the fiddle example (http://zkfiddle.org/sample/4b9qh0/22-ZK-7-jq-selector-problem) shows the problem in the console log

some jq selector syntax based on widget type (@datebox) or widget id ($widget-id) fail to find the children

cases A, B, G which worked in ZK 6.5.x don't work anymore in ZK >=7.0.0 (can be reproduced in ZKfiddle watching the browser console)

several workarounds are shown in C-F and H