Support filtering blog posts by language

Ref T805

collections.go

@@ -28,6 +28,7 @@ import (
 	"github.com/writeas/web-core/activitystreams"
 	"github.com/writeas/web-core/auth"
 	"github.com/writeas/web-core/bots"
+	"github.com/writeas/web-core/i18n"
 	"github.com/writeas/web-core/log"
 	waposts "github.com/writeas/web-core/posts"
 	"github.com/writefreely/writefreely/author"
@@ -366,6 +367,16 @@ func (c CollectionPage) DisplayMonetization() string {
 	return displayMonetization(c.Monetization, c.Alias)
 }
 
+func (c *DisplayCollection) Direction() string {
+	if c.Language == "" {
+		return "auto"
+	}
+	if i18n.LangIsRTL(c.Language) {
+		return "rtl"
+	}
+	return "ltr"
+}
+
 func newCollection(app *App, w http.ResponseWriter, r *http.Request) error {
 	reqJSON := IsJSON(r)
 	alias := r.FormValue("alias")
@@ -991,6 +1002,92 @@ func handleViewCollectionTag(app *App, w http.ResponseWriter, r *http.Request) e
 	return nil
 }
 
+func handleViewCollectionLang(app *App, w http.ResponseWriter, r *http.Request) error {
+	vars := mux.Vars(r)
+	lang := vars["lang"]
+
+	cr := &collectionReq{}
+	err := processCollectionRequest(cr, vars, w, r)
+	if err != nil {
+		return err
+	}
+
+	u, err := checkUserForCollection(app, cr, r, false)
+	if err != nil {
+		return err
+	}
+
+	page := getCollectionPage(vars)
+
+	c, err := processCollectionPermissions(app, cr, u, w, r)
+	if c == nil || err != nil {
+		return err
+	}
+
+	coll := newDisplayCollection(c, cr, page)
+	coll.Language = lang
+
+	coll.Posts, _ = app.db.GetLangPosts(app.cfg, c, lang, page, cr.isCollOwner)
+	if err != nil {
+		return ErrCollectionPageNotFound
+	}
+
+	// Serve collection
+	displayPage := struct {
+		CollectionPage
+		Tag string
+	}{
+		CollectionPage: CollectionPage{
+			DisplayCollection: coll,
+			StaticPage:        pageForReq(app, r),
+			IsCustomDomain:    cr.isCustomDomain,
+		},
+		Tag: lang,
+	}
+	var owner *User
+	if u != nil {
+		displayPage.Username = u.Username
+		displayPage.IsOwner = u.ID == coll.OwnerID
+		if displayPage.IsOwner {
+			// Add in needed information for users viewing their own collection
+			owner = u
+			displayPage.CanPin = true
+
+			pubColls, err := app.db.GetPublishableCollections(owner, app.cfg.App.Host)
+			if err != nil {
+				log.Error("unable to fetch collections: %v", err)
+			}
+			displayPage.Collections = pubColls
+		}
+	}
+	isOwner := owner != nil
+	if !isOwner {
+		// Current user doesn't own collection; retrieve owner information
+		owner, err = app.db.GetUserByID(coll.OwnerID)
+		if err != nil {
+			// Log the error and just continue
+			log.Error("Error getting user for collection: %v", err)
+		}
+		if owner.IsSilenced() {
+			return ErrCollectionNotFound
+		}
+	}
+	displayPage.Silenced = owner != nil && owner.IsSilenced()
+	displayPage.Owner = owner
+	coll.Owner = displayPage.Owner
+	// Add more data
+	// TODO: fix this mess of collections inside collections
+	displayPage.PinnedPosts, _ = app.db.GetPinnedPosts(coll.CollectionObj, isOwner)
+	displayPage.Monetization = app.db.GetCollectionAttribute(coll.ID, "monetization_pointer")
+
+	err = templates["collection"].ExecuteTemplate(w, "collection", displayPage)
+	if err != nil {
+		log.Error("Unable to render collection lang page: %v", err)
+	}
+
+	return nil
+}
+
 func handleCollectionPostRedirect(app *App, w http.ResponseWriter, r *http.Request) error {
 	vars := mux.Vars(r)
 	slug := vars["slug"]

database.go

@@ -1260,6 +1260,61 @@ func (db *datastore) GetPostsTagged(cfg *config.Config, c *Collection, tag strin
 	return &posts, nil
 }
 
+func (db *datastore) GetLangPosts(cfg *config.Config, c *Collection, lang string, page int, includeFuture bool) (*[]PublicPost, error) {
+	collID := c.ID
+
+	cf := c.NewFormat()
+	order := "DESC"
+	if cf.Ascending() {
+		order = "ASC"
+	}
+
+	pagePosts := cf.PostsPerPage()
+	start := page*pagePosts - pagePosts
+	if page == 0 {
+		start = 0
+		pagePosts = 1000
+	}
+
+	limitStr := ""
+	if page > 0 {
+		limitStr = fmt.Sprintf(" LIMIT %d, %d", start, pagePosts)
+	}
+	timeCondition := ""
+	if !includeFuture {
+		timeCondition = "AND created <= " + db.now()
+	}
+
+	rows, err := db.Query("SELECT "+postCols+" FROM posts WHERE collection_id = ? AND language = ? "+timeCondition+" ORDER BY created "+order+limitStr, collID, lang)
+	if err != nil {
+		log.Error("Failed selecting from posts: %v", err)
+		return nil, impart.HTTPError{http.StatusInternalServerError, "Couldn't retrieve collection posts."}
+	}
+	defer rows.Close()
+
+	// TODO: extract this common row scanning logic for queries using `postCols`
+	posts := []PublicPost{}
+	for rows.Next() {
+		p := &Post{}
+		err = rows.Scan(&p.ID, &p.Slug, &p.Font, &p.Language, &p.RTL, &p.Privacy, &p.OwnerID, &p.CollectionID, &p.PinnedPosition, &p.Created, &p.Updated, &p.ViewCount, &p.Title, &p.Content)
+		if err != nil {
+			log.Error("Failed scanning row: %v", err)
+			break
+		}
+		p.extractData()
+		p.augmentContent(c)
+		p.formatContent(cfg, c, includeFuture, false)
+
+		posts = append(posts, p.processPost())
+	}
+	err = rows.Err()
+	if err != nil {
+		log.Error("Error after Next() on rows: %v", err)
+	}
+
+	return &posts, nil
+}
+
 func (db *datastore) GetAPFollowers(c *Collection) (*[]RemoteUser, error) {
 	rows, err := db.Query("SELECT actor_id, inbox, shared_inbox FROM remotefollows f INNER JOIN remoteusers u ON f.remote_user_id = u.id WHERE collection_id = ?", c.ID)
 	if err != nil {

routes.go

@@ -216,6 +216,7 @@ func InitRoutes(apper Apper, r *mux.Router) *mux.Router {
 func RouteCollections(handler *Handler, r *mux.Router) {
 	r.HandleFunc("/logout", handler.Web(handleLogOutCollection, UserLevelOptional))
 	r.HandleFunc("/page/{page:[0-9]+}", handler.Web(handleViewCollection, UserLevelReader))
+	r.HandleFunc("/lang:{lang}", handler.Web(handleViewCollectionLang, UserLevelOptional))
 	r.HandleFunc("/tag:{tag}", handler.Web(handleViewCollectionTag, UserLevelReader))
 	r.HandleFunc("/tag:{tag}/feed/", handler.Web(ViewFeed, UserLevelReader))
 	r.HandleFunc("/sitemap.xml", handler.AllReader(handleViewSitemap))