Add RSS/Atom feed support for user actions (#16002)

Return rss/atom feed for user based on rss url suffix or Content-Type header.

routers/web/feed/profile.go

@@ -0,0 +1,98 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package feed
+
+import (
+	"net/http"
+	"time"
+
+	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/modules/context"
+
+	"github.com/gorilla/feeds"
+)
+
+// RetrieveFeeds loads feeds for the specified user
+func RetrieveFeeds(ctx *context.Context, options models.GetFeedsOptions) []*models.Action {
+	actions, err := models.GetFeeds(options)
+	if err != nil {
+		ctx.ServerError("GetFeeds", err)
+		return nil
+	}
+
+	userCache := map[int64]*models.User{options.RequestedUser.ID: options.RequestedUser}
+	if ctx.User != nil {
+		userCache[ctx.User.ID] = ctx.User
+	}
+	for _, act := range actions {
+		if act.ActUser != nil {
+			userCache[act.ActUserID] = act.ActUser
+		}
+	}
+
+	for _, act := range actions {
+		repoOwner, ok := userCache[act.Repo.OwnerID]
+		if !ok {
+			repoOwner, err = models.GetUserByID(act.Repo.OwnerID)
+			if err != nil {
+				if models.IsErrUserNotExist(err) {
+					continue
+				}
+				ctx.ServerError("GetUserByID", err)
+				return nil
+			}
+			userCache[repoOwner.ID] = repoOwner
+		}
+		act.Repo.Owner = repoOwner
+	}
+	return actions
+}
+
+// ShowUserFeed show user activity as RSS / Atom feed
+func ShowUserFeed(ctx *context.Context, ctxUser *models.User, formatType string) {
+	actions := RetrieveFeeds(ctx, models.GetFeedsOptions{
+		RequestedUser:   ctxUser,
+		Actor:           ctx.User,
+		IncludePrivate:  false,
+		OnlyPerformedBy: true,
+		IncludeDeleted:  false,
+		Date:            ctx.FormString("date"),
+	})
+	if ctx.Written() {
+		return
+	}
+
+	feed := &feeds.Feed{
+		Title:       ctx.Tr("home.feed_of", ctxUser.DisplayName()),
+		Link:        &feeds.Link{Href: ctxUser.HTMLURL()},
+		Description: ctxUser.Description,
+		Created:     time.Now(),
+	}
+
+	var err error
+	feed.Items, err = feedActionsToFeedItems(ctx, actions)
+	if err != nil {
+		ctx.ServerError("convert feed", err)
+		return
+	}
+
+	writeFeed(ctx, feed, formatType)
+}
+
+// writeFeed write a feeds.Feed as atom or rss to ctx.Resp
+func writeFeed(ctx *context.Context, feed *feeds.Feed, formatType string) {
+	ctx.Resp.WriteHeader(http.StatusOK)
+	if formatType == "atom" {
+		ctx.Resp.Header().Set("Content-Type", "application/atom+xml;charset=utf-8")
+		if err := feed.WriteAtom(ctx.Resp); err != nil {
+			ctx.ServerError("Render Atom failed", err)
+		}
+	} else {
+		ctx.Resp.Header().Set("Content-Type", "application/rss+xml;charset=utf-8")
+		if err := feed.WriteRss(ctx.Resp); err != nil {
+			ctx.ServerError("Render RSS failed", err)
+		}
+	}
+}