As you build out more workflows in Nintex Workflow Cloud, you'll find that reusable workflow design is going to be critical. The concept of Component Workflows in NWC is awesome and the best way to do this.
In the video above, I show you how using a start Form with attachments requires that you configure a Default File Storage. This means all your attachments will go there. At the end of the workflow, you probably want to clean up that data. Whether it's Box, OneDrive, DropBox etc, you can do something very similar with each one. In my example, I'm using Box.
The Component Workflow can take an number of input parameters. I'd recommend two text parameters. A Folder name and a Parent Workflow Instance ID. The reason is, when the workflow runs, it'll store attachments in a folder that it will create and the name it uses is the workflow instance ID. The Folder name parameter, is the location in the Box environment where the workflow will create that other guid folder and store the files in. This is everything the Component Workflow needs to find all the files it needs to delete and then also delete that folder.
I've provided my workflow Export Key below. You can import it into NWC, but you will need to modify it, since you probably don't have a connection called "Box Nintex". Update the three Box actions, or if you're using a different EFSS, replace those actions with the appropriate ones you need.
The other important thing to note, is that when you publish a Component Workflow, you'll get an Open API specification URL. Copy that, and then go to NWC Xtensions and paste it in. Your component workflow now becomes an action you can use in any number of other workflows. It's pretty cool.
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Nintex Workflow Cloud - Box Cleanup Attachments Component Workflow - c8dab41894494e8aa28d2e6d4556087f