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Diffstat (limited to 'framework/Web/UI/WebControls/TConditional.php')
| -rw-r--r-- | framework/Web/UI/WebControls/TConditional.php | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/framework/Web/UI/WebControls/TConditional.php b/framework/Web/UI/WebControls/TConditional.php new file mode 100644 index 00000000..70eedf6d --- /dev/null +++ b/framework/Web/UI/WebControls/TConditional.php @@ -0,0 +1,142 @@ +<?php
+/**
+ * TConditional class file.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @link http://www.pradosoft.com/
+ * @copyright Copyright © 2005-2007 PradoSoft
+ * @license http://www.pradosoft.com/license/
+ * @version $Id$
+ * @package System.Web.UI.WebControls
+ */
+
+/**
+ * TConditional class.
+ *
+ * TConditional displays appropriate content based on the evaluation result
+ * of a PHP expression specified via {@link setCondition Condition}.
+ * If the result is true, it instantiates the template {@link getTrueTemplate TrueTemplate};
+ * otherwise, the template {@link getFalseTemplate FalseTemplate} is instantiated.
+ * The PHP expression is evaluated right before {@link onInit} stage of the control lifecycle.
+ *
+ * Since {@link setCondition Condition} is evaluated at a very early stage, it is recommended
+ * you set {@link setCondition Condition} in template and the expression should not refer to
+ * objects that are available on or after {@link onInit} lifecycle.
+ *
+ * A typical usage of TConditional is shown as following:
+ * <code>
+ * <com:TConditional Condition="$this->User->IsGuest">
+ * <prop:TrueTemplate>
+ * <a href="path/to/login">Login</a>
+ * </prop:TrueTemplate>
+ * <prop:FalseTemplate>
+ * <a href="path/to/logout">Logout</a>
+ * </prop:FalseTemplate>
+ * </com:TConditional>
+ * </code>
+ *
+ * TConditional is very light. It instantiates either {@link getTrueTemplate TrueTemplate}
+ * or {@link getFalseTemplate FalseTemplate}, but never both. And the condition is evaluated only once.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @version $Id$
+ * @package System.Web.UI.WebControls
+ * @since 3.1.1
+ */
+class TConditional extends TControl
+{
+ private $_condition='true';
+ private $_trueTemplate;
+ private $_falseTemplate;
+ private $_creatingChildren=false;
+
+ /**
+ * Processes an object that is created during parsing template.
+ * This method overrides the parent implementation by removing
+ * all contents enclosed in the template tag.
+ * @param string|TComponent text string or component parsed and instantiated in template
+ * @see createdOnTemplate
+ */
+ public function addParsedObject($object)
+ {
+ if($this->_creatingChildren)
+ parent::addParsedObject($object);
+ }
+
+ /**
+ * Creates child controls.
+ * This method overrides the parent implementation. It evaluates {@link getCondition Condition}
+ * and instantiate the corresponding template.
+ */
+ public function createChildControls()
+ {
+ $this->_creatingChildren=true;
+ $result=true;
+ try
+ {
+ $result=$this->evaluateExpression($this->_condition);
+ }
+ catch(Exception $e)
+ {
+ throw new TInvalidDataValueException('conditional_condition_invalid',$this->_condition,$e->getMessage());
+ }
+ if($result)
+ {
+ if($this->_trueTemplate)
+ $this->_trueTemplate->instantiateIn($this);
+ }
+ else if($this->_falseTemplate)
+ $this->_falseTemplate->instantiateIn($this);
+ $this->_creatingChildren=false;
+ }
+
+ /**
+ * @return string the PHP expression used for determining which template to use. Defaults to 'true', meaning using TrueTemplate.
+ */
+ public function getCondition()
+ {
+ return $this->_condition;
+ }
+
+ /**
+ * @param string the PHP expression used for determining which template to use.
+ */
+ public function setCondition($value)
+ {
+ $this->_condition=TPropertyValue::ensureString($value);
+ }
+
+ /**
+ * @return ITemplate the template applied when {@link getCondition Condition} is true.
+ */
+ public function getTrueTemplate()
+ {
+ return $this->_trueTemplate;
+ }
+
+ /**
+ * @param ITemplate the template applied when {@link getCondition Condition} is true.
+ */
+ public function setTrueTemplate(ITemplate $value)
+ {
+ $this->_trueTemplate=$value;
+ }
+
+ /**
+ * @return ITemplate the template applied when {@link getCondition Condition} is false.
+ */
+ public function getFalseTemplate()
+ {
+ return $this->_falseTemplate;
+ }
+
+ /**
+ * @param ITemplate the template applied when {@link getCondition Condition} is false.
+ */
+ public function setFalseTemplate(ITemplate $value)
+ {
+ $this->_falseTemplate=$value;
+ }
+}
+
+?>
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