> ## Documentation Index
> Fetch the complete documentation index at: https://developer.dromo.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Processing Import Results in Your Application

> Process completed Dromo import data and metadata in the browser, send results to your backend, or receive them through webhooks.

<Info>
  For more information on the onResults callback, see the [Reference](/reference/results#the-onresults-callback) documentation.
</Info>

Here we show how to handle results directly in the browser, using Google Firebase as an example (unlike an RDBMS like Postgres, Firebase allows for direct browser connections). To handle results on a server, either send the `onResults` data to an API you control or subscribe to a [webhook](/reference/webhooks).

This example assumes you have installed the [Firebase SDK](https://firebase.google.com/docs/web/setup).

<CodeGroup>
  ```javascript theme={null}
  import { initializeApp } from 'firebase/app';
  import { getFirestore } from 'firebase/firestore';
  import { addDoc, collection } from 'firebase/firestore';

  const firebaseConfig = {
    ...
  };

  const app = initializeApp(firebaseConfig);
  const db = getFirestore(app);

  ```
</CodeGroup>

The `onResults` callback returns an array of objects, where each object represents a record. The callback also receives a `metadata` object containing information about the import process.

<CodeGroup>
  ```javascript theme={null}
  dromo.onResults(function (data, metadata) {
    console.log('Import metadata:', metadata);

    // Loop through each item in the data array and add it as a document in Firebase
    data.forEach(async (record) => {
      try {
        const docRef = await addDoc(collection(db, 'collectionName'), record);
        console.log(`Document written with ID: ${docRef.id}`);
      } catch (e) {
        console.error('Error adding document: ', e);
      }
    })
  });
  ```
</CodeGroup>

## Working with Metadata

The `metadata` object contains useful information about the import:

```javascript theme={null}
dromo.onResults(function (data, metadata) {
  console.log('Total rows processed:', metadata.totalRows);
  console.log('Valid rows:', metadata.validRows);
  console.log('Invalid rows:', metadata.invalidRows);
  console.log('Original headers:', metadata.rawHeaders);
});
```

## Handling Unmapped Columns

If you've enabled the `passThroughUnmappedColumns` setting, your data will include unmapped columns that weren't part of your schema:

```javascript theme={null}
dromo.onResults(function (data, metadata) {
  data.forEach(async (record) => {
    // Process main mapped data
    const mappedData = { ...record };
    delete mappedData.$unmapped;

    // Handle unmapped columns separately if they exist
    if (record.$unmapped && metadata.rawHeaders) {
      const unmappedData = {};
      Object.entries(record.$unmapped).forEach(([index, value]) => {
        const headerName = metadata.rawHeaders[parseInt(index)];
        if (headerName) {
          unmappedData[headerName] = value;
        }
      });

      // Store unmapped data in a separate collection or field
      console.log('Unmapped data:', unmappedData);
    }

    // Save to Firebase
    await addDoc(collection(db, 'collectionName'), mappedData);
  });
});
```

<Note>
  For a comprehensive guide on working with unmapped columns, see the [Accessing Unmapped Columns guide](/guides/accessing-unmapped-columns).
</Note>