Print module with erpal lists (eg tasks)

There was a feature request about #1992782: PDF print for lists and #2050401: task print function broken, with status won’t fix. Indeed, since print module integrates well with erpal lists, there’s no need for feature request. That’s why I have opened this as documentation issue.

First of all, print module (https://www.drupal.org/project/print 7.x-2.0 tested version), plays well with views. ( despite common confusion after reading front page module).
See: #1421724: Printing views?, module’s FAQ https://www.drupal.org/node/190173#views , #1703088: Exposed Filters Views Integration with already commited #1322222: Problem with URL parameters in D7

Short version implementation: Your task list /node/%node/tasks turns into printable at print/node/%node/tasks or printpdf/node/%node/tasks .

If you want to use completely different layout for printing tasks, you could use the following trick:
Setup a different view ( let’s call it print_tasks). This could be a page view or better a view pane cloned from main tasks views, included via page manager/panels in mytask/%node
You can change the template of print_tasks, to fit your printing needs.
Make sure that new view print_tasks has the same expoxed filters as original task view. ( You can get rid of the print $exposed; in template, cause you don’t want to print exposed filter)

Conclusion(eg): On /node/%node/tasks?nid=&title=test setup a dynamic link to /printpdf/mytask/%node?nid=&title=test

In order to do it in the elegant Erpal way, via CAT - Context local actions and tabs, the patch #2587509: New hook_cat_action_item_alter() and hook_cat_tab_item_alter() is required.