Hi,
if you don't want to use javascript (or you can explain what are these security reasons) you can write a plugin that will update the textfield when the record is created and updated. The user will see the value only after he saves the record, will not see the
change in real-time (as will happen using javascript).
You can't trigger directly a plugin when the onchange event occurs (can be triggered indirectly but in that case you need to use javascript, and if can use javascript is useless to use a plugin for this purpose)
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