How to retrieve a document from a sub-process to a main-process via a call activity

If you have ever wondered how to retrieve a document from a sub-process after a call activity, this article is for you.

As documented, you can follow this article to retrieve a document in a sub-process that was previously uploaded in a main-process:
https://documentation.bonitasoft.com/bonita/7.9/documents#toc3

In the other hand, to do the opposite you can follow the steps of this example :

In the sub-pool

1) We create a human task containing a simple upload widget ;
2) We store the "rootProcessInstanceId" (under General->Search keys);

In the main-pool

1) We create a call-activity calling our sub-pool;
2) We create after a service task that searches among archived processes the human task of the sub-pool (and get the submitted document);
In our example, we used a "Script" under "Operations".

You find on the following link an simple projet performing the steps above (Bonita 7.8.4):
https://drive.google.com/file/d/1orUb23o21d_iUgITDFf-DXKwq0BewTed/view?u...

I hope this article helps.