I am afraid that what you would like to achieve is not supported. Generally speaking, the DataSource have an autoSync option which if set to true will invoke the sync() method after each change made. Auto-syncing however is not yet supported in the HierarchicalDataSource. For more information please check this forum thread
Another issue with the provided example is that new records has an ID, which is why they are not considered as new, but as modified. Respectively the DataSource will attempt to submit them through the update transport.
In order to insert new records, you should at first define the model ID field in the DataSource.schema.model
configuration. Then the newly added items (nodes) should not have assigned ID. This thread
discusses the same issue.
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