mixins

I'm trying to reuse a helper method in all my factories, however I cannot get it to work. Here's my setup: Helper module (in spec/support/test_helpers.rb) module Tests module Helpers # not guaranteed to be unique, useful for generating passwords def random_string(length = 20) chars = ['A'..'Z', 'a'..'z', '0'..'9'].map{|r|r.to_a}.flatten (0...length).map{ chars[rand(chars.size)] }.join end end end A factory (in spec/factories/users.rb) FactoryGirl.define do factory :user do sequence(:username) { |n| "username-#{n}" } password random_string password_confirmation { |u| u.password } end end If I

In studying mixins vs. dependency injection, I often hear the phrase "the Ruby way." Often developers say something along the lines of Ruby lets you reopen classes and redefine methods means that you can easily "inject" new references into your code at test-time. (see #6 at http://weblog.jamisbuck.org/2007/7/29/net-ssh-revisited ) But testing is not my main concern; my concern is class reuse. I want classes I can reuse in multiple enterprise-scale Rails applications. So what happened to REUSING classes? Using mixins and reopening classes does not seem to provide a way to write classes in such

Is there any clean way to initialize instance variables in a Module intended to be used as Mixin? For example, I have the following: module Example def on(...) @handlers ||= {} # do something with @handlers end def all(...) @all_handlers ||= [] # do something with @all_handlers end def unhandled(...) @unhandled ||= [] # do something with unhandled end def do_something(..) @handlers ||= {} @unhandled ||= [] @all_handlers ||= [] # potentially do something with any of the 3 above end end Notice that I have to check again and again if each @member has been properly initialized in each function --

I'm trying to make a LESS mixin that will give me this output: .resource:nth-child(8n+1) { clear: left; } I've got this so far: .wrap-every(@n) { &:nth-child(@n + "n+1") { // parse error on this line clear: left; } } .resource { .wrap-every(8); } But it's giving a parse error on the indicated line ParseError: Unrecognised input Is there a way to do this? Less >= 1.4 you could do something like this: .wrap-every(@n) { &:nth-child(@{n}n + 1) { clear: left; } } this should have the desired output. Without any hacks needed. in older versins of Less you can try simple string interpolation : .wrap

I am trying to implement an EventEmitter/Subscriber relationship between two components in a react native class. I have seen referenced the following materials: React Native - Event Emitters by Colin Ramsay React Native - Call Function of child from NavigatorIOS These solutions are adequate for what I am trying to accomplish, however, they bother require the use of mixins: [Subscribable.Mixin] on the receiving component to work properly with Subscriber . Unfortunately, I am using ES6 and extending my classes from Component so I can not use this mixin syntax. My question is: How can I implement

So, I think the code probably explains what I'm trying to do better than I can in words, so here goes: import abc class foo(object): __metaclass__ = abc.ABCMeta @abc.abstractmethod def bar(self): pass class bar_for_foo_mixin(object): def bar(self): print "This should satisfy the abstract method requirement" class myfoo(foo, bar_for_foo_mixin): def __init__(self): print "myfoo __init__ called" self.bar() obj = myfoo() The result: TypeError: Can't instantiate abstract class myfoo with abstract methods bar I'm trying to get the mixin class to satisfy the requirements of the abstract/interface