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# canResumeDownloadDecoded(withEncodingMIMEType:)

Returns whether a URL download object can resume a download that was decoded with the specified MIME type.

```
class func canResumeDownloadDecoded(withEncodingMIMEType MIMEType: String) -> Bool
```

## Parameters

`MIMEType`

The MIME type the caller wants to know about.

## Return Value

<doc://com.apple.documentation/documentation/Swift/true> if the URL download object can resume a download that was decoded with the specified MIME type, <doc://com.apple.documentation/documentation/Swift/false> otherwise.

## Discussion

The MIME type of a file, in conjunction with the value returned by the [`download(_:shouldDecodeSourceDataOfMIMEType:)`](/documentation/Foundation/NSURLDownloadDelegate/download(_:shouldDecodeSourceDataOfMIMEType:)) delegate method, determines whether the `NSURLDownload` class should decode or decompress the incoming data as it is received.

Some compression techniques, such as the `DEFLATE` algorithm (`gzip`) use symbol dictionaries that vary during the compression process, making it impractical to decompress only a portion of the data starting in the middle. For this reason, this method returns <doc://com.apple.documentation/documentation/Swift/false> unless both of the following conditions are met:

- The MIME type is of a type that the `NSURLDownload` class knows how to decompress or decode.
- The decoding can be safely resumed.

In practice, this method returns <doc://com.apple.documentation/documentation/Swift/true> for MacBinary and BinHex, otherwise <doc://com.apple.documentation/documentation/Swift/false>.

If your app needs to be able to resume file downloads in `gzip` format, your [`download(_:shouldDecodeSourceDataOfMIMEType:)`](/documentation/Foundation/NSURLDownloadDelegate/download(_:shouldDecodeSourceDataOfMIMEType:)) method must return <doc://com.apple.documentation/documentation/Swift/false>, and you must decode the resulting file yourself after you finish downloading it in its entirety.

---

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