Skip to content

Class ZCL_LLM_COMMON

AI Generated documentation.

Overview

The class zcl_llm_common provides utilities for JSON serialization/deserialization and integration with a custom LLM (Large Language Model) BAdI implementation. Its primary functions include:

  • TO_JSON: Converts ABAP data structures to JSON strings, supporting compression and lowercase key formatting.
  • FROM_JSON: Deserializes JSON strings into ABAP structures with field mapping.
  • GET_LLM_BADI: Returns a reference to the active LLM BAdI implementation.
  • Dynamic JSON handling via a BAdI-resolved implementation class.

Dependencies

  • BAdI: zllm_implementation for runtime JSON implementation resolution.
  • JSON Library: Delegates serialization/deserialization to a class (json_class) provided by the BAdI.
  • Formatting Dependency: Uses /ui2/cl_json for lowercase JSON property naming.

Details

Dynamic JSON Implementation

The class defers JSON processing to an external implementation resolved during initialization: 

classDiagram  
  class zcl_llm_common {  
    +get_llm_badi()  
  }  
  class zllm_implementation {  
    +get_json_impl()  
  }  
  class JSON_Impl["External JSON Class"]  
  zcl_llm_common --> zllm_implementation : BAdI Dependency  
  zllm_implementation --> JSON_Impl : Runtime Resolution  
  zcl_llm_common --> JSON_Impl : Delegates serialize/deserialize
  1. Class Constructor: Fetches the BAdI instance and resolves the JSON handler.
  2. Loose Coupling: Swapping JSON implementations (e.g., for performance or compliance) requires only BAdI reconfiguration.

Key Design Aspects

  • Case Handling: Forces lowercase JSON keys via /ui2/cl_json=>pretty_mode-low_case to ensure consistent property naming.
  • BAdI Control: The LLM BAdI acts as a central extension point for customizing JSON behavior or LLM integrations.
  • Error Transparency: Exceptions from the JSON implementation class propagate directly to callers.

Serialization Logic Flow

sequenceDiagram  
  participant Caller  
  participant zcl_llm_common  
  participant JSON_Impl  
  Caller->>zcl_llm_common: to_json(data)  
  zcl_llm_common->>JSON_Impl: serialize(data, compress)  
  JSON_Impl-->>zcl_llm_common: JSON string  
  zcl_llm_common-->>Caller: Return result
  • Compression: When enabled, removes whitespace from the output JSON.
  • Type Preservation: Relies on the JSON implementation to map ABAP types (e.g., DATS, TIMS) correctly.

Testing Implications

  • BAdI Mocking: Tests require a stubbed BAdI providing a test-safe JSON implementation.
  • Roundtrip Stability: Successful tests implicitly validate that the resolved JSON implementation supports symmetric conversions.
  • Empty JSON Handling: Explicit checks ensure edge cases like {} are not treated as errors.