adds swagger ui as documentation option

Signed-off-by: Ivan Porto Carrero <ivan@flanders.co.nz>
go-openapi · Jul 18, 2020 · 5fc6d79 · 5fc6d79
1 parent 095c1f4
commit 5fc6d79
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Showing 3 changed files with 208 additions and 0 deletions.
diff --git a/middleware/context.go b/middleware/context.go
@@ -567,6 +567,26 @@ func (c *Context) Respond(rw http.ResponseWriter, r *http.Request, produces []st
 	c.api.ServeErrorFor(route.Operation.ID)(rw, r, errors.New(http.StatusInternalServerError, "can't produce response"))
 }
 
+func (c *Context) APIHandlerSwaggerUI(builder Builder) http.Handler {
+	b := builder
+	if b == nil {
+		b = PassthroughBuilder
+	}
+
+	var title string
+	sp := c.spec.Spec()
+	if sp != nil && sp.Info != nil && sp.Info.Title != "" {
+		title = sp.Info.Title
+	}
+
+	swaggerUIOpts := SwaggerUIOpts{
+		BasePath: c.BasePath(),
+		Title:    title,
+	}
+
+	return Spec("", c.spec.Raw(), SwaggerUI(swaggerUIOpts, c.RoutesHandler(b)))
+}
+
 // APIHandler returns a handler to serve the API, this includes a swagger spec, router and the contract defined in the swagger spec
 func (c *Context) APIHandler(builder Builder) http.Handler {
 	b := builder

diff --git a/middleware/swaggerui.go b/middleware/swaggerui.go
@@ -0,0 +1,162 @@
+package middleware
+
+import (
+	"bytes"
+	"fmt"
+	"html/template"
+	"net/http"
+	"path"
+)
+
+// SwaggerUIOpts configures the Swaggerui middlewares
+type SwaggerUIOpts 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
+
+	// The three components needed to embed swagger-ui
+	SwaggerURL       string
+	SwaggerPresetURL string
+	SwaggerStylesURL string
+
+	Favicon32 string
+	Favicon16 string
+
+	// Title for the documentation site, default to: API documentation
+	Title string
+}
+
+// EnsureDefaults in case some options are missing
+func (r *SwaggerUIOpts) EnsureDefaults() {
+	if r.BasePath == "" {
+		r.BasePath = "/"
+	}
+	if r.Path == "" {
+		r.Path = "docs"
+	}
+	if r.SpecURL == "" {
+		r.SpecURL = "/swagger.json"
+	}
+	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
+	}
+	if r.Title == "" {
+		r.Title = "API documentation"
+	}
+}
+
+// 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(swaggeruiTemplate))
+
+	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 (
+	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      = `
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8">
+		<title>{{ .Title }}</title>
+
+    <link rel="stylesheet" type="text/css" href="{{ .SwaggerStylesURL }}" >
+    <link rel="icon" type="image/png" href="{{ .Favicon32 }}" sizes="32x32" />
+    <link rel="icon" type="image/png" href="{{ .Favicon16 }}" sizes="16x16" />
+    <style>
+      html
+      {
+        box-sizing: border-box;
+        overflow: -moz-scrollbars-vertical;
+        overflow-y: scroll;
+      }
+
+      *,
+      *:before,
+      *:after
+      {
+        box-sizing: inherit;
+      }
+
+      body
+      {
+        margin:0;
+        background: #fafafa;
+      }
+    </style>
+  </head>
+
+  <body>
+    <div id="swagger-ui"></div>
+
+    <script src="{{ .SwaggerURL }}"> </script>
+    <script src="{{ .SwaggerPresetURL }}"> </script>
+    <script>
+    window.onload = function() {
+      // Begin Swagger UI call region
+      const ui = SwaggerUIBundle({
+        url: '{{ .SpecURL }}',
+        dom_id: '#swagger-ui',
+        deepLinking: true,
+        presets: [
+          SwaggerUIBundle.presets.apis,
+          SwaggerUIStandalonePreset
+        ],
+        plugins: [
+          SwaggerUIBundle.plugins.DownloadUrl
+        ],
+        layout: "StandaloneLayout"
+      })
+      // End Swagger UI call region
+
+      window.ui = ui
+    }
+  </script>
+  </body>
+</html>
+`
+)
diff --git a/middleware/swaggerui_test.go b/middleware/swaggerui_test.go
@@ -0,0 +1,26 @@
+package middleware
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestSwaggerUIMiddleware(t *testing.T) {
+	redoc := SwaggerUI(SwaggerUIOpts{}, nil)
+
+	req, _ := http.NewRequest("GET", "/docs", nil)
+	recorder := httptest.NewRecorder()
+	redoc.ServeHTTP(recorder, req)
+	assert.Equal(t, 200, recorder.Code)
+	assert.Equal(t, "text/html; charset=utf-8", recorder.Header().Get("Content-Type"))
+	assert.Contains(t, recorder.Body.String(), "<title>API documentation</title>")
+	assert.Contains(t, recorder.Body.String(), "url: '\\/swagger.json',")
+	assert.Contains(t, recorder.Body.String(), swaggerLatest)
+	assert.Contains(t, recorder.Body.String(), swaggerPresetLatest)
+	assert.Contains(t, recorder.Body.String(), swaggerStylesLatest)
+	assert.Contains(t, recorder.Body.String(), swaggerFavicon16Latest)
+	assert.Contains(t, recorder.Body.String(), swaggerFavicon32Latest)
+}