<?php
/**
 * TRadioButton class file
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link http://www.pradosoft.com/
 * @copyright Copyright &copy; 2005-2011 PradoSoft
 * @license http://www.pradosoft.com/license/
 * @version $Id$
 * @package System.Web.UI.WebControls
 */

/**
 * Using TCheckBox parent class
 */
Prado::using('System.Web.UI.WebControls.TCheckBox');
/**
 * Using TRadioButtonList class
 */
Prado::using('System.Web.UI.WebControls.TRadioButtonList');

/**
 * TRadioButton class
 *
 * TRadioButton displays a radio button on the page.
 * You can specify the caption to display beside the radio buttonby setting
 * the {@link setText Text} property.  The caption can appear either on the right
 * or left of the radio button, which is determined by the {@link setTextAlign TextAlign}
 * property.
 *
 * To determine whether the TRadioButton component is checked, test the {@link getChecked Checked}
 * property. The {@link onCheckedChanged OnCheckedChanged} event is raised when
 * the {@link getChecked Checked} state of the TRadioButton component changes
 * between posts to the server. You can provide an event handler for
 * the {@link onCheckedChanged OnCheckedChanged} event to  to programmatically
 * control the actions performed when the state of the TRadioButton component changes
 * between posts to the server.
 *
 * TRadioButton uses {@link setGroupName GroupName} to group together a set of radio buttons.
 * Once the {@link setGroupName GroupName} is set, you can use the {@link getRadioButtonsInGroup}
 * method to get an array of TRadioButtons having the same group name.
 *
 * If {@link setAutoPostBack AutoPostBack} is set true, changing the radio button state
 * will cause postback action. And if {@link setCausesValidation CausesValidation}
 * is true, validation will also be processed, which can be further restricted within
 * a {@link setValidationGroup ValidationGroup}.
 *
 * Note, {@link setText Text} is rendered as is. Make sure it does not contain unwanted characters
 * that may bring security vulnerabilities.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @version $Id$
 * @package System.Web.UI.WebControls
 * @since 3.0
 */
class TRadioButton extends TCheckBox
{
	/**
	 * @param array list of radio buttons that are on the current page hierarchy
	 */
	private static $_activeButtons=array();
	/**
	 * @var integer number of radio buttons created
	 */
	private static $_buttonCount=0;
	/**
	 * @var integer global ID of this radiobutton
	 */
	private $_globalID;
	/**
	 * @var string previous UniqueID (used to calculate UniqueGroup)
	 */
	private $_previousUniqueID=null;
	/**
	 * @var string the name used to fetch radiobutton post data
	 */
	private $_uniqueGroupName=null;

	/**
	 * Constructor.
	 * Registers the radiobutton in a global radiobutton collection.
	 * If overridden, the parent implementation must be invoked first.
	 */
	public function __construct()
	{
		parent::__construct();
		$this->_globalID = self::$_buttonCount++;
	}

	/**
	 * Registers the radio button groupings. If overriding onInit method,
	 * ensure to call parent implemenation.
	 * @param TEventParameter event parameter to be passed to the event handlers
	 */
	public function onInit($param)
	{
		parent::onInit($param);
		self::$_activeButtons[$this->_globalID]=$this;
	}

	/**
	 * Unregisters the radio button groupings. If overriding onInit method,
	 * ensure to call parent implemenation.
	 * @param TEventParameter event parameter to be passed to the event handlers
	 */
	public function onUnLoad($param)
	{
		unset(self::$_activeButtons[$this->_globalID]);
		parent::onUnLoad($param);
	}

	/**
	 * Loads user input data.
	 * This method is primarly used by framework developers.
	 * @param string the key that can be used to retrieve data from the input data collection
	 * @param array the input data collection
	 * @return boolean whether the data of the control has been changed
	 */
	public function loadPostData($key,$values)
	{
		$uniqueGroupName=$this->getUniqueGroupName();
		$value=isset($values[$uniqueGroupName])?$values[$uniqueGroupName]:null;
		if($value!==null && $value===$this->getValueAttribute())
		{
			if(!$this->getChecked())
			{
				$this->setChecked(true);
				return true;
			}
			else
				return false;
		}
		else if($this->getChecked())
			$this->setChecked(false);
		return false;
	}

	/**
	 * @return string the name of the group that the radio button belongs to. Defaults to empty.
	 */
	public function getGroupName()
	{
		return $this->getViewState('GroupName','');
	}

	/**
	 * Sets the name of the group that the radio button belongs to.
	 * The group is unique among the control's naming container.
	 * @param string the group name
	 * @see setUniqueGroupName
	 */
	public function setGroupName($value)
	{
		$this->setViewState('GroupName',$value,'');
		$this->_uniqueGroupName=null;
	}

	/**
	 * Add the group name as post data loader if group name is set.
	 */
	protected function addToPostDataLoader()
	{
		parent::addToPostDataLoader();
		$group = $this->getGroupName();
		if(!empty($group) || $this->getViewState('UniqueGroupName','') !== '')
			$this->getPage()->registerPostDataLoader($this->getUniqueGroupName());
	}
	/**
	 * @return string the name used to fetch radiobutton post data
	 */
	public function getUniqueGroupName()
	{
		if(($groupName=$this->getViewState('UniqueGroupName',''))!=='')
			return $groupName;
		else if(($uniqueID=$this->getUniqueID())!==$this->_previousUniqueID || $this->_uniqueGroupName===null)
		{
			$groupName=$this->getGroupName();
			$this->_previousUniqueID=$uniqueID;
			if($uniqueID!=='')
			{
				if(($pos=strrpos($uniqueID,TControl::ID_SEPARATOR))!==false)
				{
					if($groupName!=='')
						$groupName=substr($uniqueID,0,$pos+1).$groupName;
					else if($this->getNamingContainer() instanceof TRadioButtonList)
						$groupName=substr($uniqueID,0,$pos);
				}
				if($groupName==='')
					$groupName=$uniqueID;
			}
			$this->_uniqueGroupName=$groupName;
		}
		return $this->_uniqueGroupName;
	}

	/**
	 * Sets the unique group name that the radio button belongs to.
	 * A unique group is a radiobutton group unique among the whole page hierarchy,
	 * while the {@link setGroupName GroupName} specifies a group that is unique
	 * among the control's naming container only.
	 * For example, each cell of a {@link TDataGrid} is a naming container.
	 * If you specify {@link setGroupName GroupName} for a radiobutton in a cell,
	 * it groups together radiobutton within a cell, but not the other, even though
	 * they have the same {@link setGroupName GroupName}.
	 * On the contratry, if {@link setUniqueGroupName UniqueGroupName} is used instead,
	 * it will group all appropriate radio buttons on the whole page hierarchy.
	 * Note, when both {@link setUniqueGroupName UniqueGroupName} and
	 * {@link setGroupName GroupName}, the former takes precedence.
	 * @param string the group name
	 * @see setGroupName
	 */
	public function setUniqueGroupName($value)
	{
		$this->setViewState('UniqueGroupName',$value,'');
	}

	/**
	 * Gets an array of radiobuttons whose group name is the same as this radiobutton's.
	 * Note, only those radiobuttons that are on the current page hierarchy may be
	 * returned in the result.
	 * @return array list of TRadioButton with the same group
	 */
	public function getRadioButtonsInGroup()
	{
		$group = $this->getUniqueGroupName();
		$buttons = array();
		foreach(self::$_activeButtons as $control)
		{
			if($control->getUniqueGroupName() === $group)
				$buttons[] = $control;
		}
		return $buttons;
	}

	/**
	 * @return string the value attribute to be rendered
	 */
	protected function getValueAttribute()
	{
		if(($value=parent::getValueAttribute())==='')
			return $this->getUniqueID();
		else
			return $value;
	}

	/**
	 * @return boolean whether to render javascript.
	 */
	public function getEnableClientScript()
	{
		return $this->getViewState('EnableClientScript',true);
	}

	/**
	 * @param boolean whether to render javascript.
	 */
	public function setEnableClientScript($value)
	{
		$this->setViewState('EnableClientScript',TPropertyValue::ensureBoolean($value),true);
	}

	/**
	 * Renders a radiobutton input element.
	 * @param THtmlWriter the writer for the rendering purpose
	 * @param string checkbox id
	 * @param string onclick js
	 */
	protected function renderInputTag($writer,$clientID,$onclick)
	{
		if($clientID!=='')
			$writer->addAttribute('id',$clientID);
		$writer->addAttribute('type','radio');
		$writer->addAttribute('name',$this->getUniqueGroupName());
		$writer->addAttribute('value',$this->getValueAttribute());
		if(!empty($onclick))
			$writer->addAttribute('onclick',$onclick);
		if($this->getChecked())
			$writer->addAttribute('checked','checked');
		if(!$this->getEnabled(true))
			$writer->addAttribute('disabled','disabled');

		$page=$this->getPage();
		if($this->getEnabled(true)
			&& $this->getEnableClientScript()
			&& $this->getAutoPostBack()
			&& $page->getClientSupportsJavaScript())
		{
			$this->renderClientControlScript($writer);
		}

		if(($accesskey=$this->getAccessKey())!=='')
			$writer->addAttribute('accesskey',$accesskey);
		if(($tabindex=$this->getTabIndex())>0)
			$writer->addAttribute('tabindex',"$tabindex");
		if($attributes=$this->getViewState('InputAttributes',null))
			$writer->addAttributes($attributes);
		$writer->renderBeginTag('input');
		$writer->renderEndTag();
	}

	/**
	 * Renders the client-script code.
	 */
	protected function renderClientControlScript($writer)
	{
		$cs = $this->getPage()->getClientScript();
		$cs->registerPostBackControl($this->getClientClassName(),$this->getPostBackOptions());
	}

	/**
	 * Gets the name of the javascript class responsible for performing postback for this control.
	 * This method overrides the parent implementation.
	 * @return string the javascript class name
	 */
	protected function getClientClassName()
	{
		return 'Prado.WebUI.TRadioButton';
	}
}