fix: drop event will not trigger excelPreview @ init

js/src/excel-preview.js

@@ -32,7 +32,12 @@
         init: function () {
             var e = this;
             let input = $(e.element).prev('input[type=file]');
-            $(e.element).prev('input[type=file]').fileinput(e.settings).on('change', function (file) {
+            let namespace = input.data('fileinput').namespace;
+            input.fileinput(e.settings).on('change', function (file) {
+                e.excelPreview(file);
+            })
+            /* let drop event trigger change*/
+            input.on('change' + namespace, function (file){
                 e.excelPreview(file);
             })
         },