Adding the "closures as policies" handling2.2

2 files changed, 57 insertions, 2 deletions

diff --git a/docs/policies.md b/docs/policies.md
index 2ab5a5b..a3312a3 100644
--- a/docs/policies.md
+++ b/docs/policies.md
@@ -85,3 +85,28 @@ if ($policy->evaluate($user) === true) {
 ?>
 ```
 
+## Using Closures as Policies
+
+You can also use the same structure of you'd like to define policies as closures, letting you do a bit more programmatic evaluation of the data provided. The same rules apply above to how they're evaluated, you just define them differently:
+
+```php
+<?php
+
+Gatekeeper::createPolicy([
+	'name' => 'eval-closure',
+	'description' => 'Using a closure to validate policy',
+	'expression' => function($data) {
+		return ($data->username === 'ccornutt');
+	};
+]);
+
+if (Gatekeeper::evaluatePolicy('eval-closure', $user) === true) {
+	echo "Sweet success!";
+}
+?>
+```
+
+Here we've define the check for a `username` match as a closure and run an evaluation on it.
+
+> **NOTE:** Any checks that happen to have the same name as a policy that lives in the database will be overridden by a closure-based check (which may be advantageous depending on your needs).
+
diff --git a/src/Psecio/Gatekeeper/Gatekeeper.php b/src/Psecio/Gatekeeper/Gatekeeper.php
index 5741252..4af534b 100644
--- a/src/Psecio/Gatekeeper/Gatekeeper.php
+++ b/src/Psecio/Gatekeeper/Gatekeeper.php
@@ -45,6 +45,12 @@ class Gatekeeper
     private static $config = array();
 
     /**
+     * Current set of policies (callback versions)
+     * @var array
+     */
+    private static $policies = array();
+
+    /**
      * Initialize the Gatekeeper instance, set up environment file and PDO connection
      *
      * @param string $envPath Environment file path (defaults to CWD)
@@ -588,7 +594,31 @@ class Gatekeeper
      */
     public static function evaluatePolicy($name, $data)
     {
-        $policy = Gatekeeper::findPolicyByName($name);
-        return $policy->evaluate($data);
+        // See if it's a closure policy first
+        if (array_key_exists($name, self::$policies)) {
+            $policy = self::$policies[$name];
+            $result = $policy($data);
+            return (!is_bool($result)) ? false : $result;
+        } else {
+            $policy = Gatekeeper::findPolicyByName($name);
+            return $policy->evaluate($data);
+        }
+    }
+
+    /**
+     * Allow for the creation of a policy as a callback too
+     *
+     * @param array $policy Policy settings
+     * @return boolean Success/fail of policy creation
+     */
+    public static function createPolicy(array $policy)
+    {
+        if (is_callable($policy['expression'])) {
+            $name = $policy['name'];
+            self::$policies[$name] = $policy['expression'];
+            return true;
+        } else {
+            return self::handleCreate('createPolicy', array($policy));
+        }
     }
 }
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