Added download param to getFile api call

api/file.go

@@ -379,6 +379,7 @@ func getFile(c *Context, w http.ResponseWriter, r *http.Request) {
 	hash := r.URL.Query().Get("h")
 	data := r.URL.Query().Get("d")
 	teamId := r.URL.Query().Get("t")
+	isDownload := r.URL.Query().Get("download") == "1"
 
 	cchan := Srv.Store.Channel().CheckPermissionsTo(c.Session.TeamId, channelId, c.Session.UserId)
 
@@ -420,16 +421,18 @@ func getFile(c *Context, w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Length", strconv.Itoa(len(f)))
 	w.Header().Del("Content-Type") // Content-Type will be set automatically by the http writer
 
-	// attach extra headers to trigger a download on IE, Edge, and Safari
-	ua := user_agent.New(r.UserAgent())
-	bname, _ := ua.Browser()
+	if isDownload {
+		// attach extra headers to trigger a download on IE, Edge, and Safari
+		ua := user_agent.New(r.UserAgent())
+		bname, _ := ua.Browser()
 
-	if bname == "Edge" || bname == "Internet Explorer" || bname == "Safari" {
-		// trim off anything before the final / so we just get the file's name
-		parts := strings.Split(filename, "/")
+		if bname == "Edge" || bname == "Internet Explorer" || bname == "Safari" {
+			// trim off anything before the final / so we just get the file's name
+			parts := strings.Split(filename, "/")
 
-		w.Header().Set("Content-Type", "application/octet-stream")
-		w.Header().Set("Content-Disposition", "attachment;filename=\""+parts[len(parts)-1]+"\"")
+			w.Header().Set("Content-Type", "application/octet-stream")
+			w.Header().Set("Content-Disposition", "attachment;filename=\""+parts[len(parts)-1]+"\"")
+		}
 	}
 
 	w.Write(f)

web/react/components/view_image.jsx

@@ -211,7 +211,7 @@ export default class ViewImageModal extends React.Component {
         }
 
         const filename = this.props.filenames[this.state.imgId];
-        const fileUrl = Utils.getFileUrl(filename);
+        const fileUrl = Utils.getFileUrl(filename, true);
 
         var content;
         if (this.state.loaded[this.state.imgId]) {
@@ -377,6 +377,7 @@ function ImagePreview({filename, fileUrl, fileInfo, maxHeight}) {
         <a
             href={fileUrl}
             target='_blank'
+            download={true}
         >
             <img
                 style={{maxHeight}}

web/react/utils/utils.jsx

@@ -1091,8 +1091,9 @@ export function fileSizeToString(bytes) {
 }
 
 // Converts a filename (like those attached to Post objects) to a url that can be used to retrieve attachments from the server.
-export function getFileUrl(filename) {
-    return getWindowLocationOrigin() + '/api/v1/files/get' + filename + '?' + getSessionIndex();
+export function getFileUrl(filename, isDownload) {
+    const downloadParam = isDownload ? '&download=1' : '';
+    return getWindowLocationOrigin() + '/api/v1/files/get' + filename + '?' + getSessionIndex() + downloadParam;
 }
 
 // Gets the name of a file (including extension) from a given url or file path.