`return $this;` design pattern or anti-pattern?

Question

I've seen many times Zend Framework using return $this; pattern style - and from my point of view:

• Pro: seems its quite not bad pattern style for chaining many actions on the same object and making your code shorter.

• Con: code looks a bit weird when you see that object returns itself in the method, which does something else (e.g. setter for some property)

Is it really good pattern practice or maybe an anti-patternpractice?

EDIT: well it was a little too much from my side to call it "pattern", thanks everyone for pointing me to right direction!

Answer 1

I've found method chaining to be useful in circumstances where it makes sense; a domain specific language, for example:

$query->select('*')->from('users')->where(array('user_id' => 1, 'verified' => 1));

The thing is, these methods would only be returning void anyway and so the return $this merely functions as a short hand version of writing:

$query->select('*'); $query->from('users'); $query->where(...);

We're still going to be calling the toSQL() or execute() method to make use of the data we've populated our object with.

In my opinion it is not an anti-pattern and can function as a legitimate, sensible, method of object population in the right circumstances.