I have this:
def some_method()
if auto_pagination
customers_list.auto_paging_each do |customer|
customer_hash = importer.extract(customer)
arr << customer_hash
end
else
customers_list.each do |customer|
customer_hash = importer.extract(customer)
arr << customer_hash
end
end
end
I would like to refactor it in a shorter version. I though about send method but with the block I turns out a bit tricky. Any ideas?
I though about send method but with the block I turns out a bit tricky
I'm not sure what you mean by "tricky", but:
def some_method()
method_name = auto_pagination ? :auto_paging_each : :each
customers_list.send(method_name) do |customer|
customer_hash = importer.extract(customer)
arr << customer_hash
end
end
Related
When I run code below it raise error:
implicit argument passing of super from method defined by define_method() is not supported. Specify all arguments explicitly. (RuntimeError).
I am not sure what is the problem.
class Result
def total(*scores)
percentage_calculation(*scores)
end
private
def percentage_calculation(*scores)
puts "Calculation for #{scores.inspect}"
scores.inject {|sum, n| sum + n } * (100.0/80.0)
end
end
def mem_result(obj, method)
anon = class << obj; self; end
anon.class_eval do
mem ||= {}
define_method(method) do |*args|
if mem.has_key?(args)
mem[args]
else
mem[args] = super
end
end
end
end
r = Result.new
mem_result(r, :total)
puts r.total(5,10,10,10,10,10,10,10)
puts r.total(5,10,10,10,10,10,10,10)
puts r.total(10,10,10,10,10,10,10,10)
puts r.total(10,10,10,10,10,10,10,10)
The error message is quite descriptive. You need to explicitly pass arguments to super when you call it inside of define_method block:
mem[args] = super(*args)
I have a method in spec\factories\campaigns.rb:
def campaign_trait(name, *callback_attrs, &block)
trait name do
association :campaign_type, factory: [:campaign_type, name]
after(:build) do |campaign, evaluator|
eval_str = ""
callback_attrs.each do |arg|
arg = [arg] unless arg.is_a? Array
method_name = arg.shift
method_args = arg
method_name = "add_#{method_name}" unless respond_to? method_name
eval_str << method_name.to_s
eval_str << "(campaign"
eval_str << ", evaluator" if method_name == "add_campaign_scopes"
if method_args.any?
method_args.map! { |i| i.is_a?(Symbol) ? ":#{i}" : i }
eval_str << ", " << method_args.map(&:to_s).join(', ')
end
eval_str << ")\n"
end
eval eval_str
end
yield(block) if block_given?
end
end
I call it here:
FactoryGirl.define do
campaign_trait :basket, :campaign_scopes, [:banner, :basket] do
initialize_with { Campaigns::Basket.new(attributes, without_protection: true) }
emitent_article 'emitent'
emitent_name 'Emitent'
end
end
The problem that I face is that in the method campaign_trait I get callback_attrs that equals [:campaign_scopes, []] instead of expected [:campaign_scopes, [:banner, :basket]].
If I call campaign_trait without the block, everything is OK and I get [:campaign_scopes, [:banner, :basket]] as expected.
Could you please help me?
The problem was that I was calling campaign_trait number of times through many tests and somehow (I don't know why), callback_attrs are shared between tests. And method_name = arg.shift breaks my code modifying callback_attrs.
Thanks, BroiSatse! Deep debugging helped me.
I have this class:
class Items
def initialize &block
(block.arity < 1 ? (instance_eval &block) : block.call(self)) if block_given?
end
def button_id button_id=nil
unless #button_id.present?
raise "button_id must be supplied" if button_id.nil?
#button_id = button_id
end
#button_id
end
end
Now, when I do this it works:
Items.new do
button_id 1
end
But when I do this, it fails because I think it is not on the same scope:
#button = Button.find(params[:button_id]
Items.new do
button_id #button.id
end
How can fix this to take arguments outside the scope?
Thanks!
Try this:
class Items
def self.dsl
new.tap do |item|
yield item
end
end
def button_id(button_id)
#button_id = button_id
end
end
#button = Button.find(params[:button_id])
item = Items.dsl do |item|
item.button_id(#button.id)
end
puts item.inspect
Turns out all I needed to do was to pass the arguments to the block like this:
Items.new do |item|
item.button_id #button.id
end
Less beautiful DSL but works.
I don't think this is the right use case of DSL, when you can simply assign the attributes by arguments.
class Item
attr_accessor: :button_id
def initialize(args)
button_id = args[:button_id]
end
end
Another problem is in your usage. The instance would be of little value if you don't assign it to a variable
item = Item.new button_id: button_id
When I run code below it raise error:
implicit argument passing of super from method defined by define_method() is not supported. Specify all arguments explicitly. (RuntimeError).
I am not sure what is the problem.
class Result
def total(*scores)
percentage_calculation(*scores)
end
private
def percentage_calculation(*scores)
puts "Calculation for #{scores.inspect}"
scores.inject {|sum, n| sum + n } * (100.0/80.0)
end
end
def mem_result(obj, method)
anon = class << obj; self; end
anon.class_eval do
mem ||= {}
define_method(method) do |*args|
if mem.has_key?(args)
mem[args]
else
mem[args] = super
end
end
end
end
r = Result.new
mem_result(r, :total)
puts r.total(5,10,10,10,10,10,10,10)
puts r.total(5,10,10,10,10,10,10,10)
puts r.total(10,10,10,10,10,10,10,10)
puts r.total(10,10,10,10,10,10,10,10)
The error message is quite descriptive. You need to explicitly pass arguments to super when you call it inside of define_method block:
mem[args] = super(*args)
I am working on an events application where i want to filter events depending on the 3 parameters location or starts_at or ends_at in the query string. There can be any one, two or all the parameters in the query string. In i use if-else statement i need to make 6 cases which will make my code clumsy. Rather i am thinking to implement something this way:
class EventsController < ApplicationController
def index
unless params.empty?
unless params[:location].nil?
#events = Event.where("location = ?", params[:location])
end
unless params[:starts_at].nil?
unless #events.empty?
#events = #events.where("start_date = ?", params[:start_date])
else
#events = Event.where("Date(starts_at) = Date(?)", params[:starts_at])
end
end
unless params[:ends_at].nil?
unless #events.empty?
#events = #events.where("end_date = ?", params[:end_date])
else
#events = Event.where("Date(ends_at) = Date(?)", params[:ends_at])
end
end
end
end
end
But this code doesnt work since where query doen not work on an array. Can someone suggest me some solution for this..
You should be able to pass your params hash directly to where, and it will form the correct SQL based on the keys and values of that hash:
Event.where(params)
An example in the console:
1.9.3p194 :001 > puts Example.where(:location => 'here', :started_at => '2012-08-13').to_sql
SELECT "examples".* FROM "examples" WHERE "examples"."location" = 'here' AND "examples"."started_at" = '2012-08-13'
Try Following
def index
unless params.empty?
where_array, arr = [], []
if params[:location]
where_array << "location = ?"
arr << params[:location]
end
if params[:starts_at]
where_array << "start_date = ?"
arr << params[:starts_at]
end
if params[:ends_at]
where_array << "end_date = ?"
arr << params[:ends_at]
end
#events = arr.blank? ? [] : Event.where([where_array.join(" AND "), *arr])
end
end