灵活的__autoload计划 [英] Flexible __autoload scheme
问题描述
随着PHP5的出现，以及它的OO支持和新的__autoload
功能，我正在考虑实施一些计划之王来组织这样一个
类。它们可以通过__autoload
函数轻松找到，但同时也可以清楚地组织课程。
目前（在PHP4中）我'使用类似Java的方案，借用ActiveLink
IORCA（ www.active-link.com），它使用特殊的import（）函数和
类在文件和目录中组织。每次我需要某个
类时，我必须手动导入相应的类或包。这很好，直观地特别适合那些有Java经验的人，但是作为
PHP5为我们提供了一个很好的功能，如__autoload函数，我会很多
更喜欢利用它。
对于那些不知道的人来说，__ autoload是一个神奇的功能，叫做
每个时间一个先前未定义的类，被调用的类名称作为参数传递给
。 Andi和Zeev在他们即将出版的书中（参见
http ：//www.zend.com/php5/andi-book-excerpt.php ）给出最简单的例子：
函数__autoload（$ class_name）{
include_once（$ class_name。" php"）;
}
但是，这会导致单个类文件混乱目录，和
整个系统需要更多的组织。首先，我将
至少将上述代码更改为：
define（''AUTOLOAD_CLASS_DIR''，''/ classes /''） ;
函数__autoload（$ class_name）{
require_once（AUTOLOAD_CLASS_DIR。$ class_name。" .class.php"）;
}
这会给我一个中心类目录，其中存储我所有的类
，以及一个不同的扩展名（class.php）对于类文件;
现在还需要类文件而不是包含。但是，它仍然有点简陋：如果我想按项目组织我的课程，
包等怎么办？
我正在考虑一个系统，其中所有的class.php文件都将在目录中组织
，__ autoload函数将以某种方式找到正确的
。
遍历所有目录可能会太慢，
，特别是在大型类层次结构中。一种方法是__autoload
包含一个定义数组的文件，该数组有效地镜像文件系统
结构。这意味着我们每次添加（或
移动）一个类时都需要编辑数组，或者实现一种机制，如果一个类
isn''发现，猛扑过目录并重新创建结构。
另一个缺点仍然存在，即每个类仍然需要
必须有一个不同的名称才能识别由系统。
这看起来似乎可能有用（我仍然需要写它），但是我很好b / b
好奇如果有人有一些不同最好更好地实现
这个。
Berislav
-
如果互联网是马克斯兄弟电影，网络，电子邮件和IRC是Groucho，Chico和Harpo，那么Usenet就是Zeppo。
With the advent of PHP5, with its OO support and the new __autoload
function, I was thinking of implementing some king of scheme to organize
classes in such a way that they can be easily found by the __autoload
function, yet at the same time would have clear organization of classes.
Currently (in PHP4) I''m using a Java-like scheme, borrowed from ActiveLink
IORCA (www.active-link.com), which uses a special import() function and
classes organized in files and directories. Each time I need a certain
class, I must manually import the appropriate class or package. This works
nicely, and intuitively especially for those with experience in Java, but as
PHP5 offers us such a nice feature as the __autoload function, I would much
prefer to take advantag of it.
For those who don''t know, __autoload is a magical function that is called
each time a previously undefined class, with the called class name passed as
the argument. Andi and Zeev in their upcoming book (see
http://www.zend.com/php5/andi-book-excerpt.php) give the simplest example:
function __autoload($class_name) {
include_once($class_name . "php");
}
However, this leads to a clutter of class files in a single directory, and
the whole system calls for a little more organization. First of all, I would
at least change the above code to:
define(''AUTOLOAD_CLASS_DIR'', ''/classes/'');
function __autoload($class_name) {
require_once(AUTOLOAD_CLASS_DIR . $class_name . ".class.php");
}
This would give me a single central classes directory where all my classes
are stored, as well as a distinct extension (class.php) for class files;
also the class file is now required instead of included. However, it is
still a bit spartan: what if I want to organize my classes by projects,
package etc?
I was thinking of a system where all the class.php files would be organized
in directories, and the __autoload function would somehow be able to find
the right one.
Going through all the directories would potentionally be too slow,
especially in a large classes hierarchy. One approach is that the __autoload
includes a file defining an array which effectively mirrors the filesystem
structure. This means that we need to edit the array each time we add (or
move) a class, or perhaps implementing a mechanism that would, if a class
isn''t found, swoop through the directories and recreate the structure.
Another downside would still remain, which is that each class would still
have to have a different name to be recognized by the system.
This seems like it might work (I still have to write it, though), but I am
curious if anyone has some different and preferably better idea to implement
this.
Berislav
--
If the Internet is a Marx Brothers movie, and Web, e-mail, and IRC are
Groucho, Chico, and Harpo, then Usenet is Zeppo.
推荐答案
class_name）{
include_once（
class_name) {
include_once(
class_name。" php"）;
}
然而，这会导致混乱在单个目录中的类文件，以及整个系统需要更多组织的
。首先，我将
至少将上述代码更改为：
define（''AUTOLOAD_CLASS_DIR''，''/ classes /''） ;
函数__autoload（
class_name . "php");
}
However, this leads to a clutter of class files in a single directory, and
the whole system calls for a little more organization. First of all, I would
at least change the above code to:
define(''AUTOLOAD_CLASS_DIR'', ''/classes/'');
function __autoload(
class_name）{
require_once（AUTOLOAD_CLASS_DIR。
class_name) {
require_once(AUTOLOAD_CLASS_DIR .
这篇关于灵活的__autoload计划的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
