title: Saving values in custom smart filter field
body: <p>In this smart filter example: <a href="https://sapui5.hana.ondemand.com/#/sample/sap.ui.comp.sample.smartfilterbar.example2/preview" rel="nofollow noreferrer">https://sapui5.hana.ondemand.com/#/sample/sap.ui.comp.sample.smartfilterbar.example2/preview</a></p>
  
  <p>.. a custom field is used. It's defined like this:</p>
  
  <pre><code>&lt;smartFilterBar:ControlConfiguration
      key="MyOwnFilterField" index="1" label="Custom Filter Field"
      groupId="_BASIC" width="300px" mandatory="mandatory"
      visibleInAdvancedArea="true"&gt;
  
      &lt;smartFilterBar:customControl&gt;
        &lt;m:Select id="foo" customData:hasValue="true"&gt;
          &lt;core:Item key="1" text="ONE"/&gt;
          &lt;core:Item key="2" text="TWO"/&gt;
          &lt;core:Item key="3" text="THREE"/&gt;
        &lt;/m:Select&gt;
      &lt;/smartFilterBar:customControl&gt;
  
  &lt;/smartFilterBar:ControlConfiguration&gt;
  </code></pre>
  
  <p>The values and selected keys of all fields are saved when the variant is saved, <em>except</em> for the values in the custom field. </p>
  
  <p>I also want to store the values in the custom field, in the example it's a select. Is there a way to do that?</p>