updating task predecessors

[KristenS_WF]

Is it possible to update task predecessors through Fusion?  I just kick-started a group of 30+ projects, and I need to add cross-project predecessors to a specific task in each project.

When assigning predecessors last year (prior to us having Fusion access), I created a task report and pasted in the predecessor values using the project reference and task numbers (e.g., '1988778:24,1988827:24,1988974:24').

I'm pretty new to Fusion.  I've been able to download/parse CSV files and update tasks for basic info (assignees; planned start dates; etc.), but Predecessors is not one of the available options in the field list for the Task object.  Can the predecessors be mapped through the mapping panel?  If so, what would that expression be?  I'm not advanced enough at this point to go the API route (and I'm not even sure our IT department has obtained the API package in Fusion).

Thanks.

[ChrisStephens]

Yes, you can update task predecessors using Fusion, but unfortunately you can't use the default Workfront modules, you have to use the Workfront Custom API module, and interact with the field predecessorExpression.

[ChrisStephens · Accepted solution]

Here is how to configure the module to update a specific task's predcessors.

URL field: TASK/{the task ID that you want to update}

Method field: PUT

Body field: this string -> {"predecessorExpression": "####"}

In the body field, replace #### with the task number of the predecessor task, so for a cross-project predecessor you would replace it with a number like 16700:5. 

One note, if the task already has predecessors and you just want to add a new one, you need to pull in the current predecessors and add the new one to the string. Just passing the new predecessor will overwrite whatever is already there with the new one.

[KristenS_WF]

Thanks, Chris!  This is very helpful.