图书馆作为Singleton在Codeigniter? [英] Library as Singleton in Codeigniter?
问题描述
我已经使用单例模式创建了一个自定义库。为什么要这样呢?因为我需要能够调用我的函数而不用 $ this - > 引用,例如,我可以执行下面的代码:
function foo(){
MyLibrary :: instance() - > foo()
}
那么我可以像这样在控制器中调用我的函数:
function foo();
的实例
$ this-> mylibrary-> foo();
我有麻烦,因为CodeIgniter尝试instanciate我的库,当最好的方法是读静态实例。
为什么我需要这样做?
我的自定义库必须从外部php文件注册hooks in / plugins目录外部的应用程序文件夹。看:
- / application
- / plugins
- /plugins/helloworld.php
这是我的Loader程式库:
class Loader {
public static $ instance;
protected $ hooks;
私有函数__construct($ params = array()){
$ this-> hooks = array();
$ this-> includePlugins();
}
public static function instance()
{
if(!self :: $ instance)
{
self :: $ instance = new Loader();
}
return self :: $ instance;
}
public function includePlugins()
{
include_once/plugins/helloworld.php;
}
public function do_action($ hook =after)
{
foreach($ this-> actions [$ hook] as $ function)
{
call_user_func_array($ function,array());
}
}
public function add_action($ hook,$ function,$ priority)
{
if($ hooks! = false)
{
$ this-> actions [$ hook] [] = $ function;
}
else
{
echo钩名称不可用;
}
}
}
/ **
*使用Singleton实例的函数! !
* /
function do_action($ hook)
{
Loader :: instance() - > do_action
}
function add_action($ hook,$ function,$ priority)
{
Loader :: instance() - > add_action ,$ priority);
}
否,my helloworld.php(plugin)看起来像这样:
add_action('right_here','show_message',11)
function show_message()
{
echohello world!;
}
最后,我可以在我的控制器/视图中调用我的函数do_action以打印此消息,如下所示:
do_action('right_here');注意,我所有的重要函数都是通过一个全局函数来调用的,它允许我使用单例实例。但我遇到两个问题:
- Codeigniter需要我的结果公开为了
instanciate。
- 如果我将其公开,则会创建多个实例,并且库
将无法按预期工作。
解决方案我已解决问题:)
要创建单例库,您必须:
-
在system / core / Codeigniter.php中包含您的库如下:
require_once(/ path / to / library.php);
-
使用& ,如下所示:
单身:
public static function& instance()
{
if(!self :: $ instance)
{
self :: $ instance = new Loader ();
}
return self :: $ instance;
}
- 准备使用您的功能。此外,您可以在库中加入CI
对象。
I've created a custom library using singleton pattern. Why by this way? because I need to be able to call my functions without $this-> reference, for example, I could execute the code below:
function foo() {
MyLibrary::instance()->foo();
}
then I could call my functions in controllers like this:
function foo();
instance of
$this->mylibrary->foo();
I am in trouble because CodeIgniter try to instanciate my library when the best way to do is "read" the static instance.
Why I need to do this?
My custom library must register "hooks" from external php files located in /plugins directory outsite of application folder. Look:
- /application
- /plugins
- /plugins/helloworld.php
This is my Loader library:
class Loader{
public static $instance;
protected $hooks;
private function __construct($params = array()){
$this->hooks= array();
$this->includePlugins();
}
public static function instance()
{
if (!self::$instance)
{
self::$instance = new Loader();
}
return self::$instance;
}
public function includePlugins()
{
include_once "/plugins/helloworld.php";
}
public function do_action($hook= "after")
{
foreach ($this->actions[$hook] as $function)
{
call_user_func_array($function, array());
}
}
public function add_action($hook, $function, $priority)
{
if ($hooks !== false)
{
$this->actions[$hook][] = $function;
}
else
{
echo "hook name is unavaliable";
}
}
}
/**
* Functions using the Singleton instance !!!
*/
function do_action($hook)
{
Loader::instance()->do_action($hook);
}
function add_action($hook, $function, $priority)
{
Loader::instance()->add_action($hook, $function, $priority);
}
No, my helloworld.php (plugin) looks like this:
add_action('right_here', 'show_message', 11);
function show_message()
{
echo "hello world!";
}
Finally, I could call my the function do_action in my controller/view in order to print the message, like this:
do_action('right_here');
Note that all my important functions are called by a global function that allow me to use the singleton instance. But I am experiencing two issues:
- Codeigniter needs that my contruct be public in order to
instanciate. Here I need to take my singleton.
- If I let it public, several instances will be created and the library
will no longer works as expected.
解决方案 I've solved the problem :)
In order to create a singleton library you must:
Include your library at system/core/Codeigniter.php like this:
require_once("/path/to/library.php");
Make your instance return with & symbol, like this:
Singleton:
public static function &instance()
{
if (!self::$instance)
{
self::$instance = new Loader();
}
return self::$instance;
}
- Ready to uses your functions as well. Also, you can include th CI
object in you library.
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