app.on('mount', callback(parent)) The mount event is fired on a sub-app, when it is mounted on a parent app. The parent app is

req.app This property holds a reference to the instance of the Express application that is using the middleware. If

res.headersSent Boolean property that indicates if the app sent HTTP headers for the response.

Events

Define error-handling middleware functions in the same way as other middleware functions, except error-handling functions have four arguments instead of three: (err,

res.redirect([status,] path) Redirects to the URL derived from the specified path, with specified status, a positive

res.status(code) Sets the HTTP status for the response. It is a chainable alias of Node’s

res.clearCookie(name [, options]) Clears the cookie specified by name. For details about the options object, see

req.method Contains a string corresponding to the HTTP method of the request: GET, POST, PUT, and so

app.get(path, callback [, callback ...]) Routes HTTP GET requests to the specified path with the specified callback functions. For more information