Calling class methods
To call a class method (or static method) from an instance method:
class.method()
To call a class method from a class method:
method()
Related cards:
Fixing "A copy of Klass has been removed from the module tree but is still active"
This can happen during development when classes without automatic reloading are pointing to classes with automatic reloading. E.g. some class in lib is calling Model.static_method.
Workaround A
Stop referencing autoloaded classes fro...
Defining class methods with Modularity traits
There are two ways to define a class method from a Modularity trait. Note that the [usual caveats regarding class method visibility](https://makandracards.com/makandra/17795-the-private-modifier-does-not-a...
Stubbed class methods in RSpec 1 remain stubbed in other examples
I encountered a bug in RSpec 1.x where stubbed class methods ("static methods") would not be unstubbed before the next example, causing it to fail. This behavior can come and go as you edit your specs, since this can change the order in which RSpe...
Class methods in Coffeescript
How to define and call class methods in CoffeeScript classes:
class Foo
@classMethod: ->
@otherClassMethod()
instanceMethod: ->
@otherInstanceMethod()
@constructor.classMethod()
The many gotchas of Ruby class variables
TLDR: Ruby class variables (@@foo) are dangerous in many ways. You should avoid them at all cost. See bottom of this card for alternatives.
Class variables are shared between a class hierarchy
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Rails: When defining scopes with class methods, don't use `self`
Sometimes it is useful to define a named scope by implementing a static method with the scope's name on the scoped class. For instance, when a method should decide which existing scope should be the next link in the scope chain. Take this class fo...
Why Ruby Class Methods Resist Refactoring
In a nutshell:
- Splitting a long method into sub methods is easier in instances since it is in classes. Since you must not save state in a class, you need to pass around context as a long chain of parameters again and again.
- If your public API...
How to call overwritten methods of parent classes in Backbone.js
When you are working with Backbone models and inheritance, at some point you want to overwrite inherited methods but call the parent's implementation, too.
In JavaScript, there is no simple "super" method like in Ruby -- so here is how to do it ...
You can use graphs in gitlab comments!
Since GitLab 10.3. you can use Mermaid in GitLab comments: Gitlab Doc.
With Mermaid you can create diagrams based on text / code.
...
The Ruby Object Model
In Ruby (almost) everything is an Object. While this enables a lot of powerful features, this concept might be confusing for developers who have been programming in more static languages, such as Java or C#. This card should help understanding t...