1 files changed, 149 insertions, 0 deletions
diff --git a/src/Components/Reference.php b/src/Components/Reference.php
new file mode 100644
index 0000000..fef8fa4
--- /dev/null
+++ b/src/Components/Reference.php
@@ -0,0 +1,149 @@
+<?php
+
+/**
+ * `REFERENCES` keyword parser.
+ *
+ * @package    SqlParser
+ * @subpackage Components
+ */
+namespace SqlParser\Components;
+
+use SqlParser\Context;
+use SqlParser\Component;
+use SqlParser\Parser;
+use SqlParser\Token;
+use SqlParser\TokensList;
+
+/**
+ * `REFERENCES` keyword parser.
+ *
+ * @category   Keywords
+ * @package    SqlParser
+ * @subpackage Components
+ * @author     Dan Ungureanu <udan1107@gmail.com>
+ * @license    http://opensource.org/licenses/GPL-2.0 GNU Public License
+ */
+class Reference extends Component
+{
+
+    /**
+     * All references options.
+     *
+     * @var array
+     */
+    public static $REFERENCES_OPTIONS = array(
+        'MATCH'                         => array(1, 'var'),
+        'ON DELETE'                     => array(2, 'var'),
+        'ON UPDATE'                     => array(3, 'var'),
+    );
+
+    /**
+     * The referenced table.
+     *
+     * @var string
+     */
+    public $table;
+
+    /**
+     * The referenced columns.
+     *
+     * @var array
+     */
+    public $columns;
+
+    /**
+     * The options of the referencing.
+     *
+     * @var OptionsArray
+     */
+    public $options;
+
+    /**
+     * Constructor.
+     *
+     * @param string          $table   The name of the table referenced.
+     * @param array           $columns The columns referenced.
+     * @param OptionsArray $options The options.
+     */
+    public function __construct($table = null, array $columns = array(), $options = null)
+    {
+        $this->table = $table;
+        $this->columns = $columns;
+        $this->options = $options;
+    }
+
+    /**
+     * @param Parser     $parser  The parser that serves as context.
+     * @param TokensList $list    The list of tokens that are being parsed.
+     * @param array      $options Parameters for parsing.
+     *
+     * @return Reference
+     */
+    public static function parse(Parser $parser, TokensList $list, array $options = array())
+    {
+        $ret = new Reference();
+
+        /**
+         * The state of the parser.
+         *
+         * Below are the states of the parser.
+         *
+         *      0 ----------------------[ table ]---------------------> 1
+         *
+         *      1 ---------------------[ columns ]--------------------> 2
+         *
+         *      2 ---------------------[ options ]--------------------> -1
+         *
+         * @var int
+         */
+        $state = 0;
+
+        for (; $list->idx < $list->count; ++$list->idx) {
+            /**
+             * Token parsed at this moment.
+             * @var Token $token
+             */
+            $token = $list->tokens[$list->idx];
+
+            // End of statement.
+            if ($token->type === Token::TYPE_DELIMITER) {
+                break;
+            }
+
+            // Skipping whitespaces and comments.
+            if (($token->type === Token::TYPE_WHITESPACE) || ($token->type === Token::TYPE_COMMENT)) {
+                continue;
+            }
+
+            if ($state === 0) {
+                $ret->table = $token->value;
+                $state = 1;
+            } elseif ($state === 1) {
+                $ret->columns = ArrayObj::parse($parser, $list)->values;
+                $state = 2;
+            } elseif ($state === 2) {
+                $ret->options = OptionsArray::parse($parser, $list, static::$REFERENCES_OPTIONS);
+                ++$list->idx;
+                break;
+            }
+
+        }
+
+        --$list->idx;
+        return $ret;
+    }
+
+    /**
+     * @param Reference $component The component to be built.
+     *
+     * @return string
+     */
+    public static function build($component)
+    {
+        return trim(
+            Context::escape($component->table)
+            . ' (' . implode(', ', Context::escape($component->columns)) . ') '
+            . OptionsArray::build($component->options)
+        );
+    }
+}