Allow undefined property handler to return a string to override varia…

…ble name

This lets us add e.g. camel case mapping handlers.

Resolves: #198
Resolves: #183
Resolves: #150
Resolves: #149
Resolves: #29

README.rst

@@ -391,6 +391,28 @@ __ http://php.net/manual/en/language.types.callable.php
     $jm->undefinedPropertyHandler = 'setUndefinedProperty';
     $jm->map(...);
 
+Or if you would let JsonMapper handle the setter for you, you can return a string
+from the ``$undefinedPropertyHandler`` which will be used as property name.
+
+.. code:: php
+
+    /**
+     * Handle undefined properties during JsonMapper::map()
+     *
+     * @param object $object    Object that is being filled
+     * @param string $propName  Name of the unknown JSON property
+     * @param mixed  $jsonValue JSON value of the property
+     *
+     * @return void
+     */
+    function fixPropName($object, $propName, $jsonValue)
+    {
+        return ucfirst($propName);
+    }
+
+    $jm = new JsonMapper();
+    $jm->undefinedPropertyHandler = 'fixPropName';
+    $jm->map(...);
 
 Missing properties
 ------------------

src/JsonMapper.php

@@ -177,18 +177,26 @@ public function map($json, $object)
                         . ' in object of type ' . $strClassName
                     );
                 } else if ($this->undefinedPropertyHandler !== null) {
-                    call_user_func(
+                    $undefinedPropertyKey = call_user_func(
                         $this->undefinedPropertyHandler,
                         $object, $key, $jvalue
                     );
+
+                    if (is_string($undefinedPropertyKey)) {
+                        list($hasProperty, $accessor, $type, $isNullable)
+                            = $this->inspectProperty($rc, $undefinedPropertyKey);
+                    }
                 } else {
                     $this->log(
                         'info',
                         'Property {property} does not exist in {class}',
                         array('property' => $key, 'class' => $strClassName)
                     );
                 }
-                continue;
+
+                if (!$hasProperty) {
+                    continue;
+                }
             }
 
             if ($accessor === null) {

tests/NameMappingTest.php

@@ -0,0 +1,52 @@
+<?php
+
+declare(strict_types=1);
+
+use PHPUnit\Framework\TestCase;
+
+require_once 'JsonMapperTest/Simple.php';
+
+class NameMappingTest extends TestCase
+{
+    public function testItSetKeysIfReturnedByUndefinedPropertyHandler(): void
+    {
+        $jm = new JsonMapper();
+        $jm->undefinedPropertyHandler = function (
+            JsonMapperTest_Simple $object,
+            string $key,
+            $value
+        ): string {
+            return lcfirst(
+                str_replace(
+                    ' ', '', ucwords(str_replace(array('_', '-'), ' ', $key))
+                )
+            );
+        };
+
+        /** @var JsonMapperTest_Simple $sn */
+        $sn = $jm->map(
+            json_decode('{"hyphen_value": "abc"}'),
+            new JsonMapperTest_Simple()
+        );
+
+        self::assertSame('abc', $sn->hyphenValue);
+    }
+
+    public function testItDoesNotMapKeyIfUndefinedPropertyHandlerDoesNotReturnValue(): void
+    {
+        $jm = new JsonMapper();
+        $jm->undefinedPropertyHandler = function (
+            JsonMapperTest_Simple $object,
+            string $key,
+            $value
+        ): void {};
+
+        /** @var JsonMapperTest_Simple $sn */
+        $sn = $jm->map(
+            json_decode('{"hyphen_value": "abc"}'),
+            new JsonMapperTest_Simple()
+        );
+
+        self::assertNull($sn->hyphenValue);
+    }
+}