import {
  findNodeHandle
} from 'react-native'


this.childItem.measureLayout(findNodeHandle(this.containerWrapper), (x, y, width, height) => {
  console.log('got measurement', x, y, width, height)
})

// example render

<container-wrapper ref={ref => this.containerWrapper = ref}>
  <item ref={ref => this.childItem = ref } />
</container-wrapper>