This middleware is available in Express v4. This is a built-in middleware ext js 6 getting started pdf in Express.
It parses incoming requests with JSON payloads and is based on body-parser. Returns middleware that only parses JSON and only looks at requests where the Content-Type header matches the type option. This parser accepts any Unicode encoding of the body and supports automatic inflation of gzip and deflate encodings. Content-Type was not matched, or an error occurred. String may not be a function and instead a string or other user-input. The following table describes the properties of the optional options object. Controls the maximum request body size.
The reviver option is passed directly to JSON. You can find more information on this argument in the MDN documentation about JSON. This is used to determine what media type the middleware will parse. This option can be a string, array of strings, or a function.
Buffer of the raw request body and encoding is the encoding of the request. The parsing can be aborted by throwing an error. It serves static files and is based on serve-static. NOTE: For best results, use a reverse proxy cache to improve performance of serving static assets. The root argument specifies the root directory from which to serve static assets. The function determines the file to serve by combining req.
The following table describes the properties of the options object. Sets file extension fallbacks: If a file is not found, search for files with the specified extensions and serve the first one found. Let client errors fall-through as unhandled requests, otherwise forward a client error. Enable or disable the immutable directive in the Cache-Control response header. Sends the specified directory index file.
Set to false to disable directory indexing. Set the Last-Modified header to the last modified date of the file on the OS. Set the max-age property of the Cache-Control header in milliseconds or a string in ms format. Function for setting HTTP headers to serve with the file.
For more information, see Serving static files in Express. NOTE: With the default value, it will not ignore files in a directory that begins with a dot. Set this option to true so you can map multiple physical directories to the same web address or for routes to fill in non-existent files. Use false if you have mounted this middleware at a path designed to be strictly a single file system directory, which allows for short-circuiting 404s for less overhead. This middleware will also reply to all methods. Headers For this option, specify a function to set custom response headers.
Alterations to the headers must occur synchronously. Here is an example of using the express. The optional options parameter specifies the behavior of the router. If the parent and the child have conflicting param names, the child’s value take precedence. It parses incoming requests with urlencoded payloads and is based on body-parser. Returns middleware that only parses urlencoded bodies and only looks at requests where the Content-Type header matches the type option. This parser accepts only UTF-8 encoding of the body and supports automatic inflation of gzip and deflate encodings.
URL-encoded format, allowing for a JSON-like experience with URL-encoded. For more information, please see the qs library. This option controls the maximum number of parameters that are allowed in the URL-encoded data. If a request contains more parameters than this value, an error will be raised. Application The app object conventionally denotes the Express application. The Express application object can be referred from the request object and the response object as req. Once set, the value of app.