# reqwest.multipart

## Function

Set the multipart/form-data request body for submitting ordinary fields and file fields.

## Syntax

```bt
reqwest(url).multipart(values)
```

## Parameters

| Parameters | Type | Required | Default value | Description |
| ------ | ------ | ------ | ------ | ------ |
| values | Object | Yes | None | A multipart field mapping object; rules for keys and values are given below. |

## values object structure

| key | value type | description |
| ------ | ------ | ------ |
| Field name | Any | Ordinary field, it will be converted into a string when called. |
| Field name | Object | File field; path must be provided in the object, file_name, mime are optional. |

## File field object structure

| Field | Type | Required | Default value | Description |
| ------ | ------ | ------ | ------ | ------ |
| path | String | Yes | None | The local file path to upload. |
| file_name | String | No | Original file name | The file name exposed to the server when uploading. |
| mime | String | No | Automatically identify | file MIME type, for example `image/png`. |

## Return value

| Type | Description |
| ------ | ------ |
| Reqwest | Returns the new request builder. |

## Example

```bt
request = reqwest('https://example.com/upload').method('POST').multipart({
	name: 'BT',
	file: {path: 'demo.txt', file_name: 'demo.txt', mime: 'text/plain'}
})
result = type(request)

// Output: Reqwest
print result
```

## Notes

- values must be objects, otherwise an error will be reported.
- Body, json, form, and multipart will all set the request body; the last request body set in the same request will take effect.