PWA: First implementation of offline mode

client/model.go

@@ -46,6 +46,7 @@ type User struct {
 	BlockFilterEntryRules  string     `json:"block_filter_entry_rules"`
 	KeepFilterEntryRules   string     `json:"keep_filter_entry_rules"`
 	ExternalFontHosts      string     `json:"external_font_hosts"`
+	CacheForOffline        bool       `json:"cache_for_offline"`
 }
 
 func (u User) String() string {

internal/database/migrations.go

@@ -970,27 +970,28 @@
 		return err
 	},
 	func(tx *sql.Tx, _ string) (err error) {
+<<<<<<< HEAD
 		sql := `
 			ALTER TABLE integrations ADD COLUMN discord_enabled bool default 'f';
 			ALTER TABLE integrations ADD COLUMN discord_webhook_link text default '';
 		`
 		_, err = tx.Exec(sql)
 		return err
 	},
 	func(tx *sql.Tx, _ string) (err error) {
 		sql := `ALTER TABLE integrations ADD COLUMN ntfy_internal_links bool default 'f';`
 		_, err = tx.Exec(sql)
 		return err
 	},
 	func(tx *sql.Tx, _ string) (err error) {
 		sql := `
 			ALTER TABLE integrations ADD COLUMN slack_enabled bool default 'f';
 			ALTER TABLE integrations ADD COLUMN slack_webhook_link text default '';
 		`
 		_, err = tx.Exec(sql)
 		return err
 	},
 	func(tx *sql.Tx, _ string) (err error) {
 		_, err = tx.Exec(`ALTER TABLE feeds ADD COLUMN webhook_url text default '';`)
 		return err
 	},
@@ -1015,4 +1016,9 @@
 		_, err = tx.Exec(sql)
 		return err
 	},
+	func(tx *sql.Tx, _ string) (err error) {
+		sql := `ALTER TABLE users ADD COLUMN cache_for_offline boolean default 'f'`
+		_, err = tx.Exec(sql)
+		return err
+	},
 }

internal/http/request/context.go

@@ -140,6 +140,11 @@ func LastForceRefresh(r *http.Request) int64 {
 	return timestamp
 }
 
+// Determine if the request is from a service worker.
+func IsServiceWorker(r *http.Request) bool {
+	return r.Header.Get("Client-Type") == "service-worker"
+}
+
 // ClientIP returns the client IP address stored in the context.
 func ClientIP(r *http.Request) string {
 	return getContextStringValue(r, ClientIPContextKey)

internal/http/response/builder.go

@@ -100,7 +100,7 @@ func (b *Builder) Write() {
 func (b *Builder) writeHeaders() {
 	b.headers["X-Content-Type-Options"] = "nosniff"
 	b.headers["X-Frame-Options"] = "DENY"
-	b.headers["Referrer-Policy"] = "no-referrer"
+	b.headers["Referrer-Policy"] = "strict-origin"
 
 	for key, value := range b.headers {
 		b.w.Header().Set(key, value)

internal/model/user.go

@@ -41,6 +41,7 @@ type User struct {
 	MediaPlaybackRate               float64    `json:"media_playback_rate"`
 	BlockFilterEntryRules           string     `json:"block_filter_entry_rules"`
 	KeepFilterEntryRules            string     `json:"keep_filter_entry_rules"`
+	CacheForOffline                 bool       `json:"cache_for_offline"`
 }
 
 // UserCreationRequest represents the request to create a user.
@@ -82,6 +83,7 @@ type UserModificationRequest struct {
 	MediaPlaybackRate               *float64 `json:"media_playback_rate"`
 	BlockFilterEntryRules           *string  `json:"block_filter_entry_rules"`
 	KeepFilterEntryRules            *string  `json:"keep_filter_entry_rules"`
+	CacheForOffline                 *bool    `json:"cache_for_offline"`
 }
 
 // Patch updates the User object with the modification request.
@@ -197,6 +199,9 @@ func (u *UserModificationRequest) Patch(user *User) {
 	if u.KeepFilterEntryRules != nil {
 		user.KeepFilterEntryRules = *u.KeepFilterEntryRules
 	}
+	if u.CacheForOffline != nil {
+		user.CacheForOffline = *u.CacheForOffline
+	}
 }
 
 // UseTimezone converts last login date to the given timezone.

internal/reader/sanitizer/sanitizer.go

@@ -241,7 +241,7 @@ func sanitizeAttributes(baseURL, tagName string, attributes []html.Attribute) ([
 func getExtraAttributes(tagName string) ([]string, []string) {
 	switch tagName {
 	case "a":
-		return []string{"rel", "target", "referrerpolicy"}, []string{`rel="noopener noreferrer"`, `target="_blank"`, `referrerpolicy="no-referrer"`}
+		return []string{"rel", "target", "referrerpolicy"}, []string{`rel="noopener noreferrer"`, `target="_blank"`, `referrerpolicy="strict-origin"`}
 	case "video", "audio":
 		return []string{"controls"}, []string{"controls"}
 	case "iframe":

internal/storage/user.go

@@ -96,7 +96,8 @@ func (s *Storage) CreateUser(userCreationRequest *model.UserCreationRequest) (*m
 			mark_read_on_view,
 			media_playback_rate,
 			block_filter_entry_rules,
-			keep_filter_entry_rules
+			keep_filter_entry_rules,
+			cache_for_offline
 	`
 
 	tx, err := s.db.Begin()
@@ -140,6 +141,7 @@ func (s *Storage) CreateUser(userCreationRequest *model.UserCreationRequest) (*m
 		&user.MediaPlaybackRate,
 		&user.BlockFilterEntryRules,
 		&user.KeepFilterEntryRules,
+		&user.CacheForOffline,
 	)
 	if err != nil {
 		tx.Rollback()
@@ -204,9 +206,10 @@ func (s *Storage) UpdateUser(user *model.User) error {
 				mark_read_on_media_player_completion=$25,
 				media_playback_rate=$26,
 				block_filter_entry_rules=$27,
-				keep_filter_entry_rules=$28
+				keep_filter_entry_rules=$28,
+				cache_for_offline=$29
 			WHERE
-				id=$29
+				id=$30
 		`
 
 		_, err = s.db.Exec(
@@ -239,6 +242,7 @@ func (s *Storage) UpdateUser(user *model.User) error {
 			user.MediaPlaybackRate,
 			user.BlockFilterEntryRules,
 			user.KeepFilterEntryRules,
+			user.CacheForOffline,
 			user.ID,
 		)
 		if err != nil {
@@ -273,9 +277,10 @@ func (s *Storage) UpdateUser(user *model.User) error {
 				mark_read_on_media_player_completion=$24,
 				media_playback_rate=$25,
 				block_filter_entry_rules=$26,
-				keep_filter_entry_rules=$27
+				keep_filter_entry_rules=$27,
+				cache_for_offline=$28
 			WHERE
-				id=$28
+				id=$29
 		`
 
 		_, err := s.db.Exec(
@@ -307,6 +312,7 @@ func (s *Storage) UpdateUser(user *model.User) error {
 			user.MediaPlaybackRate,
 			user.BlockFilterEntryRules,
 			user.KeepFilterEntryRules,
+			user.CacheForOffline,
 			user.ID,
 		)
 
@@ -360,7 +366,8 @@ func (s *Storage) UserByID(userID int64) (*model.User, error) {
 			mark_read_on_media_player_completion,
 			media_playback_rate,
 			block_filter_entry_rules,
-			keep_filter_entry_rules
+			keep_filter_entry_rules,
+			cache_for_offline
 		FROM
 			users
 		WHERE
@@ -401,7 +408,8 @@ func (s *Storage) UserByUsername(username string) (*model.User, error) {
 			mark_read_on_media_player_completion,
 			media_playback_rate,
 			block_filter_entry_rules,
-			keep_filter_entry_rules
+			keep_filter_entry_rules,
+			cache_for_offline
 		FROM
 			users
 		WHERE
@@ -442,7 +450,8 @@ func (s *Storage) UserByField(field, value string) (*model.User, error) {
 			mark_read_on_media_player_completion,
 			media_playback_rate,
 			block_filter_entry_rules,
-			keep_filter_entry_rules
+			keep_filter_entry_rules,
+			cache_for_offline
 		FROM
 			users
 		WHERE
@@ -490,7 +499,8 @@ func (s *Storage) UserByAPIKey(token string) (*model.User, error) {
 			u.mark_read_on_media_player_completion,
 			media_playback_rate,
 			u.block_filter_entry_rules,
-			u.keep_filter_entry_rules
+			u.keep_filter_entry_rules,
+			u.cache_for_offline
 		FROM
 			users u
 		LEFT JOIN
@@ -533,6 +543,7 @@ func (s *Storage) fetchUser(query string, args ...interface{}) (*model.User, err
 		&user.MediaPlaybackRate,
 		&user.BlockFilterEntryRules,
 		&user.KeepFilterEntryRules,
+		&user.CacheForOffline,
 	)
 
 	if err == sql.ErrNoRows {
@@ -646,7 +657,9 @@ func (s *Storage) Users() (model.Users, error) {
 			mark_read_on_media_player_completion,
 			media_playback_rate,
 			block_filter_entry_rules,
-			keep_filter_entry_rules
+			keep_filter_entry_rules,
+			media_playback_rate,
+			cache_for_offline
 		FROM
 			users
 		ORDER BY username ASC
@@ -690,6 +703,7 @@ func (s *Storage) Users() (model.Users, error) {
 			&user.MediaPlaybackRate,
 			&user.BlockFilterEntryRules,
 			&user.KeepFilterEntryRules,
+			&user.CacheForOffline,
 		)
 
 		if err != nil {

internal/template/templates/common/layout.html

@@ -132,6 +132,7 @@
     {{ if .flashErrorMessage }}
         <div role="alert" class="flash-error-message alert alert-error">{{ .flashErrorMessage }}</div>
     {{ end }}
+		<div role="alert" aria-live="assertive" aria-atomic="true" class="flash-message alert alert-warning offline-hidden">{{ t "page.cache.warning" }}</div>
 
     {{template "page_header" .}}
 

internal/template/templates/views/entry.html

@@ -4,7 +4,7 @@
 <section class="entry" data-id="{{ .entry.ID }}" aria-labelledby="page-header-title">
     <header class="entry-header">
         <h1 id="page-header-title" dir="auto">
-            <a href="{{ .entry.URL | safeURL }}" target="_blank" rel="noopener noreferrer" referrerpolicy="no-referrer">{{ .entry.Title }}</a>
+            <a href="{{ .entry.URL | safeURL }}" target="_blank" rel="noopener noreferrer" referrerpolicy="strict-origin">{{ .entry.Title }}</a>
         </h1>
         {{ if .user }}
         <div class="entry-actions">
@@ -79,7 +79,7 @@ <h1 id="page-header-title" dir="auto">
                         class="page-link"
                         target="_blank"
                         rel="noopener noreferrer"
-                        referrerpolicy="no-referrer"
+                        referrerpolicy="strict-origin"
                         data-original-link="{{ .user.MarkReadOnView }}">{{ icon "external-link" }}<span class="icon-label">{{ t "entry.external_link.label" }}</span></a>
                 </li>
                 <li>
@@ -98,7 +98,7 @@ <h1 id="page-header-title" dir="auto">
                         title="{{ t "entry.comments.title" }}"
                         target="_blank"
                         rel="noopener noreferrer"
-                        referrerpolicy="no-referrer"
+                        referrerpolicy="strict-origin"
                         data-comments-link="true"
                         >{{ icon "comment" }}<span class="icon-label">{{ t "entry.comments.label" }}</span></a>
                 </li>
@@ -232,7 +232,7 @@ <h1 id="page-header-title" dir="auto">
         {{ end }}
 
         <div class="entry-enclosure-download">
-            <a href="{{ .URL | safeURL }}" title="{{ t "action.download" }}{{ if gt .Size 0 }} - {{ formatFileSize .Size }}{{ end }}" target="_blank" rel="noopener noreferrer" referrerpolicy="no-referrer">{{ .URL | safeURL  }}</a>
+            <a href="{{ .URL | safeURL }}" title="{{ t "action.download" }}{{ if gt .Size 0 }} - {{ formatFileSize .Size }}{{ end }}" target="_blank" rel="noopener noreferrer" referrerpolicy="strict-origin">{{ .URL | safeURL  }}</a>
             <small>{{ if gt .Size 0 }} - <strong>{{ formatFileSize .Size }}</strong>{{ end }}</small>
         </div>
     </div>

internal/ui/entry_unread.go

@@ -66,7 +66,7 @@ func (h *handler) showUnreadEntryPage(w http.ResponseWriter, r *http.Request) {
 		prevEntryRoute = route.Path(h.router, "unreadEntry", "entryID", prevEntry.ID)
 	}
 
-	if entry.ShouldMarkAsReadOnView(user) {
+	if entry.ShouldMarkAsReadOnView(user) && !request.IsServiceWorker(r) {
 		entry.Status = model.EntryStatusRead
 	}
 
@@ -90,6 +90,7 @@ func (h *handler) showUnreadEntryPage(w http.ResponseWriter, r *http.Request) {
 	view.Set("user", user)
 	view.Set("hasSaveEntry", h.store.HasSaveEntry(user.ID))
 	view.Set("countErrorFeeds", h.store.CountUserFeedsWithErrors(user.ID))
+	view.Set("useCachedVersion", r.Header.Get("X-Cache-Hit") != "")
 
 	// Fetching the counter here avoid to be off by one.
 	view.Set("countUnread", h.store.CountUnreadEntries(user.ID))

internal/ui/form/settings.go

@@ -52,6 +52,7 @@ type SettingsForm struct {
 	MediaPlaybackRate     float64
 	BlockFilterEntryRules string
 	KeepFilterEntryRules  string
+	CacheForOffline       bool
 }
 
 // MarkAsReadBehavior returns the MarkReadBehavior from the given MarkReadOnView and MarkReadOnMediaPlayerCompletion values.
@@ -119,6 +120,8 @@ func (s *SettingsForm) Merge(user *model.User) *model.User {
 	user.MarkReadOnView = MarkReadOnView
 	user.MarkReadOnMediaPlayerCompletion = MarkReadOnMediaPlayerCompletion
 
+	user.CacheForOffline = s.CacheForOffline
+
 	if s.Password != "" {
 		user.Password = s.Password
 	}
@@ -205,5 +208,6 @@ func NewSettingsForm(r *http.Request) *SettingsForm {
 		MediaPlaybackRate:      mediaPlaybackRate,
 		BlockFilterEntryRules:  r.FormValue("block_filter_entry_rules"),
 		KeepFilterEntryRules:   r.FormValue("keep_filter_entry_rules"),
+		CacheForOffline:        r.FormValue("cache_for_offline") == "1",
 	}
 }

internal/ui/settings_show.go

@@ -46,6 +46,7 @@ func (h *handler) showSettingsPage(w http.ResponseWriter, r *http.Request) {
 		MediaPlaybackRate:      user.MediaPlaybackRate,
 		BlockFilterEntryRules:  user.BlockFilterEntryRules,
 		KeepFilterEntryRules:   user.KeepFilterEntryRules,
+		CacheForOffline:        user.CacheForOffline,
 	}
 
 	timezones, err := h.store.Timezones()