YAML handler update.

Changelog excerpt:
- Added support for !php/const tags to the YAML handler.

Author: Maikuolan

.tests/YAMLTest.php

@@ -606,7 +606,6 @@
     exit($ExitCode);
 }
 
-$Object->AllowObjectUnserialize = true;
 $Object->AllowObjectSerialize = true;
 require_once $ClassesDir . 'Context.php';
 $Actual = new \Maikuolan\Common\Context();
@@ -625,9 +624,20 @@
     exit($ExitCode);
 }
 
+$Object->AllowObjectUnserialize = true;
 $ProcessResult = $Object->process($Reconstructed, $Object->Data);
 $ExitCode++;
 if ($ProcessResult !== true || !isset($Object->Data['Serialisation test']) || !($Object->Data['Serialisation test'] instanceof \Maikuolan\Common\Context)) {
     echo 'Test failed: ' . $Case . ':L' . __LINE__ . '().' . PHP_EOL;
     exit($ExitCode);
 }
+
+$RawYAML = 'Foo: "bar"
+Baz: !php/const PHP_INT_MAX
+';
+$Object = new \Maikuolan\Common\YAML($RawYAML);
+$ExitCode++;
+if (!isset($Object->Data['Baz']) || $Object->Data['Baz'] !== PHP_INT_MAX) {
+    echo 'Test failed: ' . $Case . ':L' . __LINE__ . '().' . PHP_EOL;
+    exit($ExitCode);
+}

Changelog.txt

@@ -20,7 +20,7 @@ found at:
   when enabled via the appropriate properties of the instance. When
   reconstructing strings, if a string isn't UTF-8 (e.g., binary sourced from
   images, archives, etc), it'll be rendered as base-64 with the !!binary tag
-  attached.
+  attached. Added support for !php/const tags to the YAML handler.
 
 === Version/Release 2.14.3 ===
 PATCH RELEASE.

_docs/YAML.md

@@ -708,6 +708,7 @@ The overall specification is quite extensive, and writing this documentation tak
 __Tags (specific methods implemented)__ | __Description__
 :--|:--
 `!flatten` | Flattens a multidimensional array down to a single depth (similar to merge, but rather than merging the array to the parent collection, it merges all the sub-arrays into the array being worked upon).
+`!php/const` | Returns a PHP constant (e.g., `!php/const PHP_INT_MAX`).
 `!php/object` | Allows unserialisation of PHP serialised data (when `AllowObjectUnserialize` is set to `true`; is set to `false` by default).
 __Tags (directly invokes PHP functions at `coerce`)__ | __Description__
 `!abs` | Uses PHP's `abs()` function to process the entry.

src/YAML.php

@@ -1153,11 +1153,9 @@ private function coerce($Value, bool $EnforceScalar, string $Tag)
                 return $Arr;
             }
 
-            /**
-             * Unserialising a PHP object.
-             */
-            if ($Tag === 'php/object' && $this->AllowObjectUnserialize && is_string($Value) && $Value !== '') {
-                return unserialize($Value);
+            /** Unserialising a PHP object. */
+            if ($Tag === 'php/object') {
+                return $this->AllowObjectUnserialize && is_string($Value) && $Value !== '' ? unserialize($Value) : $Value;
             }
 
             /** For extending with other non-scalar coercion. */
@@ -1249,10 +1247,12 @@ private function coerce($Value, bool $EnforceScalar, string $Tag)
          * @link https://yaml.org/type/binary.html
          */
         if ($Tag === '!binary') {
-            if ($Value === '' || !is_string($Value)) {
-                return '';
-            }
-            return base64_decode(preg_replace('~\s~', '', $Value));
+            return is_string($Value) && $Value !== '' ? base64_decode(preg_replace('~\s~', '', $Value)) : '';
+        }
+
+        /** PHP constants. */
+        if ($Tag === 'php/const') {
+            return is_string($Value) && $Value !== '' && defined($Value) ? constant($Value) : $Value;
         }
 
         /** For extending with other scalar coercion. */