Added vendor/ directory for Composer's installed files

vendor/alexgarrett/violin/examples/advanced/extending.php

@@ -0,0 +1,77 @@
+<?php
+
+/**
+ * Violin example. Extending.
+ * 
+ * You can extend the Violin class to create your own validator,
+ * making it easier to keep everything in one place, and more
+ * importantly, the ability to pass dependencies into the
+ * class.
+ *
+ * This example checks a specfic value isn't already taken
+ * within a table in your database.
+ */
+
+require '../../vendor/autoload.php';
+
+//-- Validator.php
+
+use Violin\Violin;
+
+class Validator extends Violin
+{
+    protected $db;
+
+    public function __construct(PDO $db)
+    {
+        $this->db = $db;
+
+        $this->addRuleMessage('unique', 'That {field} is already taken.');
+    }
+
+    /**
+     * Check if a value already exists in a database table.
+     * 
+     * @param  mixed $value
+     * @param  array $input
+     * @param  array $args
+     * 
+     * @return bool
+     */
+    public function validate_unique($value, $input, $args)
+    {
+        $table  = $args[0];
+        $column = $args[1];
+        $value  = trim($value);
+
+        $exists = $this->db->prepare("
+            SELECT count(*) as count
+            FROM {$table}
+            WHERE {$column} = :value
+        ");
+
+        $exists->execute([
+            'value' => $value
+        ]);
+
+        return ! (bool) $exists->fetchObject()->count;
+    }
+}
+
+//-- Any other file
+
+// Some database dependency
+$db = new PDO('mysql:dbname=project;host=localhost', 'root', 'root');
+
+$v = new Validator($db);
+
+$v->validate([
+    'username'  => ['alex', 'required|alpha|min(3)|max(20)|unique(users, username)'],
+    'email'     => ['alex@codecourse.com', 'required|email|unique(users, email)']
+]);
+
+if ($v->passes()) {
+    // Passed
+} else {
+    var_dump($v->errors()->all());
+}