Added placeholders classes

src/main/php/com/selfcoders/phputils/placeholders/Method.php

@@ -0,0 +1,24 @@
+<?php
+namespace com\selfcoders\phputils\placeholders;
+
+class Method
+{
+    /**
+     * @var object
+     */
+    public $object;
+    /**
+     * @var string
+     */
+    public $method;
+
+    /**
+     * @param object $object
+     * @param string $method
+     */
+    public function __construct($object, $method)
+    {
+        $this->object = $object;
+        $this->method = $method;
+    }
+}

src/main/php/com/selfcoders/phputils/placeholders/Placeholder.php

@@ -0,0 +1,60 @@
+<?php
+namespace com\selfcoders\phputils\placeholders;
+
+use com\selfcoders\phputils\placeholders\exception\InvalidPlaceholderNameException;
+
+class Placeholder
+{
+    const NAME_REGEX = "/\\{\\{([a-zA-Z0-9_\-]+)\\}\\}/";
+    const NAME_PREFIX = "{{";
+    const NAME_SUFFIX = "}}";
+
+    /**
+     * @var string
+     */
+    private $name;
+    /**
+     * @var mixed
+     */
+    private $value;
+
+    /**
+     * @param string $name
+     * @param mixed $value
+     * @throws InvalidPlaceholderNameException
+     */
+    public function __construct($name, $value)
+    {
+        if (!self::validate($name)) {
+            throw new InvalidPlaceholderNameException($name);
+        }
+
+        $this->name = $name;
+        $this->value = $value;
+    }
+
+    /**
+     * @param string $name
+     * @return bool
+     */
+    public static function validate($name)
+    {
+        return (bool)preg_match(self::NAME_REGEX, self::NAME_PREFIX . $name . self::NAME_SUFFIX);
+    }
+
+    /**
+     * @return string
+     */
+    public function getName()
+    {
+        return $this->name;
+    }
+
+    /**
+     * @return mixed
+     */
+    public function getValue()
+    {
+        return $this->value;
+    }
+}

src/main/php/com/selfcoders/phputils/placeholders/Placeholders.php

@@ -0,0 +1,88 @@
+<?php
+namespace com\selfcoders\phputils\placeholders;
+
+use ArrayObject;
+use com\selfcoders\phputils\placeholders\exception\UndefinedPlaceholderException;
+
+class Placeholders extends ArrayObject
+{
+    /**
+     * @param Placeholder $placeholder
+     */
+    public function append($placeholder)
+    {
+        /**
+         * @var $thisPlaceholder Placeholder
+         */
+        foreach ($this as &$thisPlaceholder) {
+            if (strtolower($thisPlaceholder->getName()) == strtolower($placeholder->getName())) {
+                $thisPlaceholder = $placeholder;
+                return;
+            }
+        }
+
+        parent::append($placeholder);
+    }
+
+    /**
+     * @param Placeholders $placeholders
+     */
+    public function appendAll(Placeholders $placeholders)
+    {
+        /**
+         * @var $placeholder Placeholder
+         */
+        foreach ($placeholders as $placeholder) {
+            $this->append($placeholder);
+        }
+    }
+
+    /**
+     * @param string $name
+     * @return Placeholder|null
+     */
+    public function getPlaceholder($name)
+    {
+        /**
+         * @var $thisPlaceholder Placeholder
+         */
+        foreach ($this as $thisPlaceholder) {
+            if (strtolower($thisPlaceholder->getName()) == strtolower($name)) {
+                return $thisPlaceholder;
+            }
+        }
+
+        return null;
+    }
+
+    /**
+     * @param string $name
+     * @return mixed
+     * @throws UndefinedPlaceholderException
+     */
+    public function getValueForPlaceholder($name)
+    {
+        $placeholder = $this->getPlaceholder($name);
+        if ($placeholder === null) {
+            throw new UndefinedPlaceholderException($name);
+        }
+
+        $value = $placeholder->getValue();
+        if ($value instanceof Method) {
+            return $value->object->{$value->method}();
+        } else {
+            return $value;
+        }
+    }
+
+    /**
+     * @param $string
+     * @return mixed
+     */
+    public function replace($string)
+    {
+        return preg_replace_callback(Placeholder::NAME_REGEX, function ($matches) {
+            return $this->getValueForPlaceholder($matches[1]);
+        }, $string);
+    }
+}

src/main/php/com/selfcoders/phputils/placeholders/exception/InvalidPlaceholderNameException.php

@@ -0,0 +1,28 @@
+<?php
+namespace com\selfcoders\phputils\placeholders\exception;
+
+class InvalidPlaceholderNameException extends PlaceholderException
+{
+    /**
+     * @var string
+     */
+    private $name;
+
+    /**
+     * @param string $name
+     */
+    public function __construct($name)
+    {
+        $this->name = $name;
+
+        parent::__construct("Invalid placeholder name: " . $name);
+    }
+
+    /**
+     * @return string
+     */
+    public function getName()
+    {
+        return $this->name;
+    }
+}

src/main/php/com/selfcoders/phputils/placeholders/exception/PlaceholderException.php

@@ -0,0 +1,8 @@
+<?php
+namespace com\selfcoders\phputils\placeholders\exception;
+
+use Exception;
+
+class PlaceholderException extends Exception
+{
+}

src/main/php/com/selfcoders/phputils/placeholders/exception/UndefinedPlaceholderException.php

@@ -0,0 +1,28 @@
+<?php
+namespace com\selfcoders\phputils\placeholders\exception;
+
+class UndefinedPlaceholderException extends PlaceholderException
+{
+    /**
+     * @var string
+     */
+    private $placeholder;
+
+    /**
+     * @param string $placeholder
+     */
+    public function __construct($placeholder)
+    {
+        $this->placeholder = $placeholder;
+
+        parent::__construct("Placeholder '" . $placeholder . "' is not defined");
+    }
+
+    /**
+     * @return string
+     */
+    public function getPlaceholder()
+    {
+        return $this->placeholder;
+    }
+}

src/test/php/com/selfcoders/phputils/placeholders/PlaceholderTest.php

@@ -0,0 +1,19 @@
+<?php
+namespace com\selfcoders\phputils\placeholders;
+
+use PHPUnit_Framework_TestCase;
+
+class PlaceholderTest extends PHPUnit_Framework_TestCase
+{
+    public function testValidate()
+    {
+        $this->assertTrue(Placeholder::validate("FOO"));
+        $this->assertTrue(Placeholder::validate("bar"));
+        $this->assertTrue(Placeholder::validate("fooBar"));
+        $this->assertTrue(Placeholder::validate("foo-bar"));
+        $this->assertTrue(Placeholder::validate("foo_bar"));
+        $this->assertFalse(Placeholder::validate("foo+bar"));
+        $this->assertFalse(Placeholder::validate("foo~bar"));
+        $this->assertFalse(Placeholder::validate("Foo!Bar"));
+    }
+}

src/test/php/com/selfcoders/phputils/placeholders/PlaceholdersTest.php

@@ -0,0 +1,63 @@
+<?php
+namespace com\selfcoders\phputils\placeholders;
+
+use PHPUnit_Framework_TestCase;
+
+class PlaceholdersTest extends PHPUnit_Framework_TestCase
+{
+    public function testSingle()
+    {
+        $placeholders = new Placeholders;
+
+        $placeholders->append(new Placeholder("word", "world"));
+
+        $this->assertEquals("Hello world", $placeholders->replace("Hello {{word}}"));
+    }
+
+    public function testMultiple()
+    {
+        $placeholders = new Placeholders;
+
+        $placeholders->append(new Placeholder("word", "string"));
+        $placeholders->append(new Placeholder("firstWord", "This"));
+
+        $this->assertEquals("This is a longer string", $placeholders->replace("{{firstWord}} is a longer {{word}}"));
+    }
+
+    public function testGetValueForPlaceholder()
+    {
+        $placeholders = new Placeholders;
+
+        $placeholders->append(new Placeholder("foo", "bar"));
+        $placeholders->append(new Placeholder("hello", "world"));
+
+        $this->assertEquals("bar", $placeholders->getValueForPlaceholder("foo"));
+        $this->assertEquals("world", $placeholders->getValueForPlaceholder("hello"));
+    }
+
+    public function testGetPlaceholder()
+    {
+        $fooPlaceholder = new Placeholder("foo", "bar");
+        $helloPlaceholder = new Placeholder("hello", "world");
+
+        $placeholders = new Placeholders;
+
+        $placeholders->append($fooPlaceholder);
+        $placeholders->append($helloPlaceholder);
+
+        $this->assertEquals($fooPlaceholder, $placeholders->getPlaceholder("foo"));
+        $this->assertEquals($helloPlaceholder, $placeholders->getPlaceholder("hello"));
+    }
+
+    /**
+     * @expectedException \com\selfcoders\phputils\placeholders\exception\UndefinedPlaceholderException
+     */
+    public function testUndefinedPlaceholder()
+    {
+        $placeholders = new Placeholders;
+
+        $placeholders->append(new Placeholder("foo", "bar"));
+
+        $placeholders->replace("foo {{bar}}");
+    }
+}