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)
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'm trying my first foray into metaprogramming and it's not going very well! It's a Rails 4.1 application and I'm trying to refactor an active record model (User) to combine two methods that are very similar. The original methods are slightly complex DB calls and work as expected.
The original code:
def retweet_count(league)
celebrity_ids = Roster.
where("user_id = ? and league_id = ?", self.id, league.id).
select(:celebrity_id).map { |r| r.celebrity_id }
Tweet.where({
tweet_date: league.start_date..league.end_date,
celebrity_id: celebrity_ids
}).select(:retweet_count).inject(0) do |sum, n|
sum + ( n.retweet_count || 0 )
end
end
def favorite_count(league)
celebrity_ids = Roster.
where("user_id = ? and league_id = ?", self.id, league.id).
select(:celebrity_id).map { |r| r.celebrity_id }
Tweet.where({
tweet_date: league.start_date..league.end_date,
celebrity_id: celebrity_ids
}).select(:favorite_count).inject(0) do |sum, n|
sum + ( n.favorite_count || 0 )
end
end
The new code:
twitter_stats_count :retweet, :favorite
private
def twitter_stats_count(*stats)
stats.each do |statistic|
stat = send(statistic).to_s
define_method "#{stat}_count" do |league|
celebrity_ids = Roster.
where("user_id = ? and league_id = ?", self.id, league.id).
select(:celebrity_id).map { |r| r.celebrity_id }
Tweet.where({
tweet_date: league.start_date..league.end_date,
celebrity_id: celebrity_ids
}).select("#{stat}_count").inject(0) do |sum, n|
sum + ( n.send("#{stat}_count") || 0 )
end
end
end
end
The error the new code produces when I try to start my rails server:
/Users/kiddo/.rvm/gems/ruby-2.1.0/gems/activerecord-4.1.0.rc2/lib/active_record/dynamic_matchers.rb:26:in `method_missing': undefined method `twitter_stats_count' for User (call 'User.connection' to establish a connection):Class (NoMethodError)
I can't seem to figure out what I'm doing wrong, so any pointers would be much appreciated!
FYI, here's the final code I got working. I mainly went with Holger Just's suggestions, but incorporated aspects from several others, so upvotes all around!
def team_ids(league)
Roster.where(user_id: self.id, league_id: league.id).pluck(:celebrity_id)
end
def self.twitter_stats_count(*stats)
stats.each do |statistic|
stat = statistic.to_s
define_method "#{stat}_count" do |league|
Tweet.where({
tweet_date: league.start_date..league.end_date,
celebrity_id: self.team_ids(league)
}).sum("#{stat}_count")
end
end
end
twitter_stats_count :retweet, :favorite
There are a couple of issues with your approach:
You call the twitter_stats_count directly on the class, not an instance of the class. As such, the method needs to be a class method. You can define it as a class method with
def self.twitter_stats_count(*stats)
# ...
end
Additionally, you call the method before having it defined. In Ruby, everything (even method definitions) are executed. As such, you can only call methods after they have been defined. Thus, you need to put the call to your twitter_stats_count method after its definition.
That looks quite complicated. If I'm not mistaken, you can reduce the duplication by refactoring your code:
def retweet_count(league)
league_tweets(league).sum(:retweet_count)
end
def favorite_count(league)
league_tweets(league).sum(:favorite_count)
end
def celebrity_ids(league)
Roster.where(user_id: self.id, league_id: league.id).pluck(:celebrity_id)
end
def league_tweets(league)
Tweet.where(
tweet_date: league.start_date..league.end_date,
celebrity_id: celebrity_ids(league)
)
end
twitter_stats_count should be a class method, but what you did is make it a instance method, maybe you can try this:
# no private here
def self.twitter_stats_count(*status)
#your codes here
end
You are getting this error because, you have define twitter_stats_count as a private method, You can't call this on self. You have to put it in a instance method, than call it.
Check this.
For example following gives same error:
class Foo
baz
private
def baz
puts "baz called"
end
end
However this will work:
class Foo
def dummy
baz
end
private
def baz
puts "baz called"
end
end
foo = Foo.new
foo.dummy
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
Here's how some of my existing logging code with Log4r is working. As you can see in the WorkerX::a_method, any time that I log a message I want the class name and the calling method to be included (I don't want all the caller history or any other noise, which was my purpose behind LgrHelper).
class WorkerX
include LgrHelper
def initialize(args = {})
#logger = Lgr.new({:debug => args[:debug], :logger_type => 'WorkerX'})
end
def a_method
error_msg("some error went down here")
# This prints out: "WorkerX::a_method - some error went down here"
end
end
class Lgr
require 'log4r'
include Log4r
def initialize(args = {}) # args: debug boolean, logger type
#debug = args[:debug]
#logger_type = args[:logger_type]
#logger = Log4r::Logger.new(#logger_type)
format = Log4r::PatternFormatter.new(:pattern => "%l:\t%d - %m")
outputter = Log4r::StdoutOutputter.new('console', :formatter => format)
#logger.outputters = outputter
if #debug then
#logger.level = DEBUG
else
#logger.level = INFO
end
end
def debug(msg)
#logger.debug(msg)
end
def info(msg)
#logger.info(msg)
end
def warn(msg)
#logger.warn(msg)
end
def error(msg)
#logger.error(msg)
end
def level
#logger.level
end
end
module LgrHelper
# This module should only be included in a class that has a #logger instance variable, obviously.
protected
def info_msg(msg)
#logger.info(log_intro_msg(self.method_caller_name) + msg)
end
def debug_msg(msg)
#logger.debug(log_intro_msg(self.method_caller_name) + msg)
end
def warn_msg(msg)
#logger.warn(log_intro_msg(self.method_caller_name) + msg)
end
def error_msg(msg)
#logger.error(log_intro_msg(self.method_caller_name) + msg)
end
def log_intro_msg(method)
msg = class_name
msg += '::'
msg += method
msg += ' - '
msg
end
def class_name
self.class.name
end
def method_caller_name
if /`(.*)'/.match(caller[1]) then # caller.first
$1
else
nil
end
end
end
I really don't like this approach. I'd rather just use the existing #logger instance variable to print the message and be smart enough to know the context. How can this, or similar simpler approach, be done?
My environment is Rails 2.3.11 (for now!).
After posting my answer using extend, (see "EDIT", below), I thought I'd try using set_trace_func to keep a sort of stack trace like in the discussion I posted to. Here is my final solution; the set_trace_proc call would be put in an initializer or similar.
#!/usr/bin/env ruby
# Keep track of the classes that invoke each "call" event
# and the method they called as an array of arrays.
# The array is in the format: [calling_class, called_method]
set_trace_func proc { |event, file, line, id, bind, klass|
if event == "call"
Thread.current[:callstack] ||= []
Thread.current[:callstack].push [klass, id]
elsif event == "return"
Thread.current[:callstack].pop
end
}
class Lgr
require 'log4r'
include Log4r
def initialize(args = {}) # args: debug boolean, logger type
#debug = args[:debug]
#logger_type = args[:logger_type]
#logger = Log4r::Logger.new(#logger_type)
format = Log4r::PatternFormatter.new(:pattern => "%l:\t%d - %m")
outputter = Log4r::StdoutOutputter.new('console', :formatter => format)
#logger.outputters = outputter
if #debug then
#logger.level = DEBUG
else
#logger.level = INFO
end
end
def debug(msg)
#logger.debug(msg)
end
def info(msg)
#logger.info(msg)
end
def warn(msg)
#logger.warn(msg)
end
def error(msg)
#logger.error(msg)
end
def level
#logger.level
end
def invoker
Thread.current[:callstack] ||= []
( Thread.current[:callstack][-2] || ['Kernel', 'main'] )
end
end
class CallingMethodLogger < Lgr
[:info, :debug, :warn, :error].each do |meth|
define_method(meth) { |msg| super("#{invoker[0]}::#{invoker[1]} - #{msg}") }
end
end
class WorkerX
def initialize(args = {})
#logger = CallingMethodLogger.new({:debug => args[:debug], :logger_type => 'WorkerX'})
end
def a_method
#logger.error("some error went down here")
# This prints out: "WorkerX::a_method - some error went down here"
end
end
w = WorkerX.new
w.a_method
I don't know how much, if any, the calls to the proc will affect the performance of an application; if it ends up being a concern, perhaps something not as intelligent about the calling class (like my old answer, below) will work better.
[EDIT: What follows is my old answer, referenced above.]
How about using extend? Here's a quick-and-dirty script I put together from your code to test it out; I had to reorder things to avoid errors, but the code is the same with the exception of LgrHelper (which I renamed CallingMethodLogger) and the second line of WorkerX's initializer:
#!/usr/bin/env ruby
module CallingMethodLogger
def info(msg)
super("#{#logger_type}::#{method_caller_name} - " + msg)
end
def debug(msg)
super("#{#logger_type}::#{method_caller_name} - " + msg)
end
def warn(msg)
super("#{#logger_type}::#{method_caller_name} - " + msg)
end
def error(msg)
super("#{#logger_type}::#{method_caller_name} - " + msg)
end
def method_caller_name
if /`(.*)'/.match(caller[1]) then # caller.first
$1
else
nil
end
end
end
class Lgr
require 'log4r'
include Log4r
def initialize(args = {}) # args: debug boolean, logger type
#debug = args[:debug]
#logger_type = args[:logger_type]
#logger = Log4r::Logger.new(#logger_type)
format = Log4r::PatternFormatter.new(:pattern => "%l:\t%d - %m")
outputter = Log4r::StdoutOutputter.new('console', :formatter => format)
#logger.outputters = outputter
if #debug then
#logger.level = DEBUG
else
#logger.level = INFO
end
end
def debug(msg)
#logger.debug(msg)
end
def info(msg)
#logger.info(msg)
end
def warn(msg)
#logger.warn(msg)
end
def error(msg)
#logger.error(msg)
end
def level
#logger.level
end
end
class WorkerX
def initialize(args = {})
#logger = Lgr.new({:debug => args[:debug], :logger_type => 'WorkerX'})
#logger.extend CallingMethodLogger
end
def a_method
#logger.error("some error went down here")
# This prints out: "WorkerX::a_method - some error went down here"
end
end
w = WorkerX.new
w.a_method
The output is:
ERROR: 2011-07-24 20:01:40 - WorkerX::a_method - some error went down here
The downside is, via this method, the caller's class name isn't automatically figured out; it's explicit based on the #logger_type passed into the Lgr instance. However, you may be able to use another method to get the actual name of the class--perhaps something like the call_stack gem or using Kernel#set_trace_func--see this thread.