package middleware
import (
"bytes"
"fmt"
"html/template"
"net/http"
"path"
)
// SwaggerUIOpts configures the SwaggerUI middleware
type SwaggerUIOpts struct {
// BasePath for the API, defaults to: /
BasePath string
// Path combines with BasePath to construct the path to the UI, defaults to: "docs".
Path string
// SpecURL is the URL of the spec document.
//
// Defaults to: /swagger.json
SpecURL string
// Title for the documentation site, default to: API documentation
Title string
// Template specifies a custom template to serve the UI
Template string
// OAuthCallbackURL the url called after OAuth2 login
OAuthCallbackURL string
// The three components needed to embed swagger-ui
// SwaggerURL points to the js that generates the SwaggerUI site.
//
// Defaults to: https://unpkg.com/swagger-ui-dist/swagger-ui-bundle.js
SwaggerURL string
SwaggerPresetURL string
SwaggerStylesURL string
Favicon32 string
Favicon16 string
}
// EnsureDefaults in case some options are missing
func (r *SwaggerUIOpts) EnsureDefaults() {
r.ensureDefaults()
if r.Template == "" {
r.Template = swaggeruiTemplate
}
}
func (r *SwaggerUIOpts) EnsureDefaultsOauth2() {
r.ensureDefaults()
if r.Template == "" {
r.Template = swaggerOAuthTemplate
}
}
func (r *SwaggerUIOpts) ensureDefaults() {
common := toCommonUIOptions(r)
common.EnsureDefaults()
fromCommonToAnyOptions(common, r)
// swaggerui-specifics
if r.OAuthCallbackURL == "" {
r.OAuthCallbackURL = path.Join(r.BasePath, r.Path, "oauth2-callback")
}
if r.SwaggerURL == "" {
r.SwaggerURL = swaggerLatest
}
if r.SwaggerPresetURL == "" {
r.SwaggerPresetURL = swaggerPresetLatest
}
if r.SwaggerStylesURL == "" {
r.SwaggerStylesURL = swaggerStylesLatest
}
if r.Favicon16 == "" {
r.Favicon16 = swaggerFavicon16Latest
}
if r.Favicon32 == "" {
r.Favicon32 = swaggerFavicon32Latest
}
}
// SwaggerUI creates a middleware to serve a documentation site for a swagger spec.
//
// This allows for altering the spec before starting the http listener.
func SwaggerUI(opts SwaggerUIOpts, next http.Handler) http.Handler {
opts.EnsureDefaults()
pth := path.Join(opts.BasePath, opts.Path)
tmpl := template.Must(template.New("swaggerui").Parse(opts.Template))
assets := bytes.NewBuffer(nil)
if err := tmpl.Execute(assets, opts); err != nil {
panic(fmt.Errorf("cannot execute template: %w", err))
}
return serveUI(pth, assets.Bytes(), next)
}
const (
swaggerLatest = "https://unpkg.com/swagger-ui-dist/swagger-ui-bundle.js"
swaggerPresetLatest = "https://unpkg.com/swagger-ui-dist/swagger-ui-standalone-preset.js"
swaggerStylesLatest = "https://unpkg.com/swagger-ui-dist/swagger-ui.css"
swaggerFavicon32Latest = "https://unpkg.com/swagger-ui-dist/favicon-32x32.png"
swaggerFavicon16Latest = "https://unpkg.com/swagger-ui-dist/favicon-16x16.png"
swaggeruiTemplate = `
{{ .Title }}
`
)