> ## Documentation Index
> Fetch the complete documentation index at: https://flatfileinc-feat-updatereactquickstart.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# @flatfile/plugin-autocast

> A plugin for automatically casting values in Flatfile.

<CardGroup cols={1}>
  <Card title="@flatfile/plugin-autocast" icon="download">
    <br />

    The `@flatfile/plugin-autocast` plugin is an opinionated transformer that will
    automatically convert the data in the Sheet to match the type defined by the
    Blueprint.

    <br />

    <br />

    **Event Type:**

    <br />

    `listener.on('commit:created')`

    <br />

    **Supported field types:**<br />`number`, `boolean`, `date`
  </Card>
</CardGroup>

## Parameters

<ParamField path="sheetSlug" type="string" required>
  The `sheetSlug` indicates the slug name of the sheet you want to monitor.
</ParamField>

<ParamField path="fieldFilters" type="string[]">
  Use the `fieldFilters` parameter to select specific fields to monitor. Without
  any specified `fieldFilters`, the plugin will automatically monitor
  castable-field (number, boolean & Date).
</ParamField>

<ParamField path="options.chunkSize" default="10_000" type="number" optional>
  The `chunkSize` parameter allows you to specify the quantity of records to in
  each chunk.
</ParamField>

<ParamField path="options.parallel" default="1" type="number" optional>
  The `parallel` parameter allows you to specify the number of chunks to process
  in parallel.
</ParamField>

## API Calls

* `api.sheets.get`

## Imported NPM Packages

* [`@flatfile/api@1.7.4+`](https://www.npmjs.com/package/@flatfile/api)
* [`@flatfile/listener@1.0.1+`](https://www.npmjs.com/package/@flatfile/listener)
* [`@flatfile/plugin-record-hook@1.4.4+`](./record-hook)
* `@flatfile/util-common@1.0.0+`

## Usage

The `autocast` plugin will listen for the `commit:created` event and cast numbers, booleans,
and dates to the appropriate Blueprint type. Note that the `recordHook` and `bulkRecordHook` plugins
listen for the same event type. Plugins will fire in the order they are placed in the listener.

### Strings

Numbers and booleans are cast to strings (i.e `'1'` -> `1`, `true` -> `"true"`).

### Numbers

String numbers (i.e `'1'`), string decimals (i.e `'1.1'`), and string numbers with commas (i.e `'1,000'`)
are interpreted as numbers.

### Booleans

`'1'`, `'yes'`, `'true'`, `'on'`, `'t'`, `'y'`, and `1` are interpreted as truthy values.

`'-1'`, `'0'`, `'no'`, `'false'`, `'off'`, `'f'`, `'n'`, `0`, `-1` are interpreted as falsy values.

### Dates

Date strings and numbers are cast to a UTC string. These are example of dates that will be cast (note: `YYYY-MM-DD...` is interpreted as an ISO 8601 date and is treated as treated as UTC, while other formats are treated as local time and converted to UTC):

* `'2023-08-16'` => `'Wed, 16 Aug 2023 00:00:00 GMT'`
* `'08-16-2023'` => `'Wed, 16 Aug 2023 00:00:00 GMT'`
* `'08/16/2023'` => `'Wed, 16 Aug 2023 00:00:00 GMT'`
* `'Aug 16, 2023'` => `'Wed, 16 Aug 2023 00:00:00 GMT'`
* `'August 16, 2023'` => `'Wed, 16 Aug 2023 00:00:00 GMT'`
* `'2023-08-16T00:00:00.000Z'` => `'Wed, 16 Aug 2023 00:00:00 GMT'`
* `1692144000000` => `'Wed, 16 Aug 2023 00:00:00 GMT'`

```bash install
npm i @flatfile/plugin-autocast
```

```js import
import { autocast } from "@flatfile/plugin-autocast";
```

<CodeGroup>
  ```js listener.js
  listener.use(autocast("sheetSlug"));
  ```

  ```js listener.js w/ fieldFilters
  listener.use(autocast("sheetSlug", ["numberField", "dateField"]));
  ```

  ```js listener.js w/ fieldFilters & options
  listener.use(
    autocast("sheetSlug", ["numberField", "dateField"], {
      chunkSize: 10_000,
      parallel: 2,
    })
  );
  ```
</CodeGroup>

## See the code

<CardGroup cols={2}>
  <Card title="@flatfile/plugin-autocast" href="https://github.com/FlatFilers/flatfile-plugins/tree/main/plugins/autocast" icon="github" />
</CardGroup>