Web API

Golang Web API Framework

Purpose

The Project "webapi" is a Go Module with the purpose of creating feature rich web apis with little effort. It extends the functionality of the net/http package and adds a Router that implements the net/http.Handler interface. The Router can be used in the context of a net/http.Server to route HTTP(S) requests to a specific handler by using regex matchers that are defined in the powerful, yet easy to understand Path-To-Regexp Syntax. With Path-To-Regexp, the Router is also capable of parsing Path Parameters that are defined in the route's matcher string, (see example or test cases). The path parameters will be passed as a map[string]string to any of the given request handlers. The framework defines new Handler functions that are more flexible than net/http.HandlerFunc's and allow the programmer to create chained handlers with customizable alternative paths (e.g. Error Handlers). See examples for more info...

Usage

Simply go get the package and start coding:

go get https://github.com/markoczy/webapi

Here's a minimalistic usage example:

// Create Fallback handler (for unmatched requests)
fallback404 := webapi.NewErrorHandler(http.StatusNotFound, "404 not found")
// Create Router
router := webapi.NewRouter(fallback404)
// Create Handler by chaining Handler functions
handler := webapi.NewHandler(
    // Handler function 1
    func(w http.ResponseWriter, r *webapi.ParsedRequest, next func() webapi.Handler) webapi.Handler {
        // (optional) Handle errors
        if r.PathParams["name"] == "abc" {
            return webapi.NewErrorHandler(http.StatusBadRequest, "Your name is not 'abc' ;-)") 
        }
        // Write data (or do other stuff)
        w.Write([]byte("Hello, " + r.PathParams["name"]))
        return next()
    }, 
    // Handler function 2
    func(w http.ResponseWriter, r *webapi.ParsedRequest, next func() webapi.Handler) webapi.Handler {
        // do stuff for handler 2 (e.g. Fill Headers)
        return next()
    },
)
// Register Handler
router.Handle(http.MethodGet, "/hello/:name", handler)
// Serve HTTP
http.ListenAndServe(":7890", router)
//
// cURL Results:
// `curl localhost:7890/hello/John+Doe` returns Hello, John Doe
// `curl localhost:7890/hello/abc` returns Bad Request

For Path matching syntax, check github.com/soongo/path-to-regexp, for more examples, check the test cases.

Dependencies

• PathToRegexp: github.com/soongo/path-to-regexp (License: MIT)