onBeforeFileAdd

fires the moment you try to add file to uploader

Example

$$("uploader_1").attachEvent("onBeforeFileAdd", function(file){
    var type = file.type.toLowerCase();
    if (type != "jpg" && type != "png"){
        webix.message("Only PNG or JPG images are supported");
        return false;
    }
});

Related samples

The file object contains the following properties:

• id (number) - the file ID generated automatically with the webix.uid() method per each uploading session
• name (string) - the file title and extension
• file (object) - File object
• percent (number) - the indicator of the loading progress
• size (number) - the size of the file in bytes (as a number)
• sizetext (string) - the size of the file as a string, like "522Kb"
• sname (string) - the file name under which it was saved on server
• status (string) - the upload status that changes during uploading:
  • "client" - the file is added to the uploader body on the client side, the uploading hasn't been started yet or was aborted by a user
  • "transfer" - the file uploading is in progress
  • "server" - the file has been successfully uploaded
  • "error" - an error occurred during uploading
• type (string) - the file extension.

If the method returns false further processing of a file (i.e. adding it to the client-side storage and uploading) will be blocked.