stop_for_http_problem {httpproblems}

Signal an Error Caused by an HTTP Problem

Description

The various ⁠stop_for_*()⁠ functions leverage R's condition system to signal an error with a custom type embedding the "Problem Details" structure defined in RFC 7807.

They can be used for reporting errors from HTTP APIs in a standard way.

There are also helper methods for the most common HTTP problems: HTTP 400 Bad Request, 404 Not Found, 401 Unauthorized, 403 Forbidden, 409 Conflict, and 500 Internal Server Error.

Usage

stop_for_http_problem(
  detail = NULL,
  status = 500L,
  type = NULL,
  title = NULL,
  instance = NULL,
  ...
)

stop_for_bad_request(detail = NULL, instance = NULL, ...)

stop_for_unauthorized(detail = NULL, instance = NULL, ...)

stop_for_forbidden(detail = NULL, instance = NULL, ...)

stop_for_not_found(detail = NULL, instance = NULL, ...)

stop_for_conflict(detail = NULL, instance = NULL, ...)

stop_for_internal_server_error(detail = NULL, instance = NULL, ...)

Arguments

detail

A human-readable string giving more detail about the error, if possible.

status

The HTTP status code appropriate for the response.

type

A URL pointing to human-readable documentation for this type of problem. When NULL, the type is generated based on the status code; see http_problem_types() for a list of the defaults.

title

A "short, human-readable summary of the problem type". When NULL, the title is generated based on the status code; see http_problem_types() for a list of the defaults.

instance

A URL that identifies the specific occurrence of the problem, if possible. When NULL this field is simply excluded.

...

Additional fields added to the problem as Extension Members.

Value

These functions call stop() with a custom condition (with class "http_problem_error"), so they do not return a value.

See Also

http_problem for creating the structure directly.

Examples

tryCatch(
  stop_for_bad_request("Parameter 'id' must be a number."),
  error = function(e) {
    str(e)
  }
)