Power Automate Flows to Mermaid Diagrams with OfficeScript

This repository contains an OfficeScript function that generates a Mermaid diagram from a flow definition (in JSON format) retrieved via Power Automate. The diagram visualizes the flow—including actions and dependencies—using enhanced styling with Mermaid subgraphs for conditions, switches, and scopes.

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Overview

The main function, main, performs the following tasks:

• JSON Parsing & Validation:
  Parses a JSON string representing a flow definition. If the JSON structure is invalid or the expected actions cannot be found, an error is thrown.

• Global Actions Mapping:
  Recursively builds a map of all actions (including nested actions) to handle dependencies correctly.

• Mermaid Diagram Construction:
  Generates a Mermaid diagram (in string format) that represents the flow. It creates nodes for actions, connects them based on dependencies (using runAfter), and uses subgraphs for complex actions like conditions and switches.

• Custom Styling:
  Applies specific styles and shapes based on the action type (for example, diamond for conditions, rectangle for simple actions).

• Logging:
  Outputs informational and warning messages during processing to assist with debugging.

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Retrieving the Flow Definition

1. Use the Get Flow as Admin Connector

   In Power Automate, add the Get Flow as Admin connector:

   • Provide the Environment and Flow IDs.
   • Under Advanced parameters, set Include Flow Definition to Yes.

   The flow definition is then accessible via:

   outputs('Get_Flow_as_Admin')?['body/properties/definition']
   

   

   This screenshot shows the setup of the Get Flow as Admin connector.

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Hosting and Running the OfficeScript

Hosting the OfficeScript

1. Save the Script in Excel Online

   • Open Excel Online via OneDrive or SharePoint.
   • Open or create a workbook (for example, OfficeScripts.xlsx).
   • Navigate to the Automate tab and click New Script.
   • Paste your OfficeScript code (the Mermaid diagram generator) into the script editor.
   • Save the script with a descriptive name (for instance, MermaidScript).

2. Publish the Workbook

   • Ensure that the workbook is stored on OneDrive for Business or SharePoint so that it can be accessed by Power Automate.

Configuring the Run OfficeScript Connector

Use the Run script action (from Excel Online (Business)) in Power Automate to execute your OfficeScript. Configure the connector with the following details:

• Location: OneDrive for Business (or SharePoint, if your file is hosted there).

• Document Library: Your OneDrive or SharePoint document library.

• File: Path to the Excel file containing your OfficeScript (for example, /OfficeScripts.xlsx).

• Script: Name of your script (for example, MermaidScript).

• ScriptParameters/flowJson: Directly reference the flow definition from the Get Flow as Admin connector output, like so:

   outputs('Get_Flow_as_Admin')?['body/properties/definition']
  

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Example Flow Definition

Below is a simple, generic example of a flow definition in JSON format:

{
  "$schema": "https://schema.example.com/flowdefinition.json",
  "contentVersion": "1.0.0",
  "actions": {
    "Action1": {
      "type": "InitializeVariable",
      "inputs": {
        "variables": [
          {
            "name": "Var1",
            "type": "string"
          }
        ]
      }
    },
    "Action2": {
      "runAfter": {
        "Action1": ["Succeeded"]
      },
      "type": "SetVariable",
      "inputs": {
        "name": "Var1",
        "value": "Hello World"
      }
    },
    "Condition1": {
      "type": "If",
      "runAfter": {
        "Action2": ["Succeeded"]
      },
      "actions": {
        "TrueAction": {
          "type": "Compose",
          "inputs": "True branch executed"
        }
      },
      "else": {
        "actions": {
          "FalseAction": {
            "type": "Compose",
            "inputs": "False branch executed"
          }
        }
      }
    }
  }
}

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Example Mermaid Diagram Output

When the script runs, it produces a Mermaid diagram similar to this:

---
config:
  layout: elk
---
graph TD
Start((Start))
style Start fill:#C8E6C9,stroke:#00C853,stroke-width:2px;
Start --> Action1
Action1[Action1]
class Action1 InitializeVariable;
classDef InitializeVariable fill:#FFFFFF,stroke:#000000,stroke-width:2px;
Action1 --> Action2
Action2[Action2]
class Action2 SetVariable;
classDef SetVariable fill:#FFF9C4,stroke:#FFEB3B,stroke-width:2px;
Action2 --> Condition1
subgraph "Condition1 [If Condition]"
Condition1{{Condition1}}
class Condition1 If;
Condition1 -- Yes --> TrueAction
TrueAction[TrueAction]
class TrueAction Compose;
Condition1 -- No --> FalseAction
FalseAction[FalseAction]
class FalseAction Compose;
end

You can render this output using any Mermaid-compatible tool (such as the Mermaid Live Editor) or directly in GitHub Markdown to view your flow diagram.

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Code Structure

• JSON Parsing & Validation:
  Validates the input JSON and extracts actions (even if nested).

• Global Actions Map:
  Recursively maps all actions to correctly establish dependencies.

• Mermaid Diagram Generation:
  Constructs the diagram by:

  • Defining a starting node (Start).
  • Processing each action and connecting them based on runAfter dependencies.
  • Creating subgraphs for condition (If) actions.
  • Applying custom styles based on action types.

• Logging:
  Helper functions log the processing status to aid debugging.

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Contributing

Contributions to enhance functionality or fix issues are welcome! Please open an issue or submit a pull request with your suggestions.

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Support

If you'd like to support my work: