Subscription in tableau server is specifically based on TIME. It makes more sense if there is also a feature of ''Subscribing to view/workbook based on the extract refresh".
My situation is worse using bat files. We have a batch file that triggers extract refresh based on the back end oracle tables refresh. Once the refresh is successfully completed then there is another batch file which gets triggered to generate .pdf for those workbooks dependent on extracts. As every time a new view adds up we need to manually change the script to generate the pdf. This is one **** of a process that we are going now.
Instead Tableau can consider adding ''AFTER EXTRACT REFRESH'' in the subscription drop down. Which would actually generate a pdf after the extract refresh is done.
As of now we have time based subscriptions which is actually good for some use cases but not all.
If Tableau fulfills this case then we can actually get rid of all these .bat files.