{"record":{"id":"83d3a936c6d637e2","repo":"BabylonJS/Babylon.js","slug":"no-serializer-was-provided-for-a-block-of-type","errorCode":null,"errorMessage":"`No serializer was provided for a block of type ${block.blockType}`","messagePattern":"`No serializer was provided for a block of type (.+?)`","errorType":"exception","errorClass":"Error","httpStatus":null,"severity":"error","filePath":"packages/dev/smartFilters/src/serialization/smartFilterSerializer.ts","lineNumber":70,"sourceCode":"    /**\r\n     * Serializes a SmartFilter to a JSON object of the latest version\r\n     * @param smartFilter - The SmartFilter to serialize\r\n     * @returns The serialized SmartFilter\r\n     */\r\n    public serialize(smartFilter: SmartFilter): SerializedSmartFilterV1 {\r\n        const connections: ISerializedConnectionV1[] = [];\r\n\r\n        const blocks = smartFilter.attachedBlocks.map((block: BaseBlock) => {\r\n            // Serialize the block itself\r\n            const blockClassName = block.getClassName();\r\n            const serializeFn =\r\n                blockClassName === CustomShaderBlock.ClassName\r\n                    ? CustomShaderBlockSerializer\r\n                    : blockClassName === CustomAggregateBlock.ClassName\r\n                      ? DefaultBlockSerializer\r\n                      : this._blockSerializers.get(block.blockType);\r\n            if (!serializeFn) {\r\n                throw new Error(`No serializer was provided for a block of type ${block.blockType}`);\r\n            }\r\n            const serializedBlock: ISerializedBlockV1 = serializeFn(block);\r\n\r\n            // Serialize the connections to the inputs\r\n            block.inputs.forEach((input: ConnectionPoint) => {\r\n                const connectedTo = input.connectedTo;\r\n                if (connectedTo) {\r\n                    const newConnection: ISerializedConnectionV1 = {\r\n                        inputBlock: block.uniqueId,\r\n                        inputConnectionPoint: input.name,\r\n                        outputBlock: connectedTo.ownerBlock.uniqueId,\r\n                        outputConnectionPoint: connectedTo.name,\r\n                    };\r\n                    if (!connections.find((other) => SerializedConnectionPointsEqual(newConnection, other))) {\r\n                        connections.push(newConnection);\r\n                    }\r\n                }\r\n            });\r","sourceCodeStart":52,"sourceCodeEnd":88,"githubUrl":"https://github.com/BabylonJS/Babylon.js/blob/0592b347b8a4ee0236089ea86a749cacfdb266d8/packages/dev/smartFilters/src/serialization/smartFilterSerializer.ts#L52-L88","documentation":"During serialization every block must be mapped to a serializer function. Shader-like custom blocks (InputOutputBlock-derived / CustomShaderBlock) fall back to built-in serializers, but all other custom block types must have been registered in the SmartFilterSerializer's _blockSerializers map. If a block's blockType has no registered serializer, serialization aborts because the block could not be represented in the output JSON.","triggerScenarios":"Calling smartFilterSerializer.serialize() on a filter containing a custom block whose type was never registered with serializer.registerSerializer(blockType, fn), or a blockType renamed so the registration key no longer matches.","commonSituations":"Serializing filters with third-party/custom blocks in a runtime that skipped the registration step, registering under one blockType string while the block instance reports another (name drift after refactors), serializing before custom block modules were imported.","solutions":["Register a serializer for the block type before serializing: serializer.registerSerializer(blockType, CustomBlockSerializer).","Import the module side-effects that register all custom block serializers used by the filter.","Verify block.blockType on the failing block matches the key used at registration (log block.blockType to compare).","Use a DefaultBlockSerializer fallback for simple blocks if a dedicated serializer is unnecessary.","Re-create the serializer instance if registrations were made on a different instance than the one used for serialize()."],"exampleFix":"// before\nconst serializer = new SmartFilterSerializer(smartFilter);\nconst json = serializer.serialize(); // custom type missing\n// after\nconst serializer = new SmartFilterSerializer(smartFilter);\nserializer.registerSerializer(\"MyCustomBlock\", MyCustomBlockSerializer);\nconst json = serializer.serialize();","handlingStrategy":"try-catch","validationCode":"function assertAllBlocksSerializable(smartFilter, serializer) {\n  for (const block of smartFilter.attachedBlocks) {\n    const known = [\"InputBlock\", \"OutputBlock\", \"CustomShaderBlock\", \"CustomAggregateBlock\"]\n      .some((c) => block.getClassName() === c) || serializer.hasSerializer(block.blockType);\n    if (!known) throw new Error(`No serializer registered for ${block.blockType}`);\n  }\n}","typeGuard":"function hasSerializerFor(serializer, block) {\n  return typeof serializer._blockSerializers?.get(block.blockType) === \"function\";\n}","tryCatchPattern":"try {\n  const json = serializer.serialize();\n} catch (e) {\n  const m = e.message.match(/No serializer was provided for a block of type (.+)/);\n  if (m) {\n    serializer.registerSerializer(m[1], DefaultBlockSerializer);\n    return serializer.serialize();\n  }\n  throw e;\n}","preventionTips":["Register a serializer for every custom blockType before serializing.","Import all custom block modules (side-effect registrations) before serialize().","Confirm registration key equals block.blockType exactly.","Bundle-deferred imports can skip registration — verify import order.","Use DefaultBlockSerializer for blocks with default serialization needs."],"tags":["smart-filters","serialization","block-registry","custom-blocks"],"backgroundTag":"unregistered-block-type","analyzedSha":"0592b347b8a4ee0236089ea86a749cacfdb266d8","analyzedAt":"2026-08-30T15:11:20.442Z","schemaVersion":2},"datasetVersion":"2026-08-30T18:17:15.746Z"}