dashboard: display subsystems in bug lists

To generate filtering URLs, use the ability of context.Context to carry
on variable values.

5 files changed, 59 insertions, 1 deletions

diff --git a/dashboard/app/handler.go b/dashboard/app/handler.go
index 2cb0d2739..7c6e9a23e 100644
--- a/dashboard/app/handler.go
+++ b/dashboard/app/handler.go
@@ -32,6 +32,7 @@ func handlerWrapper(fn contextHandler) http.Handler {
 func handleContext(fn contextHandler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		c := appengine.NewContext(r)
+		c = context.WithValue(c, currentURLKey, r.URL.RequestURI())
 		if err := fn(c, w, r); err != nil {
 			hdr := commonHeaderRaw(c, r)
 			data := &struct {
@@ -73,6 +74,16 @@ func handleContext(fn contextHandler) http.Handler {
 	})
 }
 
+const currentURLKey = "current_url"
+
+func getCurrentURL(c context.Context) string {
+	val, ok := c.Value(currentURLKey).(string)
+	if ok {
+		return val
+	}
+	return ""
+}
+
 type (
 	ErrClient   struct{ error }
 	ErrRedirect struct{ error }
diff --git a/dashboard/app/main.go b/dashboard/app/main.go
index 9d1340425..05eee1687 100644
--- a/dashboard/app/main.go
+++ b/dashboard/app/main.go
@@ -234,6 +234,12 @@ type uiBug struct {
 	MissingOn      []string
 	NumManagers    int
 	LastActivity   time.Time
+	Subsystems     []*uiBugSubsystem
+}
+
+type uiBugSubsystem struct {
+	Name string
+	Link string
 }
 
 type uiCrash struct {
@@ -1120,6 +1126,12 @@ func createUIBug(c context.Context, bug *Bug, state *ReportingState, managers []
 		NumManagers:    len(managers),
 		LastActivity:   bug.LastActivity,
 	}
+	for _, entry := range bug.Tags.Subsystems {
+		uiBug.Subsystems = append(uiBug.Subsystems, &uiBugSubsystem{
+			Name: entry.Name,
+			Link: html.AmendURL(getCurrentURL(c), "subsystem", entry.Name),
+		})
+	}
 	updateBugBadness(c, uiBug)
 	if len(bug.Commits) != 0 {
 		for i, com := range bug.Commits {
diff --git a/dashboard/app/templates.html b/dashboard/app/templates.html
index 12b51072a..01055dd5c 100644
--- a/dashboard/app/templates.html
+++ b/dashboard/app/templates.html
@@ -125,7 +125,12 @@ Use of this source code is governed by Apache 2 LICENSE that can be found in the
 	{{range $b := .Bugs}}
 		<tr>
 			{{if $.ShowNamespace}}<td>{{$b.Namespace}}</td>{{end}}
-			<td class="title"><a href="{{$b.Link}}">{{$b.Title}}</a></td>
+			<td class="title">
+				<a href="{{$b.Link}}">{{$b.Title}}</a>
+				{{- range $b.Subsystems}}
+					<span class="subsystem">{{link .Link .Name}}</span>
+				{{- end}}
+			</td>
 			<td class="stat">{{formatReproLevel $b.ReproLevel}}</td>
 			<td class="bisect_status">{{print $b.BisectCause}}</td>
 			<td class="bisect_status">{{print $b.BisectFix}}</td>
diff --git a/pkg/html/html.go b/pkg/html/html.go
index 8dc075bb6..c89c42fbb 100644
--- a/pkg/html/html.go
+++ b/pkg/html/html.go
@@ -6,6 +6,7 @@ package html
 import (
 	"fmt"
 	"html/template"
+	"net/url"
 	"reflect"
 	"strings"
 	texttemplate "text/template"
@@ -191,3 +192,17 @@ func dereferencePointer(v interface{}) interface{} {
 func commitLink(repo, commit string) string {
 	return vcs.CommitLink(repo, commit)
 }
+
+func AmendURL(baseURL, key, value string) string {
+	if baseURL == "" {
+		return ""
+	}
+	parsed, err := url.Parse(baseURL)
+	if err != nil {
+		return ""
+	}
+	values := parsed.Query()
+	values.Set(key, value)
+	parsed.RawQuery = values.Encode()
+	return parsed.String()
+}
diff --git a/pkg/html/pages/style.css b/pkg/html/pages/style.css
index d5ceef253..71a3efe71 100644
--- a/pkg/html/pages/style.css
+++ b/pkg/html/pages/style.css
@@ -194,6 +194,21 @@ table td, table th {
 	display: inline-block;
 }
 
+.list_table .subsystem {
+	background: white;
+	border: 1pt solid black;
+	display: inline-block;
+	padding-left: 2pt;
+	padding-right: 2pt;
+	margin-left: 4pt;
+	font-size: small;
+}
+
+.list_table .subsystem a {
+	text-decoration: none;
+	color: black;
+}
+
 .bad {
 	color: #f00;
 	font-weight: bold;