New features in 3.x

Application

• app.head() support
• app.locals.use(callback) view-specific parallel middleware to expose dynamic local variables
• app.render(name[, options], callback) to render app-level views

Request

• req.accepts(type) improved
• req.accepted array of parsed Accept values sorted by quality
• req.acceptsCharset(charset) added
• req.acceptedCharsets array of parsed Accept-Charset values sorted by quality
• req.acceptsLanguage(lang) added
• req.acceptedLanguages array of parsed Accept-Language values sorted by quality
• req.signedCookies object containing signed cookies

Response

• res.cache(str[, options]) Cache-Control helper
• res.signedCookie() set a signed cookie
• res.set(field, value) set field value
• res.set(obj) set several field values
• res.type(path) alias of previous res.contentType(path)
• JSON cookie support