How to add a listener by event?

[JianiYang]

I want to add a check to make sure user will save before exit. And I found that there is a vue-formular.change event might be useful , but i can't use it as a common VUE event .Is there any samples to use a event ?

[JianiYang]

Is there any way that can watch when the from's item value been changed?

[matfish2]

As documented you can listen to a change event on any field. Say your field name is title:

this.$on('vue-formular.change::title', function(data) {

});

[JianiYang]

thanks ,but I want to know that how can I listen all sub-item of the from or I need to add the function one by one ?

[matfish2]

Again, as documented, you can use the global vue-formular.change event, which is emitted for any field.