The Record Hook plugin provides a way to execute custom logic on individual data records within a Flatfile Sheet. It works by attaching a listener to the commit:created event, which fires when new data is added or existing data is updated. This plugin is ideal for a variety of use cases, including:
  • Data Validation: Implementing complex validation rules that go beyond Flatfile’s built-in validators, such as checking for valid email formats or ensuring conditional field requirements.
  • Data Transformation: Modifying data on the fly, like capitalizing names, standardizing formats, or setting default values.
  • Data Enrichment: Augmenting records with additional information from external sources.
  • Data Cleaning: Removing whitespace, correcting common typos, or normalizing values.
The plugin offers two main functions: recordHook for processing records one-by-one, and bulkRecordHook for processing records in batches, which is more efficient for large datasets.

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Installation

Install the plugin using npm: 
npm install @flatfile/plugin-record-hook

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Configuration & Parameters

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recordHook

Processes individual records one at a time. The provided callback function is executed for each record in the commit. Parameters:
  • sheetSlug (string, required): The slug of the Sheet you want the hook to apply to
  • callback (function, required): A function that contains your custom logic. It receives the record and the event object as arguments
  • options (object, optional): Configuration options
    • concurrency (number, default: 10): Controls how many individual record handlers can run in parallel
    • debug (boolean, default: false): When set to true, enables verbose logging to the console

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bulkRecordHook

Processes records in batches (chunks). The provided callback function is executed for each chunk of records. Parameters:
  • sheetSlug (string, required): The slug of the Sheet you want the hook to apply to
  • callback (function, required): A function that contains your custom logic. It receives an array of records and the event object as arguments
  • options (object, optional): Configuration options
    • chunkSize (number, default: 10000): Specifies the number of records to process in each batch. Maximum recommended value is 5000
    • parallel (number, default: 1): Specifies how many chunks of records to process in parallel
    • debug (boolean, default: false): When set to true, enables verbose logging to the console
Default Behavior: By default, the plugin processes records for the specified sheetSlug after a commit is created. bulkRecordHook processes all records in a single chunk sequentially (parallel: 1). recordHook processes up to 10 records concurrently. Debug logging is disabled.

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Usage Examples

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Basic Single Record Processing

import { recordHook } from "@flatfile/plugin-record-hook";
import { FlatfileListener } from "@flatfile/listener";

export default function (listener) {
  listener.use(
    recordHook("contacts", (record) => {
      const firstName = record.get("firstName");
      if (firstName) {
        record.set("firstName", firstName.charAt(0).toUpperCase() + firstName.slice(1));
      }
      return record;
    })
  );
}

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Basic Bulk Record Processing

import { bulkRecordHook } from "@flatfile/plugin-record-hook";
import { FlatfileListener } from "@flatfile/listener";

export default function (listener) {
  listener.use(
    bulkRecordHook("contacts", (records) => {
      records.forEach((record) => {
        const firstName = record.get("firstName");
        if (firstName) {
          record.set("firstName", firstName.charAt(0).toUpperCase() + firstName.slice(1));
        }
      });
      return records;
    })
  );
}

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Configuration Example

import { bulkRecordHook } from "@flatfile/plugin-record-hook";
import { FlatfileListener } from "@flatfile/listener";

export default function (listener) {
  listener.use(
    bulkRecordHook(
      "contacts",
      (records) => {
        // Your processing logic here
        return records;
      },
      { chunkSize: 1000, parallel: 5, debug: true }
    )
  );
}

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Advanced Usage - Email Validation

import { recordHook } from "@flatfile/plugin-record-hook";
import { FlatfileListener } from "@flatfile/listener";

export default function (listener) {
  listener.use(
    recordHook("contacts", (record) => {
      const email = record.get("email");
      if (!email) {
        record.addError("email", "Email address is required.");
        return record;
      }

      const validEmailRegex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
      if (!validEmailRegex.test(email)) {
        record.addError("email", "Please enter a valid email address.");
      }
      return record;
    })
  );
}

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Troubleshooting

The most effective way to troubleshoot issues is to set the debug: true option in the plugin configuration. This will print detailed logs to the console, showing the timing and status of each major step: fetching data, running the handler, filtering modified records, and updating records. This can help identify performance bottlenecks or see why records are not being updated as expected.

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Notes

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Special Considerations

  • The plugin operates on the commit:created event. This means it runs after Flatfile’s initial parsing and validation but before the data is finalized.
  • To save changes, your callback function must return the modified record (for recordHook) or the array of modified records (for bulkRecordHook). If you return null, undefined, or nothing, your changes will not be persisted.
  • The plugin intelligently detects which records have actually been modified and only sends those records back to the Flatfile API for an update, optimizing performance.

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Limitations

  • The chunkSize for bulkRecordHook has a recommended maximum of 5000 records to ensure stability and performance.

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Error Handling

  • The plugin is designed to be robust. It wraps the execution of the user-provided callback in a try...catch block.
  • If an error is thrown inside your callback, the plugin will log the error message to the console with a [FATAL] prefix.
  • Crucially, it will then ensure the commit is marked as complete with the Flatfile API, preventing the import process from stalling due to an error in custom code.