I run into really interesting problem with ruby today. I have a module/rails concern :
今天我遇到了红宝石真正有趣的问题。我有一个模块/轨道问题:
module BreakCacheModule
extend ActiveSupport::Concern
module ClassMethods
def breakable_cache_for(method_name, &block)
method_name = method_name.to_sym
set_breakable_cache_proc(method_name, block)
define_breakable_cache_method(method_name)
end
def define_breakable_cache_method(method_name)
instance_eval(
"def #{method_name}
# here will be Rails.cache.fetch block around line below once I figure out this problem
@_break_cache_procs[#{method_name}].call # !!! this line will cause an issue
end"
)
end
def set_breakable_cache_proc(method_name, block)
@_break_cache_procs ||={}
@_break_cache_procs.merge!({method_name => block})
@_break_cache_procs
end
end
end
and in my model
在我的模型中
class Client < ActiveRecord::Base
include BreakCacheModule
breakable_cache_for :all_client_ids do
Client.pluck :id
end
end
so sofar so good but once I go into console (Or run my spec) problems will show up
这么好,但一旦我进入控制台(或运行我的规格)问题将出现
Client.all_client_ids
# SystemStackError: stack level too deep
but when I do:
但当我这样做时:
Client.instance_variable_get("@_break_cache_procs")[:all_client_ids].call
#=> [1,2,3]
The functionality is exactly the same, only difference is that I'm not calling proc from instance_eval.
功能完全相同,唯一的区别是我没有从instance_eval调用proc。
Am I missing something ??
我错过了什么?
my ruby ruby-2.0.0-p247 and Rails 3.2.14
我的ruby ruby-2.0.0-p247和Rails 3.2.14
Thank you for help
谢谢你的帮助
Update after accepting
接受后更新
Just to sum this up, I was getting actually this error from two places:
总而言之,我从两个地方得到了这个错误:
"def #{method_name}
Rails.cache.fetch(#{method_name.to_s}) do # method_name should be in quotes
@_break_cache_procs[#{method_name}].call # missing colon ...look on answer
end
end"
so the code should look like this
所以代码看起来应该是这样的
instance_eval(
"def #{method_name}
Rails.cache.fetch('#{method_name.to_s}') do
@_break_cache_procs[:#{method_name}].call
end
end"
)
1 个解决方案
#1
3
The string passed to instance_eval
is actually:
传递给instance_eval的字符串实际上是:
"def all_client_ids
@_break_cache_procs[all_client_ids].call
end"
You may have noticed the problem: a colon is missing.
您可能已经注意到了这个问题:缺少冒号。
This should be the correct code:
这应该是正确的代码:
def define_breakable_cache_method(method_name)
instance_eval(
"def #{method_name}
# here will be Rails.cache.fetch block around line below once I figure out this problem
@_break_cache_procs[:#{method_name}].call # !!! this line will cause an issue
end"
)
end
#1
3
The string passed to instance_eval
is actually:
传递给instance_eval的字符串实际上是:
"def all_client_ids
@_break_cache_procs[all_client_ids].call
end"
You may have noticed the problem: a colon is missing.
您可能已经注意到了这个问题:缺少冒号。
This should be the correct code:
这应该是正确的代码:
def define_breakable_cache_method(method_name)
instance_eval(
"def #{method_name}
# here will be Rails.cache.fetch block around line below once I figure out this problem
@_break_cache_procs[:#{method_name}].call # !!! this line will cause an issue
end"
)
end