Reduce duplication in Comparison helpers

src/Comparison/AbstractComparisonHelper.php

@@ -0,0 +1,49 @@
+<?php
+
+namespace JustBlackBird\HandlebarsHelpers\Comparison;
+
+use Handlebars\Context;
+use Handlebars\Helper as HelperInterface;
+use Handlebars\Template;
+
+/**
+ * Contains base functionality for all helpers related with comparison.
+ *
+ * @author Dmitriy Simushev <simushevds@gmail.com>
+ */
+abstract class AbstractComparisonHelper implements HelperInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function execute(Template $template, Context $context, $args, $source)
+    {
+        $resolved_args = array();
+        foreach ($template->parseArguments($args) as $arg) {
+            $resolved_args[] = $context->get($arg);
+        }
+
+        if ($this->evaluateCondition($resolved_args)) {
+            $template->setStopToken('else');
+            $buffer = $template->render($context);
+            $template->setStopToken(false);
+        } else {
+            $template->setStopToken('else');
+            $template->discard();
+            $template->setStopToken(false);
+            $buffer = $template->render($context);
+        }
+
+        return $buffer;
+    }
+
+    /**
+     * Evaluates condition based on helper's arguments.
+     *
+     * This is a template method which must be overriden in inherited helpers.
+     *
+     * @param array $args List of resolved arguments passed to the helper.
+     * @return bool Indicates if the condition is true or false.
+     */
+    abstract protected function evaluateCondition($args);
+}

src/Comparison/IfAnyHelper.php

@@ -10,10 +10,8 @@
 
 namespace JustBlackBird\HandlebarsHelpers\Comparison;
 
-use Handlebars\Context;
 use Handlebars\Helper as HelperInterface;
 use Handlebars\StringWrapper;
-use Handlebars\Template;
 
 /**
  * Conditional helper that checks if at least one argumet can be treated as
@@ -30,24 +28,20 @@ use Handlebars\Template;
  *
  * @author Dmitriy Simushev <simushevds@gmail.com>
  */
-class IfAnyHelper implements HelperInterface
+class IfAnyHelper extends AbstractComparisonHelper implements HelperInterface
 {
     /**
      * {@inheritdoc}
      */
-    public function execute(Template $template, Context $context, $args, $source)
+    protected function evaluateCondition($args)
     {
-        $parsed_args = $template->parseArguments($args);
+        if (count($args) == 0) {
-        if (count($parsed_args) == 0) {
             throw new \InvalidArgumentException(
                 '"ifAny" helper expects at least one argument.'
             );
         }
 
-        $condition = false;
+        foreach ($args as $value) {
-        foreach ($parsed_args as $parsed_arg) {
-            $value = $context->get($parsed_arg);
-
             if ($value instanceof StringWrapper) {
                 // Casting any object of \Handlebars\StringWrapper will have
                 // false positive result even for those with empty internal
@@ -57,22 +51,10 @@ class IfAnyHelper implements HelperInterface
             }
 
             if ($value) {
-                $condition = true;
+                return true;
-                break;
             }
         }
 
-        if ($condition) {
+        return false;
-            $template->setStopToken('else');
-            $buffer = $template->render($context);
-            $template->setStopToken(false);
-        } else {
-            $template->setStopToken('else');
-            $template->discard();
-            $template->setStopToken(false);
-            $buffer = $template->render($context);
-        }
-
-        return $buffer;
     }
 }

src/Comparison/IfEqualHelper.php

@@ -10,9 +10,7 @@
 
 namespace JustBlackBird\HandlebarsHelpers\Comparison;
 
-use Handlebars\Context;
 use Handlebars\Helper as HelperInterface;
-use Handlebars\Template;
 
 /**
  * Conditional helper that checks if two values are equal or not.
@@ -28,33 +26,19 @@ use Handlebars\Template;
  *
  * @author Dmitriy Simushev <simushevds@gmail.com>
  */
-class IfEqualHelper implements HelperInterface
+class IfEqualHelper extends AbstractComparisonHelper implements HelperInterface
 {
     /**
      * {@inheritdoc}
      */
-    public function execute(Template $template, Context $context, $args, $source)
+    protected function evaluateCondition($args)
     {
-        $parsed_args = $template->parseArguments($args);
+        if (count($args) != 2) {
-        if (count($parsed_args) != 2) {
             throw new \InvalidArgumentException(
                 '"ifEqual" helper expects exactly two arguments.'
             );
         }
 
-        $condition = ($context->get($parsed_args[0]) == $context->get($parsed_args[1]));
+        return ($args[0] == $args[1]);
-
-        if ($condition) {
-            $template->setStopToken('else');
-            $buffer = $template->render($context);
-            $template->setStopToken(false);
-        } else {
-            $template->setStopToken('else');
-            $template->discard();
-            $template->setStopToken(false);
-            $buffer = $template->render($context);
-        }
-
-        return $buffer;
     }
 }

src/Comparison/IfEvenHelper.php

@@ -10,9 +10,7 @@
 
 namespace JustBlackBird\HandlebarsHelpers\Comparison;
 
-use Handlebars\Context;
 use Handlebars\Helper as HelperInterface;
-use Handlebars\Template;
 
 /**
  * Conditional helper that checks if specified argument is even or not.
@@ -28,33 +26,19 @@ use Handlebars\Template;
  *
  * @author Dmitriy Simushev <simushevds@gmail.com>
  */
-class IfEvenHelper implements HelperInterface
+class IfEvenHelper extends AbstractComparisonHelper implements HelperInterface
 {
     /**
      * {@inheritdoc}
      */
-    public function execute(Template $template, Context $context, $args, $source)
+    protected function evaluateCondition($args)
     {
-        $parsed_args = $template->parseArguments($args);
+        if (count($args) != 1) {
-        if (count($parsed_args) != 1) {
             throw new \InvalidArgumentException(
                 '"ifEven" helper expects exactly one argument.'
             );
         }
 
-        $condition = ($context->get($parsed_args[0]) % 2 == 0);
+        return ($args[0] % 2 == 0);
-
-        if ($condition) {
-            $template->setStopToken('else');
-            $buffer = $template->render($context);
-            $template->setStopToken(false);
-        } else {
-            $template->setStopToken('else');
-            $template->discard();
-            $template->setStopToken(false);
-            $buffer = $template->render($context);
-        }
-
-        return $buffer;
     }
 }

src/Comparison/IfOddHelper.php

@@ -10,9 +10,7 @@
 
 namespace JustBlackBird\HandlebarsHelpers\Comparison;
 
-use Handlebars\Context;
 use Handlebars\Helper as HelperInterface;
-use Handlebars\Template;
 
 /**
  * Conditional helper that checks if specified argument is odd or not.
@@ -28,33 +26,19 @@ use Handlebars\Template;
  *
  * @author Dmitriy Simushev <simushevds@gmail.com>
  */
-class IfOddHelper implements HelperInterface
+class IfOddHelper extends AbstractComparisonHelper implements HelperInterface
 {
     /**
      * {@inheritdoc}
      */
-    public function execute(Template $template, Context $context, $args, $source)
+    protected function evaluateCondition($args)
     {
-        $parsed_args = $template->parseArguments($args);
+        if (count($args) != 1) {
-        if (count($parsed_args) != 1) {
             throw new \InvalidArgumentException(
                 '"ifOdd" helper expects exactly one argument.'
             );
         }
 
-        $condition = ($context->get($parsed_args[0]) % 2 == 1);
+        return ($args[0] % 2 == 1);
-
-        if ($condition) {
-            $template->setStopToken('else');
-            $buffer = $template->render($context);
-            $template->setStopToken(false);
-        } else {
-            $template->setStopToken('else');
-            $template->discard();
-            $template->setStopToken(false);
-            $buffer = $template->render($context);
-        }
-
-        return $buffer;
     }
 }

src/Comparison/UnlessEqualHelper.php

@@ -10,9 +10,7 @@
 
 namespace JustBlackBird\HandlebarsHelpers\Comparison;
 
-use Handlebars\Context;
 use Handlebars\Helper as HelperInterface;
-use Handlebars\Template;
 
 /**
  * Conditional helper that checks if two values are equal or not.
@@ -28,33 +26,19 @@ use Handlebars\Template;
  *
  * @author Dmitriy Simushev <simushevds@gmail.com>
  */
-class UnlessEqualHelper implements HelperInterface
+class UnlessEqualHelper extends AbstractComparisonHelper implements HelperInterface
 {
     /**
      * {@inheritdoc}
      */
-    public function execute(Template $template, Context $context, $args, $source)
+    protected function evaluateCondition($args)
     {
-        $parsed_args = $template->parseArguments($args);
+        if (count($args) != 2) {
-        if (count($parsed_args) != 2) {
             throw new \InvalidArgumentException(
                 '"unlessEqual" helper expects exactly two arguments.'
             );
         }
 
-        $condition = ($context->get($parsed_args[0]) == $context->get($parsed_args[1]));
+        return ($args[0] != $args[1]);
-
-        if (!$condition) {
-            $template->setStopToken('else');
-            $buffer = $template->render($context);
-            $template->setStopToken(false);
-        } else {
-            $template->setStopToken('else');
-            $template->discard();
-            $template->setStopToken(false);
-            $buffer = $template->render($context);
-        }
-
-        return $buffer;
     }
 }