Skip to content

Class ZCL_LLM_SO_JS

AI Generated documentation.

Overview

The class ZCL_LLM_SO_JS is a default implementation for generating JSON schemas from ABAP data structures. It implements the interface ZIF_LLM_SO to provide structured output definitions for LLM interactions.

Key Public Methods:

  • ZIF_LLM_SO~SET_SCHEMA: Generates a JSON schema from an ABAP data descriptor. Validates and maps ABAP types (structures, tables, primitives) to JSON schema constructs.
  • ZIF_LLM_SO~GET_SCHEMA: Returns the generated schema as a JSON string.
  • ZIF_LLM_SO~GET_DATATYPE: Provides access to the ABAP data descriptor used for schema generation.

Supports nested structures, tables, primitive types, enums, custom descriptions, and validation for unsupported types (e.g., DATS).

Dependencies

  • ABAP Runtime Type Services (RTTS): Uses CL_ABAP_*DESCR classes for type introspection.
  • Exceptions: Raises ZCX_LLM_VALIDATION for unsupported types or invalid configurations.
  • Interface: Implements ZIF_LLM_SO for schema definition contracts.

Details

Schema Generation Flow

flowchart TD  
    A[set_schema] --> B[Process Data Descriptor]  
    B --> C{Type?}  
    C -->|Structure| D[Process Structure]  
    C -->|Table| E[Process Table]  
    C -->|Element| F[Process Element]  
    D --> G[Recurse for Components]  
    E --> H[Process Line Type]  
    F --> I[Map ABAP Type to JSON]  
    G --> C  
    H --> C

Key Logic:

  1. Type Handling:
  2. Structures: Converted to JSON object types. Fields are recursively processed, and required properties are auto-generated.
  3. Tables: Mapped to JSON array types. Line types are processed to define items.

  4. Primitives: ABAP types (e.g., INT, STRING, ABAP_BOOL) are mapped to JSON equivalents. CHAR1 fields are validated for boolean compliance.

  5. Customization:

  6. Descriptions: Injected via descriptions parameter in SET_SCHEMA. Supports nested paths (e.g., field-subfield).

  7. Enums: Defined via enum_values in descriptions, generating JSON enum constraints.

  8. Validation:

  9. Unsupported types (e.g., DATS, invalid CHAR1) trigger ZCX_LLM_VALIDATION.
  10. Schema syntax integrity is enforced (e.g., additionalProperties: false, strict ordering for multiple tables).

Field Context Tracking

The field_info structure tracks nested paths (e.g., root-field-subfield) to align custom descriptions and enum values with the correct schema nodes. This enables:

  • Context-aware error messages.
  • Precise injection of metadata into deeply nested schemas.

Boolean Detection

ABAP fields are mapped to JSON booleans only if:

  • Type is CHAR1 (length 1).
  • Absolute name matches known boolean types (e.g., ABAP_BOOL).
    Other CHAR1 fields raise ZCX_LLM_VALIDATION (tested in test_char1_nonbool).

Recursive Processing

Methods like PROCESS_STRUCTURE and PROCESS_TABLE recursively resolve nested types, ensuring correct schema composition for complex hierarchies (e.g., tables of nested structures).