fix(Table): use Checkbox isChecked null for indeterminate state

Use the PatternFly Checkbox component's native indeterminate support
by setting isChecked to null instead of manually setting the DOM property.
This is the correct way to show indeterminate state in PatternFly checkboxes.

Author: rhamilto

packages/react-table/src/components/Table/SelectColumn.tsx

@@ -1,4 +1,4 @@
-import { createRef, Fragment, useEffect } from 'react';
+import { createRef, Fragment } from 'react';
 import { Tooltip, TooltipProps } from '@patternfly/react-core/dist/esm/components/Tooltip';
 import { Checkbox } from '@patternfly/react-core/dist/esm/components/Checkbox';
 import { Radio } from '@patternfly/react-core/dist/esm/components/Radio';
@@ -40,16 +40,19 @@ export const SelectColumn: React.FunctionComponent<SelectColumnProps> = ({
 }: SelectColumnProps) => {
   const inputRef = createRef<any>();
 
-  useEffect(() => {
-    if (inputRef.current && selectVariant === RowSelectVariant.checkbox) {
-      inputRef.current.indeterminate = !!isIndeterminate;
-    }
-  }, [inputRef, isIndeterminate, selectVariant]);
-
   const handleChange = (event: React.FormEvent<HTMLInputElement>, _checked: boolean) => {
     onSelect && onSelect(event);
   };
 
+  // PatternFly Checkbox supports indeterminate via isChecked: null
+  const checkboxProps = {
+    ...props,
+    id,
+    ref: inputRef,
+    onChange: handleChange,
+    ...(isIndeterminate && { isChecked: null })
+  };
+
   const commonProps = {
     ...props,
     id,
@@ -60,7 +63,7 @@ export const SelectColumn: React.FunctionComponent<SelectColumnProps> = ({
   const content = (
     <Fragment>
       {selectVariant === RowSelectVariant.checkbox ? (
-        <Checkbox {...commonProps} />
+        <Checkbox {...checkboxProps} />
       ) : (
         <Radio {...commonProps} name={name} />
       )}