The simplest possible IDA plugin with multiple actions

hello_world_plugin.py

##############################################################################
#
# Name: hello_world_plugin.py
# Auth: @cmatthewbrooks
# Desc: A test plugin to learn how to make these work; Specifically, how to
#       have multiple actions within the same plugin.
#
#       In plain English, IDA will look for the PLUGIN_ENTRY function which
#       should return a plugin object. This object can contain all the 
#       functionality itself, or it can have multiple actions.
#
#       To register actions, use the idaaapi.register_action() function with
#       an argument of type idaapi.action_desc_t.
#
#       A helpful hint from IDA support, don't register actions inside the
#       Edit/Plugins sub-menu. It's dynamic and can be wiped out and built
#       within a session. It's better to register actions' menu locations
#       elsewhere.
#
#
# With help from:
# 
# http://www.hexblog.com/?p=886
# https://github.com/fireeye/flare-ida/blob/master/plugins/
# https://github.com/mwrlabs/win_driver_plugin/
#
##############################################################################



import idaapi



# Define callbacks which are the actions I actually
# want to perform

def hello_mars():

    print('Hello Mars!')

def hello_earth():

    print('Hello Earth!')


# Define the action_handler_t object that fires the
# callback function when each action is activated

class ActionHandler(idaapi.action_handler_t):

    def __init__(self, callback):
        
        idaapi.action_handler_t.__init__(self)
        self.callback = callback
    
    def activate(self, ctx):

        self.callback()
        return 1

    def update(self, ctx):
        
        return idaapi.AST_ENABLE_ALWAYS


# Define a method to register all the actions when
# the plugin is initialized

def register_actions():   

    actions = [
        {
            'id': 'hello:earth',
            'name': 'Hello Earth',
            'hotkey': 'Ctrl+Alt+E',
            'comment': 'Print Hello Earth',
            'callback': hello_earth,
            'menu_location': 'Edit/Hello World/Hello Earth'
        },
        {
            'id': 'hello:mars',
            'name': 'Hello Mars',
            'hotkey': 'Ctrl+Alt+M',
            'comment': 'Print Hello Mars',
            'callback': hello_mars,
            'menu_location': 'Edit/Hello World/Hello Mars'
        }
    ]


    for action in actions:

        if not idaapi.register_action(idaapi.action_desc_t(
            action['id'], # Must be the unique item
            action['name'], # The name the user sees
            ActionHandler(action['callback']), # The function to call
            action['hotkey'], # A shortcut, if any (optional)
            action['comment'] # A comment, if any (optional)
        )):

            print('Failed to register ' + action['id'])

        if not idaapi.attach_action_to_menu(
            action['menu_location'], # The menu location
            action['id'], # The unique function ID
            0):

            print('Failed to attach to menu '+ action['id'])


# Define the plugin class itself which is returned by
# the PLUGIN_ENTRY method that scriptable plugins use
# to be recognized within IDA

class HelloWorldPlugin(idaapi.plugin_t):

    # Use the HIDE flag to avoid the entry in 
    # Edit/Plugins since this plugin's run() 
    # method has no functionality...it's all 
    # in the actions.

    flags = idaapi.PLUGIN_HIDE
    comment = 'A test plugin'
    help = 'No help - this is just a test'
    wanted_name = 'Hello World'
    wanted_hotkey = ''

    def init(self):
        print('HelloWorldPlugin init')
        
        register_actions()

        # Return KEEP instead of OK to keep the
        # plugin loaded since it registers
        # callback actions and hotkeys
        #
        # Use OK if the functionality is 
        # all in the plugin and it does
        # one thing then completes.
        return idaapi.PLUGIN_KEEP

    def run(self, arg):
        print('HelloWorldPlugin run')

    def term(self):
        print('HelloWorldPlugin term')


# The PLUGIN_ENTRY method is what IDA calls when
# scriptable plugins are loaded. It needs to
# return a plugin of type idaapi.plugin_t

def PLUGIN_ENTRY():
    
    try:
        return HelloWorldPlugin()
    
    except Exception, err:
        import traceback
        print('Error: %s\n%s' % str((err), traceback.format_exc()))
        raise