Top "Observer-pattern" questions

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.

Scala Listener/Observer

Typically, in Java, when I've got an object who's providing some sort of notification to other objects, I'll employ the …

scala listener observer-pattern
Getting "deallocated while key value observers were still registered with it." errors after conversion to ARC

I am using this class: https://github.com/alexleutgoeb/ALPickerView Since I converted to ARC, I get this error after …

ios cocoa-touch observer-pattern dealloc automatic-ref-counting
Stopping product saving process in observer

I am currently developing a module working with the product edit in the backend. Its purpose is to retrieve categories …

php magento save observer-pattern abort
Good way to have a Collection Listener?

Is there a better way to have a listener on a java collection than wrap it in a class implementing …

java collections listener observer-pattern
Magento AddAttributeToSelect() on custom added attribute (observer)

I have set up an observer on catalog_product_collection_load_after and the following code is called: <?php …

observer-pattern magento-1.5 magento
Is an EventListener an Observable?

I am currently following a class about Design Patterns and was wondering whether an EventListener is an Observable? I don't …

design-patterns observer-pattern event-listener observable
Observe a File or Folder in Objective-C

What is the best way to listen to a folder or file to see if it has been saved or …

objective-c cocoa observer-pattern
Magento - customer_save_after always fired twice

I am using the customer_save_after event in magento, and all is working fine apart from 1 annoying thing - …

php events magento observer-pattern
Observable/Observer not working?

I tried implementing a static Observable in my Application subclass, but it's not working. No exceptions or error messages, but …

java android observer-pattern observable observers
Is Eventbus a Mediator or Observer Pattern?

Is Eventbus more a Mediator or an Observer? According to Google, "eventbus mediator" gets 2.430 hits and "eventbus observer" gets 3.850 hits. …

design-patterns observer-pattern event-bus mediator