are "on" events possible with PHP?

[sfullman]

if you're reading this you know javascript can have fucntions bound to events like onchange or onsubmit etc.

I know you can fork off a new process in PHP, but have never done it. but now I have a very specific question on another concept:

Is there any way to have a resident function running parallel to a ascript, not actually referenced in the coding, which can read the global variables and "interject itself" when certain conditions apply?

for example, suppose I have a script which is building an array. Sure, each time I'm building an array I could add to the loop:

if(is_too_big($array)) {
   //do something
}

but I would like to define a "listener" for a defined event like "ongettoobig" so that, without actual coding, the attached function would fire off as soon as we did:

$biglist[]='one more item here';

and count($biglist) exceeded a defined limit.

For those of you who first ask "why do you want to do this?" vs. simply "yes it's possible" or "no, it's not", I would like to allow "add-ons" to be put into an application where the coding of logic through a script to ask every single logical question (if addon x is installed, then here..) would get cumbersome.

I hope this is explained well, thank you and let me know.

Samuel

[dagon]

In short, no.

[messels]

dagon;10931331 wrote:

In short, no.

lol. that is the short answer.

you can connect everything with javascript and create asynchronous querys to the db (aka AJAX). you essentially use http_request() to do that. so in a WAY you can have listeners--but they are javascript based...so for what you're looking to do it's better to just use javascript and forget about the php. it'd be more code than is necessary.

[johanafm]

If I've understood you correctly, what you're looking for is the "observer" design pattern, or the related "publish/subscribe" pattern. A web search should provide more than enough hits 🙂