Queue-Based Document Approval Pipeline

Overview

A SharePoint-triggered, multi-stage document approval flow that uses Azure Queues as a handoff bus between approval stages. Every transition (initial submission, Stage 1 outcome, Stage 2 outcome) writes a structured JSON message to the Azure Queue so downstream observers, audit pipelines, or other Power Automate flows can subscribe to lifecycle events without coupling to the SharePoint list directly. Stage 1 (Manager) and Stage 2 (Director) approvals are blocking via the Approvals connector, and the SharePoint item is patched with the final disposition (Fully Approved, Rejected at Stage 1, or Rejected at Stage 2).

Use Case

Use this pattern when document approvals need multi-stage gating with auditable handoff events and loose coupling between the orchestrator and downstream systems. Typical real-world fits: contract approvals, capital expenditure requests, change management for security policies, compliance attestations, and any two-tier sign-off flow where the trail of state transitions is itself a deliverable.

The flow is ideal for teams that:

• Sequential multi-stage gating (Manager → Director) where Stage 2 only fires if Stage 1 approves
• Auditable, replayable handoff events captured outside the primary record (Azure Queue lets a separate flow drain handoff messages into Dataverse, Splunk, an Event Hub, or a data warehouse)
• Loose coupling between the approval orchestrator and downstream systems — they consume the queue, not the SharePoint list
• Disposition writeback to the originating list so requestors and dashboards can read the final status without polling Approvals

Flow Architecture

Environment Variables

Connectors & Connections

Note — All connections are referenced as solution connection references; the flow is portable between environments as long as a connection is mapped at import time.

Customization Guide

Almost every realistic variant of this flow can be implemented by changing environment variable values. A few cases require small edits inside the flow definition — those are called out explicitly below.

Add more approval stages

Duplicate the Stage2_Director_Approval + Compose_Stage*_Result_Message + Put_Stage*_Result_To_Queue triplet inside the If_Stage2_Approved Yes branch and shift the SharePoint update further down the chain. Each new stage gets its own env var for the approver email and a corresponding Status literal in the PatchItem.

Change the queue cadence or go event-driven

To make the trigger more responsive, shorten the recurrence.interval on When_Document_Approval_Item_Is_Created (minimum 1 minute). For an event-driven model, replace the SharePoint trigger with shared_azurequeues/OnNewMessageInQueue and read the document metadata from the message body itself.

Route by document category

Add a Switch action after Init_varListItemId that branches on a SharePoint column (e.g., Category) and points each case at a different flowlibs_ApprovalStage1Approver* env var. The queue messages can carry the category for downstream consumers to filter.

Replace Approvals with Adaptive Cards

Swap each StartAndWaitForAnApproval action for shared_teams/PostAdaptiveCardAndWaitForAResponse. The outcome field changes from body/outcome to a custom card response field, and the If expressions need to compare against the card's submit value. The queue handoff pattern stays identical.

Add a queue drainer flow

Build a separate FlowLibs flow with shared_azurequeues/OnNewMessageInQueue trigger pointing at the same queue. Parse the JSON body and route to Dataverse CreateRecord, Splunk HEC, or Event Hubs based on the stage field (submitted, stage1-result, stage2-result). Canonical way to extend the pipeline without modifying the orchestrator.

Key Expressions

The flow is intentionally light on Power Fx / WDL gymnastics — the heaviest expressions are the branch-name concatenation and the approval outcome check. They are listed below in the order they appear in the flow.

string(triggerOutputs()?['body/ID'])

coalesce(triggerOutputs()?['body/Author/Email'], '')

json(concat('{"stage":"submitted","docTitle":"', variables('varDocumentTitle'), '", ...}'))

string(outputs('Compose_Initial_Queue_Message'))

body('Stage1_Manager_Approval')?['outcome']

variables('varListItemId')