Handle issues arising from objects in data structure by throwing error (

#921)

* Handle issues arrising from objects in data structure by throwing error

* Better attempt takes null and array into account, which are allowed

src/MUIDataTable.js

@@ -454,7 +454,7 @@ class MUIDataTable extends React.Component {
   transformData = (columns, data) => {
     const leaf = (obj, path) => path.split('.').reduce((value, el) => (value ? value[el] : undefined), obj);
 
-    return Array.isArray(data[0])
+    const transformedData = Array.isArray(data[0])
       ? data.map(row => {
           let i = -1;
 
@@ -464,6 +464,12 @@ class MUIDataTable extends React.Component {
           });
         })
       : data.map(row => columns.map(col => leaf(row, col.name)));
+
+      // We need to determine if object data exists in the transformed structure, as this is currently not allowed
+      const hasInvalidData = transformedData.filter(data => data.filter(d => typeof d === 'object' && d !== null && !Array.isArray(d)).length > 0).length > 0;
+      if (hasInvalidData) throw Error(`Cannot accept objects for cell data. Cells need to contain strings | numbers. It\'s possible this error is the result of a missing dot in the column name field (e.g. name: "company" instead of name: "company.id")`);
+
+      return transformedData;
   };
 
   setTableData(props, status, callback = () => {}) {