Re: __autoload() enhancement

From: Date: Sun, 03 Apr 2005 14:46:29 +0000
Subject: Re: __autoload() enhancement
References: 1 2  Groups: php.internals 
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Alan, Your blog entry is actually what made me look into that topic. I'm not sure whether I agree with you regarding the general necessity of __autoload(). __autoload() is not only about saving the headache of explicit require()'s, it's also about 'JITing' this task, so that no classes are loaded unless you actually use them. The main things I took from there are that __autoload() is broken since it's limited to just one declaration, and that somehow an alternative was introduced into SPL, which is slightly scary. Zeev At 15:58 03/04/2005, Alan Knowles wrote:
I dont know if you read the blog comments here: http://www.akbkhome.com/blog.php/View/79/require_once+is+part+of+your +documentation..html and here http://www.akbkhome.com/blog.php/View/77/is+__autoload+evil%3F.html and slightly related http://www.akbkhome.com/blog.php/View/76/require_once%2C+one +optimization+too+many%3F.html It's pretty clear that people want to use autoload to save them having to deal with include paths.. (and perhaps save a few stat calls) - the more straightforward solution would be to add a include/require callback handler - so that rather than a class instantation action, magically doing file operations, you had a simpler and more obvious way to manage inclusions. But I guess Until I bother hacking something up for it, it'll remain little more than another heckle from the audience. ;) Regards Alan On Sun, 2005-04-03 at 13:05 +0300, Zeev Suraski wrote: All, One problem that became apparent after the introduction of __autoload(), is that different pieces of code, sometimes coming from different sources, may want to declare this function in a different way. Today, __autoload() is treated like any other function, so it's impossible to re-declare it. Marcus tried to solve it by introducing an __autoload() wrapper in SPL. Personally I think it's probably not the right way to go, but that's beside the point right now. What I'd like to suggest is a change in the behavior of __autoload(), so that multiple __autoload()'s could be defined. Essentially, declaring __autoload() would in fact add the function to the list of functions that are called in case a missing class is referenced. However, it will not actually place a function named __autoload() in the PHP function table. That way, it would be possible to declare multiple __autoloads(), and have all of them called when a missing class is spotted. The two issues with this solution are: 1. It will be impossible to use the standard means to determine whether __autoload() is declared or not. I don't think that's a very important issue but it's there nonetheless. 2. We need to determine what makes sense as far as calling order if we have more than one __autoload(). My guess would be calling them in the order they were registered, and checking whether the class was defined after each one (if it was - stop). That solution maintains downwards compatibility (almost, other than issue #1). Thoughts? Zeev


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