How can I map webhook form IDs to text outputs in n8n using a match table?

Below is one way to do this in n8n:

1. Webhook Trigger
   Start your workflow with a Webhook node that receives the Meta ADS webhook. Make sure the webhook’s payload (for example, the form ID) is part of the JSON data.

2. Determine the Output Using a Switch or Function Node

   You have two main options:

   A. Using a Switch Node:
   • Add a Switch node right after the Webhook node.
   • In the Switch node’s settings, define conditions that compare the form ID field. For example:

   • If the value (e.g. {{$json["formId"]}}) equals 1234 → route to one branch.
   • If it equals 2345 → route to another branch.
   • If it equals 3456 → route to a third branch.

   • In each branch (or subsequent Set node), add a Set node to assign the desired text output (e.g. “It’s a doctor's form”) to a new or existing field.

   B. Using a Function Node with a Mapping Object:
   • Insert a Function node after your Webhook node.
   • In the Function node, create a JavaScript object that maps form ID values to their respective text outputs.

   Here’s an example code snippet:

   JAVASCRIPTCopied
   // Get the formId from the incoming webhook data
   const formId = $json.formId;
   
   // Create a mapping table
   const formMapping = {
     "1234": "It's a doctor's form",
     "2345": "It's a nurse's form",
     "3456": "It's a lawyer's form"
   };
   
   // Set the output text based on the formId
   // If formId is not found, you can set a default value.
   $json.formText = formMapping[formId] || "Unknown form";
   
   return $json;

   • The Function node will add a new property (in this example, formText) containing the output text.
   • You can then continue your workflow using this field as needed.

3. Use the Output Data
   The result from either approach can be used in further steps of your workflow, whether for logging, notifications, or any other processing.

Choose the approach that best fits your use case. The Switch node is great for visual routing if you have only a few cases, while the Function node with a mapping table is more scalable if you plan to have many form IDs.

Remember to test using your webhook’s test URL before switching to production.