There is an issue with MultiValue fields being used within traits and the Preview App. User receives following error when adding a value to the field:

Failed to dispatch context property change: java.util.LinkedHashMap cannot be cast to javax.jcr.Node
java.lang.ClassCastException: java.util.LinkedHashMap cannot be cast to javax.jcr.Node

I have tested this on 6.1 and 6.2 and had different results. With 6.1 , I was able to add more Items to my MultiValue field and had no errors. On 6.2, I used two different configurations, one was with the old MultiValue names (i.e.info.magnolia.ui.form.field.definition.MultiValueFieldDefinition) and its respective configs, the other was with info.magnolia.ui.field.JcrMultiFieldDefinition.

With the older config, I was able to add more Items to my list, but the above error kept showing. When using the new class name (JcrMultFieldDefinition), the error showed as well.

I have attached the configs I have used for both 6.1 and 6.2 along with their converter, voter and trait class.

Dev notes

We could bind to this map via JCR API - expose map as a mocked JCR node instead of LinkedHashMap