sendContentAsFile() public method
Sends the specified content as a file to the browser. Note that this method only prepares the response for file sending. The file is not sent until send() is called explicitly or implicitly. The latter is done after you return from a controller action. See also sendFile() for an example implementation.
public $this sendContentAsFile ( $content, $attachmentName, $options = [] )$content string
The content to be sent. The existing $content will be discarded