firmware-base/docs-c/core/json.md

title	description	keywords
JSON Utilities	Utility functions for parsing JSON data in embedded applications	JSON ArduinoJson parsing ESP32 embedded

JSON Utilities

Path: src/utils/json_utils.h

Revision History:

• Initial documentation

A collection of inline utility functions for parsing JSON data in embedded applications. These functions provide a consistent way to extract values from JSON objects, with built-in type validation and error reporting.

REQUIREMENTS

• ArduinoJson library
• ArduinoLog library

PROVIDES

• JsonUtils namespace containing utility functions:
  • parseJsonFieldUint32: Parses a 32-bit unsigned integer from JSON
  • parseJsonFieldUint8: Parses an 8-bit unsigned integer from JSON
  • parseJsonFieldBool: Parses a boolean value from JSON

FEATURES

• Type validation for JSON field parsing
• Maintains default values when fields are missing or of incorrect type
• Debug logging for parsing errors
• Consistent parsing interface across different data types

DEPENDENCIES

• ArduinoJson
• ArduinoLog

graph TD
    JsonUtils --> ArduinoJson
    JsonUtils --> ArduinoLog

BEHAVIOUR

graph TD
    Start([Parse JSON Field]) --> CheckField{Field exists?}
    CheckField -- Yes --> CheckType{Correct type?}
    CheckField -- No --> UseDefault[Use default value]
    CheckType -- Yes --> AssignValue[Assign parsed value]
    CheckType -- No --> LogWarning[Log warning] --> UseDefault
    AssignValue --> End([End])
    UseDefault --> End

TODOS

PERFORMANCE

• Consider providing batch parsing functions to reduce parsing overhead for multiple fields
• Evaluate memory usage when parsing large JSON objects

SECURITY

• Currently no validation for value ranges; consider adding range validation options
• Implement protection against malformed JSON that could lead to buffer overflows

COMPLIANCE

• Ensure all error messages follow consistent formatting standards
• Consider adding more documentation for compliance with project coding standards

RECOMMENDATIONS

• Add support for additional data types (e.g., float, string)
• Consider a more structured approach to error handling (e.g., error codes or exceptions)
• Add functions for array parsing and nested object traversal
• Provide examples of common JSON parsing scenarios