SerializableValue: new helper class

library/Director/Data/InvalidDataException.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace Icinga\Module\Director\Data;
+
+use InvalidArgumentException;
+
+class InvalidDataException extends InvalidArgumentException
+{
+    /**
+     * @param string $expected
+     * @param mixed $value
+     */
+    public function __construct($expected, $value)
+    {
+        parent::__construct("$expected expected, got " . static::getPhpType($value));
+    }
+
+    public static function getPhpType($var)
+    {
+        if (is_object($var)) {
+            return get_class($var);
+        }
+
+        return gettype($var);
+    }
+}

library/Director/Data/Serializable.php

@@ -0,0 +1,10 @@
+<?php
+
+namespace Icinga\Module\Director\Data;
+
+use JsonSerializable;
+
+interface Serializable extends JsonSerializable
+{
+    public static function fromSerialization($value);
+}

library/Director/Data/SerializableValue.php

@@ -0,0 +1,89 @@
+<?php
+
+namespace Icinga\Module\Director\Data;
+
+use InvalidArgumentException;
+use JsonSerializable;
+use stdClass;
+use function get_class;
+use function gettype;
+use function is_array;
+use function is_object;
+use function is_scalar;
+
+class SerializableValue implements Serializable
+{
+    protected $value = [];
+
+    /**
+     * @param stdClass|array $object
+     * @return static
+     */
+    public static function fromSerialization($value)
+    {
+        $self = new static;
+        static::assertSerializableValue($value);
+        $self->value = $value;
+
+        return $self;
+    }
+
+    public static function wantSerializable($value)
+    {
+        if ($value instanceof SerializableValue) {
+            return $value;
+        }
+
+        return static::fromSerialization($value);
+    }
+
+    /**
+     * TODO: Check whether json_encode() is faster
+     *
+     * @param mixed $value
+     * @return bool
+     */
+    protected static function assertSerializableValue($value)
+    {
+        if ($value === null || is_scalar($value)) {
+            return true;
+        }
+        if (is_object($value)) {
+            if ($value instanceof JsonSerializable) {
+                return true;
+            }
+
+            if ($value instanceof stdClass) {
+                foreach ((array) $value as $val) {
+                    static::assertSerializableValue($val);
+                }
+
+                return true;
+            }
+        }
+
+        if (is_array($value)) {
+            foreach ($value as $val) {
+                static::assertSerializableValue($val);
+            }
+
+            return true;
+        }
+
+        throw new InvalidArgumentException('Serializable value expected, got ' . static::getPhpType($value));
+    }
+
+    protected static function getPhpType($var)
+    {
+        if (is_object($var)) {
+            return get_class($var);
+        }
+
+        return gettype($var);
+    }
+
+    public function jsonSerialize()
+    {
+        return $this->value;
+    }
+}