Advantages and drawbacks of chainable methods?

Question

I really love the philosophy of chaining methods, like jQuery emphasys in its library. I found it quite elegant and clear.

Being primarily Java developper, I've always wondering myself why this practice was not more used in this language. For example, the Collection interface was not designed in the that way (for adding/removing methods), and I found it quite sad.

Is there real cons against this practice or is it just something that has not enough "sex-appeal" before?

Answer 1

IMO it is painful to debug as you tend to have no intermediary variables for inspection.

Answer 2

There's a common problem with chainable methods and inheritance. Assume you have a class C whose methods F1(), F2(), etc. return a C. When you derive class D from C, you want the methods F1, F2, etc to now return a D so that D's chainable methods can be called anywhere in the chain.

Answer 3

I really like this approach as well. The only downside I can think of is that it seems a bit awkward at times to 'return this' at the end of every method. For JQuery, for example, it makes it slightly awkward to allow plugins, because you have to say "make sure you don't forget your returns!!" but there's no good way to catch it at compile time.