Triggering flows from portal forms

Power Pages (formerly Power Apps Portals) allows you to build secure, data-driven websites that can interact with Microsoft Dataverse and external systems. One of the most powerful ways to extend its capabilities is by triggering Power Automate flows when a user submits a form. This integration automates workflows such as sending emails, processing approvals, updating other systems, and more.

This detailed guide explains how to trigger flows from portal forms step by step.

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Why Trigger Flows from Portal Forms?

Triggering flows on form submissions helps you:

• Send real-time notifications to stakeholders
• Update or sync data in external systems
• Perform background calculations or processes
• Log form activity for audit or analytics
• Start approval workflows

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Available Trigger Options

There are three primary ways to trigger a Power Automate flow from a portal form:

1. When a Dataverse record is created or modified
2. Using JavaScript to call a flow via HTTP
3. Using Webhooks or Custom APIs (advanced)

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Approach 1: Triggering via Dataverse (Most Common)

Use Case: You have a form that creates or updates a Dataverse record (via Entity/Form in Power Pages)

Step-by-Step:

1. Create the Portal Form

• Go to Power Pages Studio
• Add an Entity Form (now called Basic Form) tied to a Dataverse table
• Set it to create or update mode

Example: A Contact Us form that saves data in a Contact Requests table

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2. Create a Power Automate Flow

• Open Power Automate (https://make.powerautomate.com)
• Create a new Automated Cloud Flow
• Trigger: When a row is added, modified, or deleted (Dataverse)
• Choose:
  • Change Type: Create
  • Table: Contact Requests (or your custom table)
  • Scope: Organization

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3. Add Actions in the Flow

• Use Get row by ID if you need more data
• Send email, update records, call APIs, etc.

Example:
- Get row details
- Send a confirmation email to user
- Notify admin team in Teams

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4. Save and Test

• Submit the form on the portal
• Verify that the flow gets triggered and performs expected actions

Pros:

• Secure (no direct API tokens)
• Easy to manage in low-code
• Works automatically with table-bound forms

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Approach 2: Triggering Flow from Portal via HTTP Request (JavaScript)

Best for custom logic or unbound forms where you want to manually call a Power Automate flow.

Step-by-Step:

1. Create a Power Automate Flow with HTTP Trigger

• Trigger: When an HTTP request is received
• Design your logic
• End with a Response action to return data to the portal

{
  "firstName": "string",
  "email": "string",
  "message": "string"
}

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2. Copy the HTTP POST URL

• Save and copy the automatically generated endpoint

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3. Add JavaScript in Your Web Page or Web Template

<script>
function submitToFlow() {
  const payload = {
    firstName: document.getElementById("fname").value,
    email: document.getElementById("email").value,
    message: document.getElementById("msg").value
  };

  fetch("https://prod-00.westus.logic.azure.com:443/workflows/...", {
    method: "POST",
    headers: {
      "Content-Type": "application/json"
    },
    body: JSON.stringify(payload)
  })
  .then(response => response.json())
  .then(data => {
    alert("Submitted successfully!");
  })
  .catch(err => {
    console.error("Flow error:", err);
  });
}
</script>

Add the above function call to your custom form’s submit button.

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4. Secure the Flow

• Restrict access using Azure API Management or a Gateway
• Or add an API key header for authentication

Avoid putting secrets in frontend JS

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Approach 3: Using Webhooks or Custom APIs (Advanced)

Advanced scenarios might require:

• Custom Dataverse plugins that invoke flows or APIs
• Azure Functions triggered from Power Pages
• Custom web services that are called from Power Automate and handle more logic

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Best Practices

Practice	Recommendation
Security	Never expose secrets in frontend code
Validation	Validate form inputs before sending to Flow
Error Handling	Add try/catch logic in Flow and frontend
Testing	Always test with sample data and debug responses
Logging	Log submissions in Dataverse or use telemetry

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Common Use Cases

• Contact or inquiry forms that notify sales team
• Feedback forms that create a case record
• Job application forms that start HR workflows
• Custom forms that interact with SharePoint, Outlook, Teams, etc.
• Form submissions that trigger approval processes