Index: openacs-4/packages/file-storage/www/file-add.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/file-storage/www/file-add.tcl,v
diff -u -r1.26 -r1.27
--- openacs-4/packages/file-storage/www/file-add.tcl	7 Dec 2018 11:34:52 -0000	1.26
+++ openacs-4/packages/file-storage/www/file-add.tcl	7 Dec 2018 11:54:31 -0000	1.27
@@ -38,7 +38,8 @@
         set n_bytes [file size ${upload_file.tmpfile}]
         set max_bytes [fs::max_upload_size]
         if { $n_bytes > $max_bytes } {
-            ad_complain "Your file is larger than the maximum file size allowed on this system ([util_commify_number $max_bytes] bytes)"
+            set number_of_bytes $max_bytes ; # needed by message key
+            ad_complain [_ file-storage.lt_Your_file_is_larger_t]
         }
     }
 }
@@ -65,16 +66,33 @@
 }
 set context [fs_context_bar_list -final $page_title $folder_id]
 
+set max_upload_size [fs::max_upload_size]
 ad_form -html { enctype multipart/form-data } \
     -export { folder_id lock_title_p name return_url } \
     -form {
         file_id:key
         {upload_file:file
             {label "#file-storage.Upload_a_file#"}
             {html "size 30"}
+            {help_text "[_ file-storage.Upload_Limit]: $max_upload_size"}
         }
     }
 
+# Try to prevent upload of too big files from the client side. Saves
+# us some useless requests and gives a quicker feedback to the user.
+set number_of_bytes $max_upload_size ; # needed by message key
+set file_too_big_msg [_ file-storage.lt_Your_file_is_larger_t]
+template::add_event_listener -event submit -id file-add \
+    -preventdefault=false -script [subst -nocommands {
+    var uploadFileField = this.elements.namedItem('upload_file');
+    var uploadFile = uploadFileField.files[0];
+    if (uploadFile != undefined &&
+        uploadFile.size > $max_upload_size) {
+        alert('$file_too_big_msg');
+        event.preventDefault();
+    }
+}]
+
 if {[parameter::get -parameter AllowTextEdit -default 0]} {
     if {[ad_form_new_p -key file_id]} {
         # To allow the creation of files