:239:in `block in each'
from /Users/pca/.rvm/gems/ruby-1.9.2-p180/gems/nokogiri-1.4.4/lib/nokogiri/xml/node_set.rb:238:in `upto'
from /Users/pca/.rvm/gems/ruby-1.9.2-p180/gems/nokogiri-1.4.4/lib/nokogiri/xml/node_set.rb:238:in `each'
from /Users/pca/projects/cdapp/cdrails/app/models/feed_entry.rb:33:in `block in nokogiri_get_feed'
from /Users/pca/.rvm/gems/ruby-1.9.2-p180/gems/nokogiri-1.4.4/lib/nokogiri/xml/node_set.rb:239:in `block in each'
from /Users/pca/.rvm/gems/ruby-1.9.2-p180/gems/nokogiri-1.4.4/lib/nokogiri/xml/node_set.rb:238:in `upto'
from /Users/pca/.rvm/gems/ruby-1.9.2-p180/gems/nokogiri-1.4.4/lib/nokogiri/xml/node_set.rb:238:in `each'
from /Users/pca/projects/cdapp/cdrails/app/models/feed_entry.rb:30:in `nokogiri_get_feed'
from (irb):1
from /Users/pca/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.3/lib/rails/commands/console.rb:44:in `start'
from /Users/pca/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.3/lib/rails/commands/console.rb:8:in `start'
from /Users/pca/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.3/lib/rails/commands.rb:23:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'
Summary
Instead of these lines:
id = topic.at_xpath("#topicid")
name = topic.at_xpath("#topicname")
Use these instead:
id = topic['topicid']
name = topic['topicname']
Explanation
Let's look at a simple test case:
require 'nokogiri'
xml = Nokogiri::XML("<root foo='bar' />")
foo = xml.root.at_xpath('#foo')
puts foo
#=> bar
p foo
#=> #<Nokogiri::XML::Attr:0x15c1d64 name="foo" value="bar">
p foo.text
#=> "bar"
p xml.root['foo']
#=> "bar"
As you can see from the above, selecting an attribute via XPath actually gives you an Attr node, which is not the same as the string value of that attribute. (Using puts causes the to_s method of the Attr to show you only the value, but that doesn't mean that it's actually a string.)
As shown above, you need to use the text method (or value or content) on the Attr nodes to get the string value back that you really wanted:
id = topic.at_xpath("#topicid").text
name = topic.at_xpath("#topicname").text
Alternatively (and more simply) use the Element#[] method to fetch the value of an attribute off of an element directly:
id = topic['topicid']
name = topic['topicname']

Resources