# Hotplug : Hotplug event management

This module provides hotplug listening service.

User can use the following code to import the Hotplug module.

var Hotplug = require('hotplug');

# Support

The following shows Hotplug module APIs available for each permissions.

# Hotplug Class

# new Hotplug()

• Returns: {Object} Returns hotplug object.

Create a hotplug event listener.

# Example

var hotplug = new Hotplug();

# Hotplug.open()

• Returns: {Object} Returns hotplug object.

Same as new Hotplug(), but returns undefined with no exception.

# Hotplug Object

The hotplug object inherits from EventEmitter, and the on() method can be used to add processing callbacks for different events.

# hotplug.close()

Close this hotplug and reclaiming file descriptors. Due to the addition of asynchronous events, you must call this function manually when this object is no longer used.

# hotplug.clear()

Clear all unreceived event information.

# Example

var hotplug = Hotplug.open();
hotplug.clear();

# Hotplug Events

The Hotplug class inherits from the EventEmitter class. The following events are thrown in some specific situations.

# insert

This event occurs when the system has a device plugged in and correctly recognized, such as inserting a USB disk, SD/MMC card, etc.

# Example

hotplug.on('insert', function(path, type) {
  // new device add
});

# remove

In contrast to the 'insert' event, this event is generated when the device is unplugged.

# Example

hotplug.on('remove', function(path, type) {
  // device removed
});

# all

This event is generated for all hotplug.

# Example

hotplug.on('all', function(isInsert, path, type) {
  if (isInsert) {
    // new device add
  } else {
    // device removed
  }
});

# error

If an error occured an error event is emitted with the error information. System will automatically call hotplug.close() later.

# Example

hotplug.on('error', function(error) {
  // check error information
});