1. import json
  2. import re
  4. def validate_api_payload(payload, schema):
  5. """
  6. Validates an API payload against a predefined schema.
  8. Args:
  9. payload (dict): The API payload to validate.
  10. schema (dict): A dictionary defining the expected schema.
  12. Returns:
  13. bool: True if the payload is valid, False otherwise.
  14. """
  16. try:
  17. # Check if the payload is valid JSON
  18. json.loads(json.dumps(payload))
  19. except json.JSONDecodeError:
  20. print("Error: Invalid JSON payload.")
  21. return False
  23. for field, details in schema.items():
  24. if field not in payload:
  25. print(f"Error: Missing field: {field}")
  26. return False
  28. expected_type = details.get("type")
  29. if expected_type:
  30. if expected_type == "string":
  31. if not isinstance(payload[field], str):
  32. print(f"Error: Field '{field}' should be a string.")
  33. return False
  34. elif expected_type == "integer":
  35. if not isinstance(payload[field], int):
  36. print(f"Error: Field '{field}' should be an integer.")
  37. return False
  38. elif expected_type == "float":
  39. if not isinstance(payload[field], (int, float)):
  40. print(f"Error: Field '{field}' should be a float.")
  41. return False
  42. elif expected_type == "boolean":
  43. if not isinstance(payload[field], bool):
  44. print(f"Error: Field '{field}' should be a boolean.")
  45. return False
  46. elif expected_type == "list":
  47. if not isinstance(payload[field], list):
  48. print(f"Error: Field '{field}' should be a list.")
  49. return False
  50. elif expected_type == "dict":
  51. if not isinstance(payload[field], dict):
  52. print(f"Error: Field '{field}' should be a dictionary.")
  53. return False
  55. if "required" in details and field in details["required"] and not payload[field]:
  56. print(f"Error: Field '{field}' is required and cannot be empty.")
  57. return False
  59. if "pattern" in details:
  60. pattern = re.compile(details["pattern"])
  61. if not pattern.match(str(payload[field])):
  62. print(f"Error: Field '{field}' does not match pattern: {details['pattern']}")
  63. return False
  65. return True
  69. if __name__ == '__main__':
  70. # Example Usage
  71. schema = {
  72. "user_id": {"type": "integer"},
  73. "username": {"type": "string"},
  74. "email": {"type": "string", "pattern": r"^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$"},
  75. "is_active": {"type": "boolean"},
  76. "roles": {"type": "list"},
  77. "details": {"type": "dict"}
  78. }
  80. payload1 = {
  81. "user_id": 123,
  82. "username": "john.doe",
  83. "email": "john.doe@example.com",
  84. "is_active": True,
  85. "roles": ["admin", "editor"],
  86. "details": {"created_at": "2023-10-27"}
  87. }
  89. payload2 = {
  90. "username": "jane doe",
  91. "email": "invalid-email",
  92. "is_active": "yes"
  93. }
  95. print(f"Payload 1 is valid: {validate_api_payload(payload1, schema)}")
  96. print(f"Payload 2 is valid: {validate_api_payload(payload2, schema)}")

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