在官方文件：Views & Responses裡呼叫Redirect類別靜態函式，背後是在呼叫這支Redirector.php類別的實體。
主要功能是由UrlGenerator類別產生URL、再丟給RedirectResponse類別產生轉址的HTTP header。
此外Redirector還提供某些需要紀錄當前URL、上一個URL相關的轉址功能，所以還需要Session的協助。

此處提到的許多函式，官網都沒有寫出來喔！

generator = $generator;
	}

	/**
	 * Create a new redirect response to the "home" route.
	 *
	 * @param  int  $status
	 * @return \Illuminate\Http\RedirectResponse
	 */
	public function home($status = 302)
	{
		return $this->to($this->generator->route('home'), $status);
	}

如果有設定名為’home’的Named Route，這個函式可以直接轉往它。
所以Laravel其實鼓勵你的routes中設一個名為home的首頁呢。

	/**
	 * Create a new redirect response to the previous location.
	 *
	 * @param  int    $status
	 * @param  array  $headers
	 * @return \Illuminate\Http\RedirectResponse
	 */
	public function back($status = 302, $headers = array())
	{
		$back = $this->generator->getRequest()->headers->get('referer');

		return $this->createRedirect($back, $status, $headers);
	}

從HTTP HEADER的REFERER找到前一個網址，然後轉過去。

	/**
	 * Create a new redirect response to the current URI.
	 *
	 * @param  int    $status
	 * @param  array  $headers
	 * @return \Illuminate\Http\RedirectResponse
	 */
	public function refresh($status = 302, $headers = array())
	{
		return $this->to($this->generator->getRequest()->path(), $status, $headers);
	}

轉往原網址。

咦？？？什麼情況會需要原地轉址？？？

	/**
	 * Create a new redirect response, while putting the current URL in the session.
	 *
	 * @param  string  $path
	 * @param  int     $status
	 * @param  array   $headers
	 * @param  bool    $secure
	 * @return \Illuminate\Http\RedirectResponse
	 */
	public function guest($path, $status = 302, $headers = array(), $secure = null)
	{
		$this->session->put('url.intended', $this->generator->full());

		return $this->to($path, $status, $headers, $secure);
	}

轉址的同時記下當前的URL。

	/**
	 * Create a new redirect response to the previously intended location.
	 *
	 * @param  string  $default
	 * @param  int     $status
	 * @param  array   $headers
	 * @param  bool    $secure
	 * @return \Illuminate\Http\RedirectResponse
	 */
	public function intended($default = '/', $status = 302, $headers = array(), $secure = null)
	{
		$path = $this->session->pull('url.intended', $default);

		return $this->to($path, $status, $headers, $secure);
	}

轉往上一次guest函式執行時記下的URL。

	/**
	 * Create a new redirect response to the given path.
	 *
	 * @param  string  $path
	 * @param  int     $status
	 * @param  array   $headers
	 * @param  bool    $secure
	 * @return \Illuminate\Http\RedirectResponse
	 */
	public function to($path, $status = 302, $headers = array(), $secure = null)
	{
		$path = $this->generator->to($path, array(), $secure);

		return $this->createRedirect($path, $status, $headers);
	}

轉往指定URL。
能接受$secure參數，判斷是否為HTTPS協定，修改URL之後才轉。

	/**
	 * Create a new redirect response to an external URL (no validation).
	 *
	 * @param  string  $path
	 * @param  int     $status
	 * @param  array   $headers
	 * @return \Illuminate\Http\RedirectResponse
	 */
	public function away($path, $status = 302, $headers = array())
	{
		return $this->createRedirect($path, $status, $headers);
	}

轉往外部網址。

其實to函式也可以轉往外部網址，這個away函式目前沒有意義。
應該是放在這邊，提醒之後要實作此功能吧。

	/**
	 * Create a new redirect response to the given HTTPS path.
	 *
	 * @param  string  $path
	 * @param  int     $status
	 * @param  array   $headers
	 * @return \Illuminate\Http\RedirectResponse
	 */
	public function secure($path, $status = 302, $headers = array())
	{
		return $this->to($path, $status, $headers, true);
	}

轉往某HTTPS協定的網址。

意義不大，使用to函式並將第四個參數設為true即可。

	/**
	 * Create a new redirect response to a named route.
	 *
	 * @param  string  $route
	 * @param  array   $parameters
	 * @param  int     $status
	 * @param  array   $headers
	 * @return \Illuminate\Http\RedirectResponse
	 */
	public function route($route, $parameters = array(), $status = 302, $headers = array())
	{
		$path = $this->generator->route($route, $parameters);

		return $this->to($path, $status, $headers);
	}

routes如果有命名的話，可以用此函式轉往特定name。

	/**
	 * Create a new redirect response to a controller action.
	 *
	 * @param  string  $action
	 * @param  array   $parameters
	 * @param  int     $status
	 * @param  array   $headers
	 * @return \Illuminate\Http\RedirectResponse
	 */
	public function action($action, $parameters = array(), $status = 302, $headers = array())
	{
		$path = $this->generator->action($action, $parameters);

		return $this->to($path, $status, $headers);
	}

轉往某個controller action。就是類似’UserController@showProfile’的東西。

	/**
	 * Create a new redirect response.
	 *
	 * @param  string  $path
	 * @param  int     $status
	 * @param  array   $headers
	 * @return \Illuminate\Http\RedirectResponse
	 */
	protected function createRedirect($path, $status, $headers)
	{
		$redirect = new RedirectResponse($path, $status, $headers);

		if (isset($this->session))
		{
			$redirect->setSession($this->session);
		}

		$redirect->setRequest($this->generator->getRequest());

		return $redirect;
	}

	/**
	 * Get the URL generator instance.
	 *
	 * @return  \Illuminate\Routing\UrlGenerator
	 */
	public function getUrlGenerator()
	{
		return $this->generator;
	}

	/**
	 * Set the active session store.
	 *
	 * @param  \Illuminate\Session\Store  $session
	 * @return void
	 */
	public function setSession(SessionStore $session)
	{
		$this->session = $session;
	}

}