View Source Phoenix.MissingParamError exception (Phoenix v1.7.0-rc.3)
Raised when a key is expected to be present in the request parameters, but is not.
This exception is raised by Phoenix.Controller.scrub_params/2 which:
- Checks to see if the required_key is present (can be empty)
- Changes all empty parameters to nils ("" -> nil)
If you are seeing this error, you should handle the error and surface it to the end user. It means that there is a parameter missing from the request.