Method deserializeBlock

apps/sim/serializer/index.ts:339–391

(serializedBlock: SerializedBlock)

  }

  private deserializeBlock(serializedBlock: SerializedBlock): BlockState {
    const blockType = serializedBlock.metadata?.id
    if (!blockType) {
      throw new Error(`Invalid block type: ${serializedBlock.metadata?.id}`)
    }

    // Special handling for subflow blocks (loops, parallels, etc.)
    if (blockType === 'loop' || blockType === 'parallel') {
      return {
        id: serializedBlock.id,
        type: blockType,
        name: serializedBlock.metadata?.name || (blockType === 'loop' ? 'Loop' : 'Parallel'),
        position: serializedBlock.position,
        subBlocks: {}, // Loops and parallels don't have traditional subBlocks
        outputs: serializedBlock.outputs,
        enabled: serializedBlock.enabled ?? true,
        data: serializedBlock.config.params, // Preserve the data (parallelType, count, etc.)
      }
    }

    const blockConfig = getBlock(blockType)
    if (!blockConfig) {
      throw new Error(`Invalid block type: ${blockType}`)
    }

    const subBlocks: Record<string, any> = {}
    blockConfig.subBlocks.forEach((subBlock) => {
      subBlocks[subBlock.id] = {
        id: subBlock.id,
        type: subBlock.type,
        value: serializedBlock.config.params[subBlock.id] ?? null,
      }
    })

    // Migration logic for agent blocks: Transform old systemPrompt/userPrompt to messages array
    if (blockType === 'agent') {
      migrateAgentParamsToMessages(serializedBlock.config.params, subBlocks, serializedBlock.id)
    }

    return {
      id: serializedBlock.id,
      type: blockType,
      name: serializedBlock.metadata?.name || blockConfig.name,
      position: serializedBlock.position,
      subBlocks,
      outputs: serializedBlock.outputs,
      enabled: true,
      triggerMode:
        serializedBlock.config?.params?.triggerMode === true ||
        serializedBlock.metadata?.category === 'triggers',
      advancedMode: serializedBlock.config?.params?.advancedMode === true,
    }
  }
}

/** A canonical pair where the active member is empty but an inactive member holds a value that will be silently dropped. */