workaround: file open for each data harmonizer

lib/Toolbar.js

@@ -114,7 +114,6 @@ class Toolbar {
     const $fileInput = $('#open-file-input');
 
     $fileInput.on('change', function () {
-      const dh = self.context.getCurrentDataHarmonizer()
       const file = $fileInput[0].files[0];
       const ext = file.name.split('.').pop();
       const acceptedExts = ['xlsx', 'xls', 'tsv', 'csv', 'json'];
@@ -123,18 +122,18 @@ class Toolbar {
         $('#open-err-msg').text(errMsg);
         $('#open-error-modal').modal('show');
       } else {
-        dh.invalid_cells = {};
         // open for all data harmonizers
+        // TODO: refactor to context function, there's too much redundant work being done here
         Object.values(self.context.dhs).forEach(dh => {
+          dh.invalid_cells = {};
           dh.runBehindLoadingScreen(dh.openFile.bind(dh), [file]);
+          dh.current_selection = [null, null, null, null];
         })
         $('#file_name_display').text(file.name);
       }
       // Allow consecutive uploads of the same file
       $fileInput[0].value = '';
-
       self.hideValidationResultButtons();
-      dh.current_selection = [null, null, null, null];
     });
 
     // File -> Save