WireHttp::sendFile() method   
Send the contents of the given filename to the current http connection.
This function utilizes the $config->fileContentTypes to match file extension
to content type headers and force-download state.
This function throws a WireException if the file can't be sent for some reason.
Usage
// basic usage
$int = $http->sendFile($filename);
// usage with all arguments
$int = $http->sendFile($filename, array $options = [], array $headers = []);Arguments
| Name | Type(s) | Description | 
|---|---|---|
| $filename | stringbool | Filename to send (or boolean false if sending $options[data] rather than file) | 
| $options(optional) | array | Options that you may pass in: 
 | 
| $headers(optional) | array | Headers that are sent. These are the defaults: 
 | 
Return value
intReturns value only if exit option is false (value is quantity of bytes sent)
Exceptions
Method can throw exceptions on error:
- WireException
Hooking $http→sendFile(…)
You can add your own hook events that are executed either before or after the $http->sendFile(…) method is executed. Examples of both are included below. A good place for hook code such as this is in your /site/ready.php file.
Hooking before
The 'before' hooks are called immediately before each $http->sendFile(…) method call is executed. This type of hook is especially useful for modifying arguments before they are sent to the method.
$this->addHookBefore('WireHttp::sendFile', function(HookEvent $event) {
  // Get the object the event occurred on, if needed
  $WireHttp = $event->object;
  // Get values of arguments sent to hook (and optionally modify them)
  $filename = $event->arguments(0);
  $options = $event->arguments(1);
  $headers = $event->arguments(2);
  /* Your code here, perhaps modifying arguments */
  // Populate back arguments (if you have modified them)
  $event->arguments(0, $filename);
  $event->arguments(1, $options);
  $event->arguments(2, $headers);
});   Hooking after
The 'after' hooks are called immediately after each $http->sendFile(…) method call is executed. This type of hook is especially useful for modifying the value that was returned by the method call.
$this->addHookAfter('WireHttp::sendFile', function(HookEvent $event) {
  // Get the object the event occurred on, if needed
  $WireHttp = $event->object;
  // An 'after' hook can retrieve and/or modify the return value
  $return = $event->return;
  // Get values of arguments sent to hook (if needed)
  $filename = $event->arguments(0);
  $options = $event->arguments(1);
  $headers = $event->arguments(2);
  /* Your code here, perhaps modifying the return value */
  // Populate back return value, if you have modified it
  $event->return = $return;
});   API reference based on ProcessWire core version 3.0.252