Chaining in PHP
I was just flicking through Tweetdeck when I noticed a tweet by @F1LT3R that was a link to a pastebin snippet. I was curious, so I followed the link and was presented with the following code:
If (isset($resistance) && $resistance->leader == "John Connor") {
$resistanceDeath = $TemporalEngine->SetTimeCoords(strtotime('Birth of John Connor'))->AcquireSubject(new Terminator)->Transport();
}
if (!$resistanceDeath) {
$resistanceDeath = $TemporalEngine->SetTimeCoords(strtotime('Birth of John Connor + 12 years'))->AcquireSubject(new Terminator)->Transport();
}
Now that's quite entertaining on it's own, but it got me thinking. I love how you can chain items in jQuery, and I was wondered if it would work in PHP. A quick test showed me that it would! Not too sure how useful it'd be, but it's quite interesting all the same. Here's my quick mockup code:
class chain {
function setStr($s){
$this->s = $s;
$this->response = $s;
return $this;
}
function length(){
$this->response = strlen($this->s);
return $this;
}
}
$c = new chain();
echo $c->setStr("HEH")->length()->response;
It's a very trivial example, but I'm sure someone out there would be able to think of a use for it.
Related posts:
Technically this is more something you can do with objects rather than just PHP. Same thing will work in Objective-C or Ruby for instance. (And in fact is quite prevalent in both languages.)
There is a hidden advantage to this too – returning the object from all its methods forces you to use proper exception throwing to handle errors, because you can no longer return a special value to indicate errors. However in PHP the built in functions don’t throw exceptions, so you have to detect their return values and throw exceptions yourself.