1. from functools import wraps
  2. from http.cookies import SimpleCookie
  3. from typing import Any, Callable, Dict, Optional
  6. def bind_request_header_args(
  7. func: Callable,
  8. header_name: str,
  9. args: list[str],
  10. fallback: Optional[Any] = None,
  11. ) -> Callable:
  12. """
  13. Binds arguments from a request header to a function,
  14. with fallback logic if the header is not present or the arguments are invalid.
  15. """
  17. @wraps(func)
  18. def wrapper(*args_func, **kwargs):
  19. header_value = kwargs.get("headers", {}).get(header_name)
  21. if not header_value:
  22. if fallback is not None:
  23. return fallback # Use fallback value
  24. else:
  25. return func(*args_func, **kwargs) # Call function without header args
  27. try:
  28. # Attempt to parse the header value as a list of arguments
  29. parsed_args = [arg.strip() for arg in header_value.split(",") if arg.strip()]
  30. except Exception:
  31. # Handle potential parsing errors
  32. if fallback is not None:
  33. return fallback
  34. else:
  35. return func(*args_func, **kwargs)
  37. # Check if the parsed arguments are valid
  38. if len(parsed_args) != len(args):
  39. if fallback is not None:
  40. return fallback
  41. else:
  42. return func(*args_func, **kwargs)
  44. # Bind the arguments to the function
  45. bound_args = dict(zip(args, parsed_args))
  46. return func(*args_func, **bound_args, **kwargs)
  48. return wrapper
  51. if __name__ == "__main__":
  52. # Example Usage:
  53. @bind_request_header_args(
  54. header_name="my-args", args=["arg1", "arg2", "arg3"], fallback="default_value"
  55. )
  56. def my_utility_function(arg1: str, arg2: str, arg3: str, extra_arg: str = "default"):
  57. """
  58. A sample utility function that accepts arguments from a request header.
  59. """
  60. print(f"arg1: {arg1}, arg2: {arg2}, arg3: {arg3}, extra_arg: {extra_arg}")
  62. # Test cases
  63. # Test case 1: Header present with all args
  64. headers1 = {"my-args": "value1,value2,value3"}
  65. result1 = my_utility_function(arg1="value1", arg2="value2", arg3="value3")
  66. print(f"Result 1: {result1}")
  68. # Test case 2: Header present with some args missing
  69. headers2 = {"my-args": "value1,value2"}
  70. result2 = my_utility_function(arg1="value1", arg2="value2")
  71. print(f"Result 2: {result2}")
  73. # Test case 3: Header present with extra args
  74. headers3 = {"my-args": "value1,value2,value3,value4"}
  75. result3 = my_utility_function(arg1="value1", arg2="value2", arg3="value3", extra_arg="test")
  76. print(f"Result 3: {result3}")
  78. # Test case 4: Header not present, using fallback
  79. headers4 = {}
  80. result4 = my_utility_function()
  81. print(f"Result 4: {result4}")
  83. # Test case 5: Invalid header value
  84. headers5 = {"my-args": "invalid_value"}
  85. result5 = my_utility_function()
  86. print(f"Result 5: {result5}")

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