Middleware for collecting log messages issued during execution of the current request.

This adds a requestlog property to the application object with an items property. During execution of a request items contains an array containing all the log messages issued for the request. Log messages are represented as arrays in the format [time, level, name, message].

During request execution, the requestlog property also defines a property called start containing the time the execution started.

By default, messages are appended to the response if its Content-Type is text/html. This can be controlled using the app.requestlog.append boolean flag.