A design pattern in which an object, called the subject, maintains a list of its dependents, called observers and notifies them automatically of any state changes, usually by calling one of their methods.
We recently began a compliance push at our company and are required to keep a full history of changes to …
ruby-on-rails ruby activerecord observer-patterni thought about using observers or callbacks. What and when you should use an observer? F.e. you could do …
ruby-on-rails callback observer-patternI come from a C# background, and have just started programming in Ruby. The thing is, that I need to …
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java events observer-pattern observableI am trying to make sense of Observer design pattern as the main event dispatching design pattern. The Observer pattern …
design-patterns observer-pattern publish-subscribe event-dispatchingRecently I heard the term reactive programming a lot, but when I searched for it, what I discovered was only …
observer-pattern reactive-programmingThe java.util.Observer and java.util.Observable are ugly. They require the sorts of casts that make type-safety fans …
java generics observer-patternI'm writing an observer that check every item in a order, at some point I get the items foreach($order-&…
php magento observer-patternI'm using restful_authentication in my app. I'm creating a set of default users using a rake task, but every …
ruby-on-rails ruby observer-pattern restful-authenticationI'm trying to understand the Observer and the Observable. Here's an example that I'm trying to figure out: public class …
java oop design-patterns observer-pattern