Symfoy2 source code analysis - startup process 1, symfoy2 source code

This article reads and analyzes the source code of Symfony2 to understand what work is done in the startup process of Symfony2, and understand the Symfony2 framework from reading the source code.

The core essence of Symfony2 is the process of converting Request into Response.

Let’s take a look at the source code of the entry file (web_dev.php). The entry file generally describes the working process of the Symfony2 framework:

<span> 1</span> require_once __DIR__.<span>'</span><span>/../app/AppKernel.php</span><span>'</span><span>;
</span><span> 2</span> 
<span> 3</span> $kernel = <span>new</span> AppKernel(<span>'</span><span>dev</span><span>'</span>, <span>true</span><span>);
</span><span> 4</span> $kernel-><span>loadClassCache();
</span><span> 5</span> <span>//</span><span>利用请求信息（$_GET $_POST $_SERVER等等）构造Request对象</span>
<span> 6</span> $request =<span> Request::createFromGlobals();
</span><span> 7</span> <span>//</span><span>Symfony2框架核心工作就是把Request对象转换成Response对象</span>
<span> 8</span> $response = $kernel-><span>handle($request);
</span><span> 9</span> <span>//</span><span>向客户端输出Response对象</span>
<span>10</span> $response-><span>send();
</span><span>11</span> <span>//</span><span>完成一些耗时的后台操作，例如邮件发送，图片裁剪等等耗时工作</span>
<span>12</span> $kernel->terminate($request, $response);

Copy after login

The Symfony2 framework determines the data to generate and return the response through the client's request information. The focus of our Symfony2 source code analysis below is the AppKernel::handle method.

The implementation of AppKernel::handle is inherited from Kernel::handle

<span> 1</span>     <span>/*</span><span>*
</span><span> 2</span> <span>     *
</span><span> 3</span> <span>     * @param Request $request Request对象实例
</span><span> 4</span> <span>     * @param int     $type    请求的类型（子请求 or 主请求）
</span><span> 5</span> <span>     * @param bool    $catch   是否捕捉异常
</span><span> 6</span> <span>     *
</span><span> 7</span> <span>     * @return Response Response对象实例
</span><span> 8</span> <span>     *
</span><span> 9</span>      <span>*/</span>    
<span>10</span>     <span>public</span> function handle(Request $request, $type = HttpKernelInterface::MASTER_REQUEST, $<span>catch</span> = <span>true</span><span>)
</span><span>11</span> <span>    {   
</span><span>12</span>         <span>//</span><span>$this->booted Symfony2框架只启动一次</span>
<span>13</span>         <span>if</span> (<span>false</span> === $<span>this</span>-><span>booted) {
</span><span>14</span>             <span>//</span><span>初始化并启动所有注册在AppKernel里面的所有bundles（AppKernel::registerBundles）
</span><span>15</span>             <span>//</span><span>初始化container
</span><span>16</span>             <span>//</span><span>加载、缓存配置数据和路由数据、编译container容器等，为后面事件处理做准备。</span>
<span>17</span>             $<span>this</span>-><span>boot();
</span><span>18</span> <span>        }
</span><span>19</span> 
<span>20</span>         <span>//</span><span>开启事件处理，Symfony2内核的请求处理过程本质是一系列的事件处理过程</span>
<span>21</span>         <span>return</span> $<span>this</span>->getHttpKernel()->handle($request, $type, $<span>catch</span><span>);
</span><span>22</span>     }

Copy after login

AppKernel::boot method

<span> 1</span>     <span>public</span><span> function boot()
</span><span> 2</span> <span>    {
</span><span> 3</span>         <span>if</span> (<span>true</span> === $<span>this</span>-><span>booted) {
</span><span> 4</span>             <span>return</span><span>;
</span><span> 5</span> <span>        }
</span><span> 6</span> 
<span> 7</span>         <span>if</span> ($<span>this</span>-><span>loadClassCache) {
</span><span> 8</span>             $<span>this</span>->doLoadClassCache($<span>this</span>->loadClassCache[<span>0</span>], $<span>this</span>->loadClassCache[<span>1</span><span>]);
</span><span> 9</span> <span>        }
</span><span>10</span> 
<span>11</span>         <span>//</span><span> init bundles
</span><span>12</span>         <span>//</span><span>初始化注册到AppKernel里的所有bundle（AppKernel::registerBundles）</span>
<span>13</span>         $<span>this</span>-><span>initializeBundles();
</span><span>14</span> 
<span>15</span>         <span>//</span><span> init container
</span><span>16</span>         <span>//</span><span>初始化并编译缓存container，包括载入配置信息、编译信息、service等
</span><span>17</span>         <span>//</span><span>Symfony2的核心组件的加载，和各个组件之间的关联关系都在container容器初始化中完成，所以这会是下面详细描述</span>
<span>18</span>         $<span>this</span>-><span>initializeContainer();
</span><span>19</span> 
<span>20</span>         <span>//</span><span>把bundle注入到container，并启动bundle</span>
<span>21</span>         <span>foreach</span> ($<span>this</span>->getBundles() <span>as</span><span> $bundle) {
</span><span>22</span>             $bundle->setContainer($<span>this</span>-><span>container);
</span><span>23</span>             $bundle-><span>boot();
</span><span>24</span> <span>        }
</span><span>25</span> 
<span>26</span>         <span>//</span><span>标记Symfony2只启动一次并启动成功</span>
<span>27</span>         $<span>this</span>->booted = <span>true</span><span>;
</span><span>28</span>     }

Copy after login

AppKernel::initializeContainer source code analysis

<span> 1</span>     <span>protected</span><span> function initializeContainer()
</span><span> 2</span> <span>    {
</span><span> 3</span>         <span>//</span><span>检查app/cache/dev[prod]缓存文件是否过期，以container缓存文件的最后修改时间为参考时间，
</span><span> 4</span>         <span>//</span><span>如果app/cache/dev[prod]下的存在一个或者多个缓存文件的最后修改时间大于container缓存文件的
</span><span> 5</span>         <span>//</span><span>最后修改时间，就判断为缓存过期。
</span><span> 6</span>         <span>//</span><span>另外，如果$this->debug为false（即关闭debug的情况下）只要container缓存文件存在，那么就认为
</span><span> 7</span>         <span>//</span><span>缓存不过期</span>
<span> 8</span>         $<span>class</span> = $<span>this</span>-><span>getContainerClass();
</span><span> 9</span>         $cache = <span>new</span> ConfigCache($<span>this</span>->getCacheDir().<span>'</span><span>/</span><span>'</span>.$<span>class</span>.<span>'</span><span>.php</span><span>'</span>, $<span>this</span>-><span>debug);
</span><span>10</span>         $fresh = <span>true</span><span>;
</span><span>11</span>         <span>if</span> (!$cache-><span>isFresh()) {
</span><span>12</span>             <span>//</span><span>初始化一个ContainerBuilder对象实例；
</span><span>13</span>             <span>//</span><span>自动加载所有注册的Bundle的DependencyInjection下的所有extension，Bundle可以通过extension来加载属于该Bundle配置（service的配置、
</span><span>14</span>             <span>//</span><span>路由的配置等等）、Bundle的全局变量等
</span><span>15</span>             <span>//</span><span>同时这些extension加载的信息都会被保存到container中；
</span><span>16</span>             <span>//</span><span>加载并保存compiler pass到container，为下一步compile做准备，我们可以通过compiler pass修改已经注册到container的service的属性
</span><span>17</span>             <span>//</span><span>compiler pass的官方文档http:</span><span>//</span><span>symfony.com/doc/current/cookbook/service_container/compiler_passes.html</span>
<span>18</span>             $container = $<span>this</span>-><span>buildContainer();
</span><span>19</span>             <span>//</span><span>执行compiler pass 的process方法，container的compile过程主要是执行上一步保存到container内的compiler pass 的process方法</span>
<span>20</span>             $container-><span>compile();
</span><span>21</span>             <span>//</span><span>生成container的缓存（appDevDebugProjectContainer.php），该container包含了service的获取方法、别名的映射关系</span>
<span>22</span>             $<span>this</span>->dumpContainer($cache, $container, $<span>class</span>, $<span>this</span>-><span>getContainerBaseClass());
</span><span>23</span> 
<span>24</span>             $fresh = <span>false</span><span>;
</span><span>25</span> <span>        }
</span><span>26</span> 
<span>27</span>         
<span>28</span> <span>        require_once $cache;
</span><span>29</span> 
<span>30</span>         $<span>this</span>->container = <span>new</span> $<span>class</span><span>();
</span><span>31</span>         $<span>this</span>->container-><span>set</span>(<span>'</span><span>kernel</span><span>'</span>, $<span>this</span><span>);
</span><span>32</span> 
<span>33</span>         <span>//</span><span>...............</span>
<span>34</span>         <span>if</span> (!$fresh && $<span>this</span>->container->has(<span>'</span><span>cache_warmer</span><span>'</span><span>)) {
</span><span>35</span>             $<span>this</span>->container-><span>get</span>(<span>'</span><span>cache_warmer</span><span>'</span>)->warmUp($<span>this</span>->container->getParameter(<span>'</span><span>kernel.cache_dir</span><span>'</span><span>));
</span><span>36</span> <span>        }
</span><span>37</span>     }

Copy after login

<span> 1</span>     <span>protected</span><span> function prepareContainer(ContainerBuilder $container)
</span><span> 2</span> <span>    {
</span><span> 3</span>         $extensions =<span> array();
</span><span> 4</span>         <span>foreach</span> ($<span>this</span>->bundles <span>as</span><span> $bundle) {
</span><span> 5</span>             <span>//</span><span>加载DependencyInjection下的Extension，所有Extension必需实现Extension接口</span>
<span> 6</span>             <span>if</span> ($extension = $bundle-><span>getContainerExtension()) {
</span><span> 7</span>                 $container-><span>registerExtension($extension);
</span><span> 8</span>                 $extensions[] = $extension-><span>getAlias();
</span><span> 9</span> <span>            }
</span><span>10</span> 
<span>11</span>             <span>//</span><span>开启debug的情况下，把bundles添加到recourses</span>
<span>12</span>             <span>if</span> ($<span>this</span>-><span>debug) {
</span><span>13</span>                 $container-><span>addObjectResource($bundle);
</span><span>14</span> <span>            }
</span><span>15</span> <span>        }
</span><span>16</span>         <span>foreach</span> ($<span>this</span>->bundles <span>as</span><span> $bundle) {
</span><span>17</span>             <span>//</span><span>通常用来添加compiler pass</span>
<span>18</span>             $bundle-><span>build($container);
</span><span>19</span> <span>        }
</span><span>20</span> 
<span>21</span>         <span>//</span><span> ensure these extensions are implicitly loaded</span>
<span>22</span>         $container->getCompilerPassConfig()->setMergePass(<span>new</span><span> MergeExtensionConfigurationPass($extensions));
</span><span>23</span>     }

Copy after login

From AppKernel::initializeContainer, we can see that Bundle and container are the basic core of the Symfony2 framework. Container is the unified management center for all components of the Symfony2 framework. Bundle is an organization of functional modules.

If you are curious about how the service and configuration parameters are loaded, you can learn more about Symfony2's Extension; if you are curious about how to further improve and modify the loaded service, you can learn more about Symfony2's compiler pass.

At this step, the Symfony2 framework startup is almost complete, and we are ready for the subsequent kernel event processing EventDispatcher::dispatch.

The next article explains the kernel event processing of the Symfony2 framework.

How to write a source code in Yi language so that the attribute transformation of the startup window, such as skin change, can be controlled by controlling the buttons in window 1,

This is to use the button click event to change the skin. If it is placed under the startup window, the skin will appear different every time you open it.

Symfoy2 source code analysis - startup process 1, symfoy2 source code_PHP tutorial

Who can give me an Easy Language source code on how to make the software I compiled start randomly?

Just use the following code, it’s very simple,

Write the registration item (3, "software\microsoft\windows\CurrentVersion\Run\My Startup Item", "The directory where your program is located + file name")