Make HTTP middleware easier to use

appengine/cmd/cron/ui/invocation.go

Index: appengine/cmd/cron/ui/invocation.go
diff --git a/appengine/cmd/cron/ui/invocation.go b/appengine/cmd/cron/ui/invocation.go
index ff9fe101df40ec2018f08d05325014f74bc406e5..14b763fb2fd560a11e49246bb6a0f0156d4e8be8 100644
--- a/appengine/cmd/cron/ui/invocation.go
+++ b/appengine/cmd/cron/ui/invocation.go
@@ -2,72 +2,70 @@
 // Use of this source code is governed under the Apache License, Version 2.0
 // that can be found in the LICENSE file.
 
 package ui
 
 import (
 	"fmt"
 	"net/http"
 	"strconv"
 
-	"github.com/julienschmidt/httprouter"
-	"golang.org/x/net/context"
-
 	"github.com/luci/luci-go/common/clock"
 	"github.com/luci/luci-go/server/auth"
+	"github.com/luci/luci-go/server/router"
 	"github.com/luci/luci-go/server/templates"
 )
 
-func invocationPage(c context.Context, w http.ResponseWriter, r *http.Request, p httprouter.Params) {
-	projectID := p.ByName("ProjectID")
-	jobID := p.ByName("JobID")
-	invID, err := strconv.ParseInt(p.ByName("InvID"), 10, 64)
+func invocationPage(c *router.Context) {
+	projectID := c.Params.ByName("ProjectID")
+	jobID := c.Params.ByName("JobID")
+	invID, err := strconv.ParseInt(c.Params.ByName("InvID"), 10, 64)
 	if err != nil {
-		http.Error(w, "No such invocation", http.StatusNotFound)
+		http.Error(c.Writer, "No such invocation", http.StatusNotFound)
 		return
 	}
 
-	inv, err := config(c).Engine.GetInvocation(c, projectID+"/"+jobID, invID)
+	inv, err := config(c.Context).Engine.GetInvocation(c.Context, projectID+"/"+jobID, invID)
 	if err != nil {
 		panic(err)
 	}
 	if inv == nil {
-		http.Error(w, "No such invocation", http.StatusNotFound)
+		http.Error(c.Writer, "No such invocation", http.StatusNotFound)
 		return
 	}
 
-	now := clock.Now(c).UTC()
-	templates.MustRender(c, w, "pages/invocation.html", map[string]interface{}{
+	now := clock.Now(c.Context).UTC()
+	templates.MustRender(c.Context, c.Writer, "pages/invocation.html", map[string]interface{}{
 		"ProjectID": projectID,
 		"JobID":     jobID,
 		"Inv":       makeInvocation(projectID, jobID, inv, now),
 	})
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // Actions.
 
-func abortInvocationAction(c context.Context, w http.ResponseWriter, r *http.Request, p httprouter.Params) {
-	handleInvAction(c, w, r, p, func(jobID string, invID int64) error {
-		who := auth.CurrentIdentity(c)
-		return config(c).Engine.AbortInvocation(c, jobID, invID, who)
+func abortInvocationAction(c *router.Context) {
+	handleInvAction(c, func(jobID string, invID int64) error {
+		who := auth.CurrentIdentity(c.Context)
+		return config(c.Context).Engine.AbortInvocation(c.Context, jobID, invID, who)
 	})
 }
 
-func handleInvAction(c context.Context, w http.ResponseWriter, r *http.Request, p httprouter.Params, cb func(string, int64) error) {
-	projectID := p.ByName("ProjectID")
-	jobID := p.ByName("JobID")
-	invID := p.ByName("InvID")
-	if !isJobOwner(c, projectID, jobID) {
-		http.Error(w, "Forbidden", 403)
+func handleInvAction(c *router.Context, cb func(string, int64) error) {
+	projectID := c.Params.ByName("ProjectID")
+	jobID := c.Params.ByName("JobID")
+	invID := c.Params.ByName("InvID")
+	if !isJobOwner(c.Context, projectID, jobID) {
+		http.Error(c.Writer, "Forbidden", 403)
 		return
 	}
 	invIDAsInt, err := strconv.ParseInt(invID, 10, 64)
 	if err != nil {
-		http.Error(w, "Bad invocation ID", 400)
+		http.Error(c.Writer, "Bad invocation ID", 400)
 		return
 	}
 	if err := cb(projectID+"/"+jobID, invIDAsInt); err != nil {
 		panic(err)
 	}
-	http.Redirect(w, r, fmt.Sprintf("/jobs/%s/%s/%s", projectID, jobID, invID), http.StatusFound)
+	http.Redirect(c.Writer, c.Request, fmt.Sprintf("/jobs/%s/%s/%s", projectID, jobID, invID), http.StatusFound)
 }