How to Modify Request Parameters through Middleware

Before learning how to modify request parameters, please first understand some details about request parameter input: Request 🔥

Custom Parameter Overriding

The simplest way to modify request parameters is to override client-submitted parameters through custom parameters. Since custom parameters have the highest priority in parameter parsing, when fully retrieving request parameters (not through specific submission methods), custom parameters will override parameters submitted by other methods. This method of modification is common, especially when using standard routing, where parameters are received as a struct object, and the underlying layer retrieves all parameters and then converts them to a struct object.

However, if the user obtains parameters through r.GetQuery, r.GetForm, custom parameter overriding will be ineffective. Methods like r.Get or r.GetRequest for parameter retrieval can also achieve parameter overriding effects.

Modifying Parameters for Specific Request Methods

It's also possible to modify the original parameters in middleware by altering r.URL.RawQuery or r.Body, but after modification, it's necessary to call r.ReloadParams() to indicate that the request parameters will need to be re-parsed in the next retrieval.

Precautions for Modifying Request Body through Middleware

A common issue when modifying r.Body through middleware is that r.Body can only be read once, and subsequent reads will not retrieve the data, which is by the design of the standard library http.Request. In the GoFrame framework's ghttp.Request object, continuous reading of the Body content is allowed using the framework's ghttp.Request GetBody, GetBodyString methods.

However, if you directly read r.Body using the standard library's http.Request object within middleware, it is recommended to reassign r.Body or wrap and reassign it using io.NopCloser to facilitate further reading of Body content by subsequent middleware or processes.