MM-22845: Added support for permalink previews. (#17796)

* MM-22845: Added support for permalink previews.

* MM-22845: Adds license to new file.

* MM-22845: Adds endpoint to retrieve multiple posts by id.

* MM-22845: Fix for deleted post.

* MM-22845: Adds config setting for permalink previews.

* MM-22845: Adds API test for new endpoint.

* MM-22845: Fix typo.

* MM-22845: Tests that post create or updated via App get the previewed_post prop.

* MM-22845: Tests for matching permalinks.

* MM-22845: Adds PreparePostForClient test for permalink previews.

* MM-22845: Embeds entire post in permalink metadata.

* MM-22845: Filter WS message payload of created and edited post based on permissions.

* MM-22845: Runs app layer generator.

* MM-22845: Lint check fix.

* MM-22845: Adds feature flag.

* MM-22845: Clones WS message.

* MM-22845: Removes knowledge of permalink from LinkMetadata table. Removes knowledge of user id from post embedding methods in favour of a 'sanitize' method/step.

* MM-22845: Handle nil post metadata.

* MM-22845: Switch to cloning post.

* MM-22845: Removes unused code.

* MM-22845: Refactor.

* MM-22845: Reverts whitespace change.

* MM-22845: Removes unnecessary code.

* MM-22845: Removes unnecessary function.

* MM-22845: Warn but don't error if permalinked referenced post or channel is not found.

* MM-22845: Fix for clone method.

* MM-22845: Fix for clone method.

* MM-22845: Updates translations.

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

api4/channel.go

@@ -722,6 +722,11 @@ func getPinnedPosts(c *Context, w http.ResponseWriter, r *http.Request) {
 	}
 
 	clientPostList := c.App.PreparePostListForClient(posts)
+	clientPostList, err = c.App.SanitizePostListMetadataForUser(clientPostList, c.AppContext.Session().UserId)
+	if err != nil {
+		c.Err = err
+		return
+	}
 
 	w.Header().Set(model.HeaderEtagServer, clientPostList.Etag())
 	if err := json.NewEncoder(w).Encode(clientPostList); err != nil {

api4/post.go

@@ -128,6 +128,11 @@ func createEphemeralPost(c *Context, w http.ResponseWriter, r *http.Request) {
 	w.WriteHeader(http.StatusCreated)
 	rp = model.AddPostActionCookies(rp, c.App.PostActionCookieSecret())
 	rp = c.App.PreparePostForClient(rp, true, false)
+	rp, err := c.App.SanitizePostMetadataForUser(rp, c.AppContext.Session().UserId)
+	if err != nil {
+		c.Err = err
+		return
+	}
 	if err := json.NewEncoder(w).Encode(rp); err != nil {
 		mlog.Warn("Error while writing response", mlog.Err(err))
 	}
@@ -216,6 +221,11 @@ func getPostsForChannel(c *Context, w http.ResponseWriter, r *http.Request) {
 
 	c.App.AddCursorIdsForPostList(list, afterPost, beforePost, since, page, perPage, collapsedThreads)
 	clientPostList := c.App.PreparePostListForClient(list)
+	clientPostList, err = c.App.SanitizePostListMetadataForUser(clientPostList, c.AppContext.Session().UserId)
+	if err != nil {
+		c.Err = err
+		return
+	}
 
 	if err := json.NewEncoder(w).Encode(clientPostList); err != nil {
 		mlog.Warn("Error while writing response", mlog.Err(err))
@@ -274,6 +284,11 @@ func getPostsForChannelAroundLastUnread(c *Context, w http.ResponseWriter, r *ht
 	postList.PrevPostId = c.App.GetPrevPostIdFromPostList(postList, collapsedThreads)
 
 	clientPostList := c.App.PreparePostListForClient(postList)
+	clientPostList, err = c.App.SanitizePostListMetadataForUser(clientPostList, c.AppContext.Session().UserId)
+	if err != nil {
+		c.Err = err
+		return
+	}
 
 	if etag != "" {
 		w.Header().Set(model.HeaderEtagServer, etag)
@@ -337,7 +352,13 @@ func getFlaggedPostsForUser(c *Context, w http.ResponseWriter, r *http.Request)
 	}
 
 	pl.SortByCreateAt()
-	if err := json.NewEncoder(w).Encode(c.App.PreparePostListForClient(pl)); err != nil {
+	clientPostList := c.App.PreparePostListForClient(pl)
+	clientPostList, err = c.App.SanitizePostListMetadataForUser(clientPostList, c.AppContext.Session().UserId)
+	if err != nil {
+		c.Err = err
+		return
+	}
+	if err := json.NewEncoder(w).Encode(clientPostList); err != nil {
 		mlog.Warn("Error while writing response", mlog.Err(err))
 	}
 }
@@ -355,6 +376,11 @@ func getPost(c *Context, w http.ResponseWriter, r *http.Request) {
 	}
 
 	post = c.App.PreparePostForClient(post, false, false)
+	post, err = c.App.SanitizePostMetadataForUser(post, c.AppContext.Session().UserId)
+	if err != nil {
+		c.Err = err
+		return
+	}
 
 	if c.HandleEtag(post.Etag(), "Get Post", w, r) {
 		return
@@ -434,6 +460,11 @@ func getPostThread(c *Context, w http.ResponseWriter, r *http.Request) {
 	}
 
 	clientPostList := c.App.PreparePostListForClient(list)
+	clientPostList, err = c.App.SanitizePostListMetadataForUser(clientPostList, c.AppContext.Session().UserId)
+	if err != nil {
+		c.Err = err
+		return
+	}
 
 	w.Header().Set(model.HeaderEtagServer, clientPostList.Etag())
 
@@ -507,6 +538,11 @@ func searchPosts(c *Context, w http.ResponseWriter, r *http.Request) {
 	}
 
 	clientPostList := c.App.PreparePostListForClient(results.PostList)
+	clientPostList, err = c.App.SanitizePostListMetadataForUser(clientPostList, c.AppContext.Session().UserId)
+	if err != nil {
+		c.Err = err
+		return
+	}
 
 	results = model.MakePostSearchResults(clientPostList, results.Matches)