To the questions:
1) The default value object is executed on the server side (before the items are actually send to the client) and this #= # expression won't be evaluated. If you want to change the default values you will need to manually update the DataSource configuration when the Grid is initialized.
As a work-around you can dynamically update the model , when the edit or save events are triggered and retrieve that value from the master Grid. e.g.
parentGrid = $(
parentRow = e.container.closest(
parentDataItem = parentGrid.dataItem(parentRow);
2) Please demonstrate your case with a small demo so we can investigate why those events inside of the widgets inside the editor templates are not runnable.
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