本博客要講的是yii整個(gè)Application的創(chuàng)建過(guò)程，而不是運(yùn)行過(guò)程哈，讀者注意，沒(méi)有run啊。 閱讀前須知： web的Application ? ? ? ? ?extends ?yiibaseApplication yiibaseApplication ? ? ?extends ?yiibasemodule yiibasemodule ? ? ? ? ? ?extends ?yiibaseservicelocator yiibaseservicelocator ?extends ?yiibasecomponent yiibasecomponent ? ? ?extends ?yiibasepbject 其中我最關(guān)心的 __get ?__set函數(shù)是在component類(lèi)中定義的
1.$config該變量是我們從配置文件加載出來(lái)的，一個(gè)配置數(shù)組的合集（其中的各種require文件就不說(shuō)了?。?2.Application的創(chuàng)建過(guò)程

public?function?__construct($config?=?[])
{

????Yii::$app?=?$this;
????static::setInstance($this);
????$this->state?=?self::STATE_BEGIN;
????$this->preInit($config);
????$this->registerErrorHandler($config);
????Component::__construct($config);
}

解讀setInstance，函數(shù)定義如下：

public?static?function?setInstance($instance)
{
????if?($instance?===?null)?{
????????unset(Yii::$app->loadedModules[get_called_class()]);
????}?else?{
????????Yii::$app->loadedModules[get_class($instance)]?=?$instance;
????}
}

現(xiàn)在的loadedModules，我還沒(méi)有具體看不知道啥意思，不過(guò)對(duì)于我這種小白來(lái)說(shuō)，可以暫時(shí)忽略 解讀preInit($config)

public?function?preInit(&$config)
{
????if?(!isset($config['id']))?{
????????throw?new?InvalidConfigException('The?"id"?configuration?for?the?Application?is?required.');
????}
????if?(isset($config['basePath']))?{
????????$this->setBasePath($config['basePath']);
????????unset($config['basePath']);
????}?else?{
????????throw?new?InvalidConfigException('The?"basePath"?configuration?for?the?Application?is?required.');
????}

????if?(isset($config['vendorPath']))?{
????????$this->setVendorPath($config['vendorPath']);
????????unset($config['vendorPath']);
????}?else?{
????????//?set?"@vendor"
????????$this->getVendorPath();
????}
????if?(isset($config['runtimePath']))?{
????????$this->setRuntimePath($config['runtimePath']);
????????unset($config['runtimePath']);
????}?else?{
????????//?set?"@runtime"
????????$this->getRuntimePath();
????}

????if?(isset($config['timeZone']))?{
????????$this->setTimeZone($config['timeZone']);
????????unset($config['timeZone']);
????}?elseif?(!ini_get('date.timezone'))?{
????????$this->setTimeZone('UTC');
????}
????//以上除了id，意外，配置文件必須包含?basePath,vendorPath??runtimePath等變量，并將變量放在module類(lèi)中對(duì)應(yīng)的成員變量中

????//并且設(shè)置完成之后進(jìn)行unset操作

????//?merge?core?components?with?custom?components
????foreach?($this->coreComponents()?as?$id?=>?$component)?{
????????if?(!isset($config['components'][$id]))?{
????????????$config['components'][$id]?=?$component;
????????}?elseif?(is_array($config['components'][$id])?&&?!isset($config['components'][$id]['class']))?{
????????????$config['components'][$id]['class']?=?$component['class'];
????????}
????}
}

需要注意的就是這個(gè)coreComponent函數(shù)了，這個(gè)函數(shù)，將web的Application和base的Application的coreComponents返回的數(shù)組進(jìn)行合并操作，也就是說(shuō)在 整個(gè)應(yīng)用中需要用到的components都需要在webApplication的coreComponents或者其父類(lèi)的coreComponents中進(jìn)行定義，并且組件的定義優(yōu)先取用配置文件中的定義 PS:以上這幾步，我們可以認(rèn)為是進(jìn)行預(yù)整理$config 接下來(lái)是registerErrorHandler,這個(gè)函數(shù)以后會(huì)著重看，先按下不表。 看一下Component::__construct的定義，他最終調(diào)用的是Yii::Configure

public?static?function?configure($object,?$properties)
{
????foreach?($properties?as?$name?=>?$value)?{

????????$object->$name?=?$value;
????}
????return?$object;
}

接下來(lái)，要說(shuō)的就是這個(gè) ->$name = $value;我們知道這個(gè)$object是web下的Application，該類(lèi)有一個(gè)父類(lèi)是Component，不知道的可以去看，閱讀前須知 該類(lèi)中定義了注入函數(shù)__set

public?function?__set($name,?$value)
{
????$setter?=?'set'?.?$name;
????if?(method_exists($this,?$setter))?{
????????//?set?property
????????$this->$setter($value);
????????return;
????}?elseif?(strncmp($name,?'on?',?3)?===?0)?{
????????//?on?event:?attach?event?handler
????????$this->on(trim(substr($name,?3)),?$value);
????????return;
????}?elseif?(strncmp($name,?'as?',?3)?===?0)?{
????????//?as?behavior:?attach?behavior
????????$name?=?trim(substr($name,?3));
????????$this->attachBehavior($name,?$value?instanceof?Behavior???$value?:?Yii::createObject($value));
????????return;
????}?else?{
????????//?behavior?property
????????$this->ensureBehaviors();
????????foreach?($this->_behaviors?as?$behavior)?{
????????????if?($behavior->canSetProperty($name))?{
????????????????$behavior->$name?=?$value;
????????????????return;
????????????}
????????}
????}
????if?(method_exists($this,?'get'?.?$name))?{
????????throw?new?InvalidCallException('Setting?read-only?property:?'?.?get_class($this)?.?'::'?.?$name);
????}?else?{
????????throw?new?UnknownPropertyException('Setting?unknown?property:?'?.?get_class($this)?.?'::'?.?$name);
????}
}

對(duì)于需要組件的會(huì)有單獨(dú)的處理函數(shù)（set.$name函數(shù)），我們?cè)谂渲梦募袝?huì)定義諸如

return?[
????'components'?=>?[
????????'db'?=>?[
????????????'class'?=>?'yiidbConnection',
????????????'dsn'?=>?'mysql:host=db1-dev.bj1.haodf.net;dbname=test',
????????????'username'?=>?'weihu_dev',
????????????'password'?=>?'hdf@haodf.com',
????????????'charset'?=>?'gbk',
????????],
????????'mailer'?=>?[
????????????'class'?=>?'yiiswiftmailerMailer',
????????????'viewPath'?=>?'@common/mail',
????????????//?send?all?mails?to?a?file?by?default.?You?have?to?set
????????????//?'useFileTransport'?to?false?and?configure?a?transport
????????????//?for?the?mailer?to?send?real?emails.
????????????'useFileTransport'?=>?true,
????????],
????],
];

但是在ServiceLocator中定義了也就是對(duì)于配置文件中的components，定義了setComponents函數(shù)進(jìn)行處理

public?function?setComponents($components)
{
????foreach?($components?as?$id?=>?$component)?{
????????$this->set($id,?$component);
????}
}

繼續(xù)分析

public?function?set($id,?$definition)
{
????if?($definition?===?null)?{
????????unset($this->_components[$id],?$this->_definitions[$id]);
????????return;
????}

????unset($this->_components[$id]);

????if?(is_object($definition)?||?is_callable($definition,?true))?{
????????//?an?object,?a?class?name,?or?a?PHP?callable
????????$this->_definitions[$id]?=?$definition;
????}?elseif?(is_array($definition))?{
????????//?a?configuration?array
????????if?(isset($definition['class']))?{
????????????$this->_definitions[$id]?=?$definition;
????????}?else?{
????????????throw?new?InvalidConfigException("The?configuration?for?the?"$id"?component?must?contain?a?"class"?element.");
????????}
????}?else?{
????????throw?new?InvalidConfigException("Unexpected?configuration?type?for?the?"$id"?component:?"?.?gettype($definition));
????}
}

這樣所有Components就會(huì)有單獨(dú)的_components數(shù)組進(jìn)行統(tǒng)一維護(hù)了?。。。。ū热鏳b，比如cache就是在這里進(jìn)行組成的） 還需要說(shuō)明的就是除了components意外的其他配置，


可以在配置文件中添加整個(gè)應(yīng)用的事件或者行為而不是單獨(dú)針對(duì)某個(gè)controller的了，其配置如下：

$config['on?test']=['class'=>'test'];