Custom site name set on root HTML title (#21106)

* Site name set on HTML title

43924

* Added description meta tag.

* EscapeString added, variables name changed

* Update string check

* Re-organized methods

* Updated method

* one return to readability of function

* Update web/static.go

Co-authored-by: Tim Scheuermann <noxer@users.noreply.github.com>

Co-authored-by: Tim Scheuermann <noxer@users.noreply.github.com>
Co-authored-by: Mattermod <mattermod@users.noreply.github.com>
Co-authored-by: Mattermost Build <build@mattermost.com>

web/static.go

@@ -4,7 +4,11 @@
 package web
 
 import (
+	"bytes"
+	"fmt"
+	"html"
 	"net/http"
+	"os"
 	"path"
 	"path/filepath"
 	"strings"
@@ -73,7 +77,21 @@ func root(c *Context, w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Cache-Control", "no-cache, max-age=31556926, public")
 
 	staticDir, _ := fileutils.FindDir(model.ClientDir)
-	http.ServeFile(w, r, filepath.Join(staticDir, "root.html"))
+	contents, err := os.ReadFile(filepath.Join(staticDir, "root.html"))
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusNotFound)
+		return
+	}
+
+	titleTemplate := "<title>%s</title>"
+	originalHTML := fmt.Sprintf(titleTemplate, html.EscapeString(model.TeamSettingsDefaultSiteName))
+	modifiedHTML := getOpenGraphMetaTags(c)
+	if originalHTML != modifiedHTML {
+		contents = bytes.ReplaceAll(contents, []byte(originalHTML), []byte(modifiedHTML))
+	}
+
+	w.Header().Set("Content-Type", "text/html")
+	w.Write(contents)
 }
 
 func staticFilesHandler(handler http.Handler) http.Handler {
@@ -130,3 +148,27 @@ func unsupportedBrowserScriptHandler(w http.ResponseWriter, r *http.Request) {
 	templatesDir, _ := templates.GetTemplateDirectory()
 	http.ServeFile(w, r, filepath.Join(templatesDir, "unsupported_browser.js"))
 }
+
+func getOpenGraphMetaTags(c *Context) string {
+	siteName := model.TeamSettingsDefaultSiteName
+	customSiteName := c.App.Srv().Config().TeamSettings.SiteName
+	if customSiteName != nil && *customSiteName != "" {
+		siteName = *customSiteName
+	}
+
+	siteDescription := model.TeamSettingsDefaultCustomDescriptionText
+	customSiteDescription := c.App.Srv().Config().TeamSettings.CustomDescriptionText
+	if customSiteDescription != nil && *customSiteDescription != "" {
+		siteDescription = *customSiteDescription
+	}
+
+	titleTemplate := "<title>%s</title>"
+	titleHTML := fmt.Sprintf(titleTemplate, html.EscapeString(siteName))
+	descriptionHTML := ""
+	if siteDescription != "" {
+		descriptionTemplate := "<meta property=\"og:description\" content=\"%s\" />"
+		descriptionHTML = fmt.Sprintf(descriptionTemplate, html.EscapeString(siteDescription))
+	}
+
+	return titleHTML + descriptionHTML
+}