title: fluent ui - How to display/overlay a Spinner component in a TextField where iconProps usually renders the icon?
body: <p>I want the <a href="https://developer.microsoft.com/en-us/fluentui#/controls/web/textfield" rel="nofollow noreferrer">TextField</a> to conditionally display the Spinner component exactly where an icon would render if you pass an icon to iconProps. I got the conditional rendering of the icon and spinner but I couldn't figure out how to include a component into TextField. So, I think the best way might be to possibly to overlay? Here is my <a href="https://codepen.io/chrichung/pen/dyZexVy" rel="nofollow noreferrer">codepen</a> for trying to overlay the Spinner component</p>
  <pre><code>
  // Initialize icons in case this example uses them
  initializeIcons();
  
  const stackTokens = { childrenGap: 50 };
  const iconProps = { iconName: 'Edit' };
  const stackStyles: Partial&lt;IStackStyles&gt; = { root: { width: 650 } };
  const columnProps: Partial&lt;IStackProps&gt; = {
    tokens: { childrenGap: 15 },
    styles: { root: { width: 300 } },
  };
  
  const TextFieldBasicExample: React.FunctionComponent = () =&gt; {
    return (
       &lt;Stack horizontal tokens={stackTokens} styles={stackStyles}&gt;
          &lt;div style={{height: &quot;100%&quot;, margin: &quot;15px&quot; }}&gt;
            &lt;Stack {...columnProps}&gt;        
                &lt;TextField label=&quot;With an icon&quot; iconProps={iconProps} styles={{ root: { position: &quot;absolute&quot;,zIndex: 1, width: &quot;340px&quot; } }}/&gt;  
              &lt;/Stack&gt;
  
              &lt;div style={{display: &quot;flex&quot;,
                zIndex: 13,
                // position: &quot;absolute&quot;,
                // backgroundColor: &quot;red&quot;, 
                justifyContent: &quot;end&quot;}}&gt;
                &lt;span style={{padding: &quot;0px 24px 0px 8px&quot;}}&gt;
                  &lt;Spinner /&gt;
                 &lt;/span&gt;                    
              &lt;/div&gt;          
           &lt;/div&gt;  
       &lt;/Stack&gt; 
    );
  };
  
  const TextFieldBasicExampleWrapper = () =&gt; &lt;ThemeProvider&gt;&lt;TextFieldBasicExample /&gt;&lt;/ThemeProvider&gt;;
  ReactDOM.render(&lt;TextFieldBasicExampleWrapper /&gt;, document.getElementById('content'))````
  
  </code></pre>