package middleware
import (
"bytes"
"fmt"
"html/template"
"net/http"
"path"
)
// RedocOpts configures the Redoc middlewares
type RedocOpts struct {
// BasePath for the UI path, defaults to: /
BasePath string
// Path combines with BasePath for the full UI path, defaults to: docs
Path string
// SpecURL the url to find the spec for
SpecURL string
// RedocURL for the js that generates the redoc site, defaults to: https://cdn.jsdelivr.net/npm/redoc/bundles/redoc.standalone.js
RedocURL string
// Title for the documentation site, default to: API documentation
Title string
}
// EnsureDefaults in case some options are missing
func (r *RedocOpts) EnsureDefaults() {
if r.BasePath == "" {
r.BasePath = "/"
}
if r.Path == "" {
r.Path = "docs"
}
if r.SpecURL == "" {
r.SpecURL = "/swagger.json"
}
if r.RedocURL == "" {
r.RedocURL = redocLatest
}
if r.Title == "" {
r.Title = "API documentation"
}
}
// Redoc creates a middleware to serve a documentation site for a swagger spec.
// This allows for altering the spec before starting the http listener.
//
func Redoc(opts RedocOpts, next http.Handler) http.Handler {
opts.EnsureDefaults()
pth := path.Join(opts.BasePath, opts.Path)
tmpl := template.Must(template.New("redoc").Parse(redocTemplate))
buf := bytes.NewBuffer(nil)
_ = tmpl.Execute(buf, opts)
b := buf.Bytes()
return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
if r.URL.Path == pth {
rw.Header().Set("Content-Type", "text/html; charset=utf-8")
rw.WriteHeader(http.StatusOK)
_, _ = rw.Write(b)
return
}
if next == nil {
rw.Header().Set("Content-Type", "text/plain")
rw.WriteHeader(http.StatusNotFound)
_, _ = rw.Write([]byte(fmt.Sprintf("%q not found", pth)))
return
}
next.ServeHTTP(rw, r)
})
}
const (
redocLatest = "https://cdn.jsdelivr.net/npm/redoc/bundles/redoc.standalone.js"
redocTemplate = `
{{ .Title }}
`
)