Solved: ActionController::ParameterMissing (param is missing or the value is empty)
In Ruby on Rails, strong_params are a necessity to work with ActionController parameters, but sometimes
an exception of ActionController::ParameterMissing is thrown… Why?
The Code
params.require(:message).permit(:text, :author_id)The Exception
ActionController::ParameterMissing (param is missing or the value is empty: message)
The Fix
The error is occurring because our params hash does not include the root key
:message. We can diagnose this issue by utilizing params.inspect in either
an interactive console or printing the output of certain commands.
The command I tend to use most to identify mishaps is params.inspect.
For example, the output of this command might be:
<ActionController::Parameters {"messages"=>{"text"=>"My Message", "author_id"=>1337}} permitted: false>In this case, it appears as though there is a typo in our view! The key was typed
as messages rather than message. The fix is easy, change the view to submit
message instead.