Add asset file upload form, plus related necessary refactors

srv/src/api/api.go

@@ -11,6 +11,7 @@ import (
 	"net/url"
 	"os"
 
+	"github.com/mediocregopher/blog.mediocregopher.com/srv/api/apiutil"
 	"github.com/mediocregopher/blog.mediocregopher.com/srv/cfg"
 	"github.com/mediocregopher/blog.mediocregopher.com/srv/chat"
 	"github.com/mediocregopher/blog.mediocregopher.com/srv/mailinglist"
@@ -158,9 +159,9 @@ func (a *api) handler() http.Handler {
 		return a.requirePowMiddleware(h)
 	}
 
-	postFormMiddleware := func(h http.Handler) http.Handler {
+	formMiddleware := func(h http.Handler) http.Handler {
 		h = checkCSRFMiddleware(h)
-		h = postOnlyMiddleware(h)
+		h = disallowGetMiddleware(h)
 		h = logReqMiddleware(h)
 		h = addResponseHeaders(map[string]string{
 			"Cache-Control": "no-store, max-age=0",
@@ -193,14 +194,17 @@ func (a *api) handler() http.Handler {
 			a.requirePowMiddleware,
 		)))
 
-		mux.Handle("/api/", http.StripPrefix("/api", postFormMiddleware(apiMux)))
+		mux.Handle("/api/", http.StripPrefix("/api", formMiddleware(apiMux)))
 	}
 
 	{
 		v2Mux := http.NewServeMux()
 		v2Mux.Handle("/follow.html", a.renderDumbHandler("follow.html"))
 		v2Mux.Handle("/posts/", a.renderPostHandler())
-		v2Mux.Handle("/assets", a.renderPostAssetsIndexHandler())
+		v2Mux.Handle("/assets", apiutil.MethodMux(map[string]http.Handler{
+			"GET":  a.renderPostAssetsIndexHandler(),
+			"POST": formMiddleware(a.uploadPostAssetHandler()),
+		}))
 		v2Mux.Handle("/assets/", a.servePostAssetHandler())
 		v2Mux.Handle("/", a.renderIndexHandler())
 

srv/src/api/apiutil/apiutil.go

@@ -11,6 +11,7 @@ import (
 	"fmt"
 	"net/http"
 	"strconv"
+	"strings"
 
 	"github.com/mediocregopher/mediocre-go-lib/v2/mlog"
 )
@@ -110,3 +111,23 @@ func RandStr(numBytes int) string {
 	}
 	return hex.EncodeToString(b)
 }
+
+// MethodMux will take the request method (GET, POST, etc...) and handle the
+// request using the corresponding Handler in the given map.
+//
+// If no Handler is defined for a method then a 405 Method Not Allowed error is
+// returned.
+func MethodMux(handlers map[string]http.Handler) http.Handler {
+
+	return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
+
+		handler, ok := handlers[strings.ToUpper(r.Method)]
+
+		if !ok {
+			http.Error(rw, "Method not allowed", http.StatusMethodNotAllowed)
+			return
+		}
+
+		handler.ServeHTTP(rw, r)
+	})
+}

srv/src/api/assets.go

@@ -111,3 +111,31 @@ func (a *api) servePostAssetHandler() http.Handler {
 
 	})
 }
+
+func (a *api) uploadPostAssetHandler() http.Handler {
+
+	renderIndex := a.renderPostAssetsIndexHandler()
+
+	return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
+
+		id := r.PostFormValue("id")
+		if id == "" {
+			apiutil.BadRequest(rw, r, errors.New("id is required"))
+			return
+		}
+
+		file, _, err := r.FormFile("file")
+		if err != nil {
+			apiutil.BadRequest(rw, r, fmt.Errorf("reading multipart file: %w", err))
+			return
+		}
+		defer file.Close()
+
+		if err := a.params.PostAssetStore.Set(id, file); err != nil {
+			apiutil.InternalServerError(rw, r, fmt.Errorf("storing file: %w", err))
+			return
+		}
+
+		renderIndex.ServeHTTP(rw, r)
+	})
+}

srv/src/api/csrf.go

@@ -10,6 +10,7 @@ import (
 const (
 	csrfTokenCookieName = "csrf_token"
 	csrfTokenHeaderName = "X-CSRF-Token"
+	csrfTokenFormName   = "csrfToken"
 )
 
 func setCSRFMiddleware(h http.Handler) http.Handler {
@@ -45,7 +46,7 @@ func checkCSRFMiddleware(h http.Handler) http.Handler {
 
 		givenCSRFTok := r.Header.Get(csrfTokenHeaderName)
 		if givenCSRFTok == "" {
-			givenCSRFTok = r.FormValue("csrfToken")
+			givenCSRFTok = r.FormValue(csrfTokenFormName)
 		}
 
 		if csrfTok == "" || givenCSRFTok != csrfTok {

srv/src/api/middleware.go

@@ -80,11 +80,11 @@ func logReqMiddleware(h http.Handler) http.Handler {
 	})
 }
 
-func postOnlyMiddleware(h http.Handler) http.Handler {
+func disallowGetMiddleware(h http.Handler) http.Handler {
 	return http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
 
-		// we allow websockets to not be POSTs because, well, they can't be
-		if r.Method == "POST" || r.Header.Get("Upgrade") == "websocket" {
+		// we allow websockets to be GETs because, well, they must be
+		if r.Method != "GET" || r.Header.Get("Upgrade") == "websocket" {
 			h.ServeHTTP(rw, r)
 			return
 		}

srv/src/api/render.go

@@ -51,6 +51,39 @@ func (a *api) mustParseTpl(name string) *template.Template {
 	return tpl
 }
 
+type tplData struct {
+	Payload   interface{}
+	CSRFToken string
+}
+
+func (t tplData) CSRFFormInput() template.HTML {
+	return template.HTML(fmt.Sprintf(
+		`<input type="hidden" name="%s" value="%s" />`,
+		csrfTokenFormName, t.CSRFToken,
+	))
+}
+
+// executeTemplate expects to be the final action in an http.Handler
+func executeTemplate(
+	rw http.ResponseWriter, r *http.Request,
+	tpl *template.Template, payload interface{},
+) {
+
+	csrfToken, _ := apiutil.GetCookie(r, csrfTokenCookieName, "")
+
+	tplData := tplData{
+		Payload:   payload,
+		CSRFToken: csrfToken,
+	}
+
+	if err := tpl.Execute(rw, tplData); err != nil {
+		apiutil.InternalServerError(
+			rw, r, fmt.Errorf("rendering template: %w", err),
+		)
+		return
+	}
+}
+
 func (a *api) renderIndexHandler() http.Handler {
 
 	tpl := a.mustParseTpl("index.html")
@@ -79,7 +112,7 @@ func (a *api) renderIndexHandler() http.Handler {
 			return
 		}
 
-		tplData := struct {
+		tplPayload := struct {
 			Posts              []post.StoredPost
 			PrevPage, NextPage int
 		}{
@@ -89,19 +122,14 @@ func (a *api) renderIndexHandler() http.Handler {
 		}
 
 		if page > 0 {
-			tplData.PrevPage = page - 1
+			tplPayload.PrevPage = page - 1
 		}
 
 		if hasMore {
-			tplData.NextPage = page + 1
+			tplPayload.NextPage = page + 1
 		}
 
-		if err := tpl.Execute(rw, tplData); err != nil {
-			apiutil.InternalServerError(
-				rw, r, fmt.Errorf("rendering index: %w", err),
-			)
-			return
-		}
+		executeTemplate(rw, r, tpl, tplPayload)
 	})
 }
 
@@ -133,7 +161,7 @@ func (a *api) renderPostHandler() http.Handler {
 
 		renderedBody := markdown.ToHTML([]byte(storedPost.Body), parser, htmlRenderer)
 
-		tplData := struct {
+		tplPayload := struct {
 			post.StoredPost
 			SeriesPrevious, SeriesNext *post.StoredPost
 			Body                       template.HTML
@@ -165,21 +193,16 @@ func (a *api) renderPostHandler() http.Handler {
 				}
 
 				if !foundThis {
-					tplData.SeriesPrevious = &seriesPost
+					tplPayload.SeriesPrevious = &seriesPost
 					continue
 				}
 
-				tplData.SeriesNext = &seriesPost
+				tplPayload.SeriesNext = &seriesPost
 				break
 			}
 		}
 
-		if err := tpl.Execute(rw, tplData); err != nil {
-			apiutil.InternalServerError(
-				rw, r, fmt.Errorf("rendering post with id %q: %w", id, err),
-			)
-			return
-		}
+		executeTemplate(rw, r, tpl, tplPayload)
 	})
 }
 
@@ -212,17 +235,12 @@ func (a *api) renderPostAssetsIndexHandler() http.Handler {
 			return
 		}
 
-		tplData := struct {
+		tplPayload := struct {
 			IDs []string
 		}{
 			IDs: ids,
 		}
 
-		if err := tpl.Execute(rw, tplData); err != nil {
-			apiutil.InternalServerError(
-				rw, r, fmt.Errorf("rendering: %w", err),
-			)
-			return
-		}
+		executeTemplate(rw, r, tpl, tplPayload)
 	})
 }

srv/src/api/tpl/admin-assets.html

@@ -1,8 +1,32 @@
 {{ define "body" }}
 
+<h2>Upload Asset</h2>
+
+<p>
+  If the given ID is the same as an existing asset's ID, then that asset will be
+  overwritten.
+</p>
+
+<form action={{ BlogURL "assets" }} method="POST" enctype="multipart/form-data">
+  {{ .CSRFFormInput }}
+  <div class="row">
+    <div class="four columns">
+      <input type="text" placeholder="Unique ID" name="id" />
+    </div>
+    <div class="four columns">
+      <input type="file" name="file" /><br/>
+    </div>
+    <div class="four columns">
+      <input type="submit" value="Upload" />
+    </div>
+  </div>
+</form>
+
+<h2>Existing Assets</h2>
+
 <table>
 
-  {{ range .IDs }}
+  {{ range .Payload.IDs }}
     <tr>
       <td><a href="{{ AssetURL . }}" target="_blank">{{ . }}</a></td>
       <td>

srv/src/api/tpl/index.html

@@ -2,7 +2,7 @@
 
   <ul id="posts-list">
 
-    {{ range .Posts }}
+    {{ range .Payload.Posts }}
     <li>
       <h2>
         <a href="posts/{{ .HTTPPath }}">{{ .Title }}</a>
@@ -17,15 +17,15 @@
 
   </ul>
 
-  {{ if or (ge .PrevPage 0) (ge .NextPage 0) }}
+  {{ if or (ge .Payload.PrevPage 0) (ge .Payload.NextPage 0) }}
     <div id="page-turner">
 
-    {{ if ge .PrevPage 0 }}
-      <a style="float: left;" href="?p={{ .PrevPage}}">Newer</a>
+    {{ if ge .Payload.PrevPage 0 }}
+      <a style="float: left;" href="?p={{ .Payload.PrevPage}}">Newer</a>
     {{ end }}
 
-    {{ if ge .NextPage 0 }}
-      <a style="float:right;" href="?p={{ .NextPage}}">Older</a>
+    {{ if ge .Payload.NextPage 0 }}
+      <a style="float:right;" href="?p={{ .Payload.NextPage}}">Older</a>
     {{ end }}
 
     </div>

srv/src/api/tpl/post.html

@@ -2,43 +2,43 @@
 
 <header id="post-header">
   <h1 id="post-headline">
-    {{ .Title }}
+    {{ .Payload.Title }}
   </h1>
   <div class="light">
-    {{ .PublishedAt.Format "2006-01-02" }}
+    {{ .Payload.PublishedAt.Format "2006-01-02" }}
     &nbsp;•&nbsp;
-    {{ if not .LastUpdatedAt.IsZero }}
-    (Updated {{ .LastUpdatedAt.Format "2006-01-02" }})
+    {{ if not .Payload.LastUpdatedAt.IsZero }}
+    (Updated {{ .Payload.LastUpdatedAt.Format "2006-01-02" }})
     &nbsp;•&nbsp;
     {{ end }}
-    <em>{{ .Description }}</em>
+    <em>{{ .Payload.Description }}</em>
   </div>
 </header>
 
-{{ if (or .SeriesPrevious .SeriesNext) }}
+{{ if (or .Payload.SeriesPrevious .Payload.SeriesNext) }}
 <p class="light"><em>
   This post is part of a series:<br/>
-  {{ if .SeriesPrevious }}
-  Previously: <a href="{{ .SeriesPrevious.HTTPPath }}">{{ .SeriesPrevious.Title }}</a></br>
+  {{ if .Payload.SeriesPrevious }}
+  Previously: <a href="{{ .Payload.SeriesPrevious.HTTPPath }}">{{ .Payload.SeriesPrevious.Title }}</a></br>
   {{ end }}
-  {{ if .SeriesNext }}
-  Next: <a href="{{ .SeriesNext.HTTPPath }}">{{ .SeriesNext.Title }}</a></br>
+  {{ if .Payload.SeriesNext }}
+  Next: <a href="{{ .Payload.SeriesNext.HTTPPath }}">{{ .Payload.SeriesNext.Title }}</a></br>
   {{ end }}
 </em></p>
 {{ end }}
 
 <div id="post-content">
-  {{ .Body }}
+  {{ .Payload.Body }}
 </div>
 
-{{ if (or .SeriesPrevious .SeriesNext) }}
+{{ if (or .Payload.SeriesPrevious .Payload.SeriesNext) }}
 <p class="light"><em>
   If you liked this post, consider checking out other posts in the series:<br/>
-  {{ if .SeriesPrevious }}
-  Previously: <a href="{{ .SeriesPrevious.HTTPPath }}">{{ .SeriesPrevious.Title }}</a></br>
+  {{ if .Payload.SeriesPrevious }}
+  Previously: <a href="{{ .Payload.SeriesPrevious.HTTPPath }}">{{ .Payload.SeriesPrevious.Title }}</a></br>
   {{ end }}
-  {{ if .SeriesNext }}
-  Next: <a href="{{ .SeriesNext.HTTPPath }}">{{ .SeriesNext.Title }}</a></br>
+  {{ if .Payload.SeriesNext }}
+  Next: <a href="{{ .Payload.SeriesNext.HTTPPath }}">{{ .Payload.SeriesNext.Title }}</a></br>
   {{ end }}
 </em></p>
 {{ end }}