title: How can I set the approvers for all steps in an approval process?
body: <p>I have an approval process with three steps, all of which are set to Assigned Approver = Manually Chosen. When the user submits the record for approval, I'd like to have Apex code determine who the three approvers are. However, I don't see a way to hook into the approve request submission. </p>
  
  <p>If I submit the approval with Apex Using <code>Approval.process()</code>, I can set the initial (and only the initial) approver with <code>ProcessSubmitRequest.setNextApproverIds()</code>. This call leads you to believe you can specify multiple approvers since it takes an array of Ids, but the array can only have 1 element, or else runtime a error occurs. </p>
  
  <p>Once I know what the first approver's response is, I can use Apex to submit her response and, again, set the immediately next approver by passing a <code>ProcessWorkitemRequest</code> instance to <code>Approval.process()</code>. An important note here is that the approver must not approve via the standard UI. Instead, they must do something that invokes the Apex code so that we can set who the next approve should be. A trigger on the object under review, or a custom button + VF page could be used to invoke the Apex.</p>
  
  <p>My main question is, how can I make sure that the user does not use the standard approval buttons? They appear in the Approvals related list and on the salesforce home screen. It may be in other places as well. Again, if they use the standard submit and approve buttons, I don't have any way to hook in to set the next approver.</p>