Add "replace" helper

src/Helpers.php

@@ -40,6 +40,7 @@ class Helpers extends BaseHelpers
         $this->add('lowercase', new String\LowercaseHelper());
         $this->add('uppercase', new String\UppercaseHelper());
         $this->add('repeat', new String\RepeatHelper());
+        $this->add('replace', new String\ReplaceHelper());
         $this->add('truncate', new String\TruncateHelper());
 
         // Layout helpers

src/String/Helpers.php

@@ -29,6 +29,7 @@ class Helpers extends BaseHelpers
         $this->add('lowercase', new LowercaseHelper());
         $this->add('uppercase', new UppercaseHelper());
         $this->add('repeat', new RepeatHelper());
+        $this->add('replace', new ReplaceHelper());
         $this->add('truncate', new TruncateHelper());
     }
 }

src/String/ReplaceHelper.php

@@ -0,0 +1,51 @@
+<?php
+/*
+ * This file is part of Handlebars.php Helpers Set
+ *
+ * (c) Dmitriy Simushev <simushevds@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace JustBlackBird\HandlebarsHelpers\String;
+
+use Handlebars\Context;
+use Handlebars\Helper as HelperInterface;
+use Handlebars\Template;
+
+/**
+ * Helper for replacing substrings.
+ *
+ * Usage:
+ * ```handlebars
+ *   {{#replace search replacement}}Target string to search in.{{/replace}}
+ * ```
+ *
+ * Arguments:
+ *  - "search": The value that should be replaced.
+ *  - "replacement": The value that should be use as a replacement.
+ *
+ * @author Dmitriy Simushev <simushevds@gmail.com>
+ */
+class ReplaceHelper implements HelperInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function execute(Template $template, Context $context, $args, $source)
+    {
+        $parsed_args = $template->parseArguments($args);
+        if (count($parsed_args) != 2) {
+            throw new \InvalidArgumentException(
+                '"replace" helper expects exactly two arguments.'
+            );
+        }
+
+        $search = $context->get($parsed_args[0]);
+        $replacement = $context->get($parsed_args[1]);
+        $subject = (string)$template->render($context);
+
+        return str_replace($search, $replacement, $subject);
+    }
+}

tests/HelpersTest.php

@@ -52,6 +52,7 @@ class HelpersTest extends \PHPUnit_Framework_TestCase
             array('lowercase', '\\JustBlackBird\\HandlebarsHelpers\\String\\LowercaseHelper'),
             array('uppercase', '\\JustBlackBird\\HandlebarsHelpers\\String\\UppercaseHelper'),
             array('repeat', '\\JustBlackBird\\HandlebarsHelpers\\String\\RepeatHelper'),
+            array('replace', '\\JustBlackBird\\HandlebarsHelpers\\String\\ReplaceHelper'),
             array('truncate', '\\JustBlackBird\\HandlebarsHelpers\\String\\TruncateHelper'),
 
             // Layout helpers

tests/String/HelpersTest.php

@@ -41,6 +41,7 @@ class HelpersTest extends \PHPUnit_Framework_TestCase
             array('lowercase', '\\JustBlackBird\\HandlebarsHelpers\\String\\LowercaseHelper'),
             array('uppercase', '\\JustBlackBird\\HandlebarsHelpers\\String\\UppercaseHelper'),
             array('repeat', '\\JustBlackBird\\HandlebarsHelpers\\String\\RepeatHelper'),
+            array('replace', '\\JustBlackBird\\HandlebarsHelpers\\String\\ReplaceHelper'),
             array('truncate', '\\JustBlackBird\\HandlebarsHelpers\\String\\TruncateHelper'),
         );
     }

tests/String/ReplaceHelperTest.php

@@ -0,0 +1,80 @@
+<?php
+/*
+ * This file is part of Handlebars.php Helpers Set
+ *
+ * (c) Dmitriy Simushev <simushevds@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace JustBlackBird\HandlebarsHelpers\Tests\String;
+
+use JustBlackBird\HandlebarsHelpers\String\ReplaceHelper;
+
+/**
+ * Test class for "replace" helper.
+ *
+ * @author Dmitriy Simushev <simushevds@gmail.com>
+ */
+class ReplaceHelperTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * Tests that strings are repeated properly.
+     *
+     * @dataProvider replaceProvider
+     */
+    public function testReplace($string, $search, $replacement, $result)
+    {
+        $helpers = new \Handlebars\Helpers(array('replace' => new ReplaceHelper()));
+        $engine = new \Handlebars\Handlebars(array('helpers' => $helpers));
+
+        $this->assertEquals(
+            $engine->render(
+                '{{#replace search replacement}}{{str}}{{/replace}}',
+                array('str' => $string, 'search' => $search, 'replacement' => $replacement)
+            ),
+            $result
+        );
+    }
+
+    /**
+     * A data provider for testReplace method.
+     */
+    public function replaceProvider()
+    {
+        return array(
+            array('abcd', 'b', '', 'acd'),
+            array('abcd', 'xyz', '', 'abcd'),
+            array('abcd', '', 'asd', 'abcd'),
+        );
+    }
+
+    /**
+     * Tests that exception is thrown if wrong number of arguments is used.
+     *
+     * @expectedException InvalidArgumentException
+     * @dataProvider wrongArgumentsSetProvider
+     */
+    public function testArgumentsCount($template)
+    {
+        $helpers = new \Handlebars\Helpers(array('replace' => new ReplaceHelper()));
+        $engine = new \Handlebars\Handlebars(array('helpers' => $helpers));
+
+        $engine->render($template, array());
+    }
+
+    /**
+     * A data provider for testArgumentsCount method.
+     */
+    public function wrongArgumentsSetProvider()
+    {
+        return array(
+            // Not enough arguments
+            array('{{#replace}}str{{/replace}}'),
+            array('{{#replace "serach"}}str{{/replace}}'),
+            // Too much arguments
+            array('{{#replace "search" "replacement" "asd"}}str{{/replace}}'),
+        );
+    }
+}