diff options
Diffstat (limited to 'MLEB/Translate/src/Utilities/Json/JsonCodec.php')
-rw-r--r-- | MLEB/Translate/src/Utilities/Json/JsonCodec.php | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/MLEB/Translate/src/Utilities/Json/JsonCodec.php b/MLEB/Translate/src/Utilities/Json/JsonCodec.php new file mode 100644 index 00000000..2d1bb693 --- /dev/null +++ b/MLEB/Translate/src/Utilities/Json/JsonCodec.php @@ -0,0 +1,89 @@ +<?php +declare( strict_types = 1 ); + +namespace MediaWiki\Extension\Translate\Utilities\Json; + +use FormatJson; +use InvalidArgumentException; +use JsonSerializable; +use Wikimedia\Assert\Assert; + +/** + * Helper class to serialize/unserialize things to/from JSON. + * This class, and related classes can be removed once Translate needs to support only + * MW >= 1.36. We can then use the JsonCodec class present in core. + * + * Differences between JsonCodec in the core: + * - unserialize only supports strings + * - does not detect non serializable data + * + * See Change-Id: I5433090ae8e2b3f2a4590cc404baf838025546ce + * @license GPL-2.0-or-later + * @since 2020.12 + */ +class JsonCodec { + public const TYPE_ANNOTATION = '_type_'; + + public function unserialize( ?string $json, string $expectedClass = null ) { + Assert::precondition( + !$expectedClass || is_subclass_of( $expectedClass, JsonUnserializable::class ), + '$expectedClass parameter must be subclass of JsonUnserializable, got ' . $expectedClass + ); + + $jsonStatus = FormatJson::parse( $json, FormatJson::FORCE_ASSOC ); + if ( !$jsonStatus->isGood() ) { + // TODO: in PHP 7.3, we can use JsonException + throw new InvalidArgumentException( "Bad JSON: {$jsonStatus}" ); + } + $json = $jsonStatus->getValue(); + + if ( !$this->canMakeNewFromValue( $json ) ) { + if ( $expectedClass ) { + throw new InvalidArgumentException( 'JSON did not have ' . self::TYPE_ANNOTATION ); + } + return $json; + } + + $class = $json[self::TYPE_ANNOTATION]; + if ( !class_exists( $class ) || !is_subclass_of( $class, JsonUnserializable::class ) ) { + throw new InvalidArgumentException( "Invalid target class {$class}" ); + } + + $obj = $class::newFromJsonArray( $json ); + if ( $expectedClass && !$obj instanceof $expectedClass ) { + $actualClass = get_class( $obj ); + throw new InvalidArgumentException( "Expected {$expectedClass}, got {$actualClass}" ); + } + return $obj; + } + + public function serialize( $value ): string { + if ( $value instanceof JsonSerializable ) { + $json = $value->jsonSerialize(); + } else { + $json = FormatJson::encode( $value, false, FormatJson::ALL_OK ); + } + + if ( !$json ) { + throw new InvalidArgumentException( + 'Failed to encode JSON. Error ' . json_last_error_msg() + ); + } + + return $json; + } + + /** Is it likely possible to make a new instance from $json serialization? */ + private function canMakeNewFromValue( $json ): bool { + $classAnnotation = self::TYPE_ANNOTATION; + if ( is_array( $json ) ) { + return array_key_exists( $classAnnotation, $json ); + } + if ( is_object( $json ) ) { + return $json->$classAnnotation; + } + return false; + } +} + +class_alias( JsonCodec::class, '\MediaWiki\Extensions\Translate\JsonCodec' ); |