How to compute using nested fields?

[nareshbhatia]

Are you submitting a bug report or a feature request?

Feature request

What is the current behavior?

The example shows computations using top level fields.

What is the expected behavior?

Can you please provide an example that computes using nested fields? For example, I need to compute a date object (startTime), based on date and time fields (datePart and timePart) that are nested in a meeting object.

<Field
    name="meeting.datePart"
    component={TextField}
    type="text"
    label="Start Date"
/>
<Field
    name="meeting.timePart"
    component={TextField}
    type="text"
    label="Time"
/>
<Field
    name="meeting.startTime"
    component={TextField}
    type="text"
    label="Start Time"
/>

[svetlanapuro]

There is an example in the doc for nested fields:

{
    field: /\.timeFrom/, // when a deeper field matching this pattern changes...
    updates: (value, name, allValues) => {
      const toField = name.replace('timeFrom', 'timeTo')
      const toValue = getIn(allValues, toField)
      if (toValue && value > toValue) {
        return {
          [toField]: value
        }
      }

      return {}
    }
  }