Hi, just wanted understand if each custom field provided by apps is placed in different iframe. If so than what are possible ways for two fields provided by same app to interact with each other. For example when a value is set on one field than change options of other field.
As far as I know customFields are currently possible withour iframe or any sort of styling (with a few of atlassian supported types like select, radio). It may be possible to adjust another field by implementing a hook that will watch on issue changes.
In case you want/need to style your custom field, you may take a look at the forge custom fields. There are some examples where the Field is calculated (e.g. a number of comments/attachments)