Flashlight

The missing Spotlight plugin system

Flashlight is an unofficial Spotlight API that allows you to programmatically process queries and add additional results. It's very rough right now, and a horrendous hack, but a fun proof of concept.

Installation

Clone and build using Xcode, or download Flashlight.app from releases.

API

The best way to get started writing a plugin is to copy an existing one and modify it. Try installing a simple plugin like 'say' or 'Pig latin,' and find it in [your-user-directory]/Library/FlashlightPlugins. Right click and 'show bundle contents,' then open the executable in a text editor. Plugins don't need to be reloaded.

Important: right now, toggling a plugin off deletes it. If the plugin's in the online directory, that isn't a big deal — if you're in the middle of writing a plugin, it is. This behavior will be fixed soon.

Flashlight plugins are .bundle files in ~/Library/FlashlightPlugins. They have a simple directory structure:

- MyPlugin.bundle
  - plugin.py 
  - examples.txt
  - Info.json
     - key 'name' (string): name of the folder, without .bundle
	  - key 'displayName' (string)
	  - key 'description' (string)
	  - key 'examples' (array of strings): usage examples

examples.txt looks like this:

weather location(brooklyn)
weather in location(new york)
how's the weather in location(queens)?
forecast for location(the bronx)
search for ~stackoverflow_query(kanye west) on stack overflow

location and ~stackoverflow_query are fields, which the parser will find for us and let us extract them later. Free-text fields, where the content of the field may be absolutely anything (and so word-frequency shouldn't be used as criteria in matching) should begin with ~.

Each line is an example of a command that will invoke this plugin. The location() identifies part of the string as a location.

When a command looks sufficiently like your examples and is routed to your plugin, Flashlight imports your plugin.py and calls results(parsed, original_query), where parsed is a dictionary containing the keys captured from the query (e.g. location). results() should return an array of (or a single) JSON dictionaries with the following keys:

• title: the title of the result
• html: optional HTML to be displayed inside the Spotlight preview
• run_args: optional if the user presses enter on your result, we'll call a function run() that you can define inside plugin.py, passing run_args as arguments. These need to be JSON-serializable.

For example, the say plugin's plugin.py looks like this:

def results(parsed, original_query):
	return {
		"title": "Say '{0}' (press enter)".format(parsed['~message']),
		"run_args": [parsed['~message']]
	}

def run(message):
	import os
	os.system('say "{0}"'.format(message))

For examples, look at the 'say' example or the Pig Latin example.

** Debugging**

Debugging support isn't the best right now — it's best to test as much of your code as possible in an ordinary Python script before running it in the plugin environment.

If Flashlight encounters an error while running your Python script, you won't see any visible error — but you'll see messages like Spotlight: querying Flashlight plugins in console.app. Expand these for a full stack trace of the error.

Please note that all Flashlight plugins currently share a 2-second quota. If you need to do costly things like network accesses, please do them in your Javascript inside the HTML you return. The weather plugin is a good example of this.

** Submitting a plugin **

Right now there isn't a fancy process for submitting. Place your plugin in PluginDirectories/$HIGHEST_NUMBER/, then run python generate_index.py. Submit a pull request.

How it works

The Flashlight.app Xcode target is a fork of EasySIMBL (which is designed to allow loading runtime injection of plugins into arbitrary apps) that's been modified to load a single plugin (stored inside its own bundle, rather than an external directory) into the Spotlight process. It should be able to coexist with EasySIMBL if you use it.

The SIMBL plugin that's loaded into Spotlight, SpotlightSIMBL.bundle, patches Spotlight to add a new subclass of SPQuery, the internal class used to fetch results from different sources. It runs a bundled Python script, which uses commanding to parse queries and determine their intents and parameters, then invokes the appropriate plugin's plugin.py script and presents the results using a custom subclass of SPResult.

Since I'm not sure how to subclass classes that aren't available at link time, subclasses of Spotlight internal classes are made at runtime using Mike Ash's instructions and helper code.

The Spotlight plugin is gated to run only on versions 911-916.1 (Yosemite GM through 10.10.1 seed). If a new version of Spotlight comes out, you can manually edit SpotlightSIMBL/SpotlightSIMBL/Info.plist key SIMBLTargetApplications.MaxBundleVersion, restarts Spotlight, verify everything works, and then submit a pull request.

Credits

The iOS-style switches in the app (ITSwitch.h/m) are ITSwitch, by Ilija Tovilo.

The code injection system is forked from [Norio Nomura](Norio Nomura)'s EasySIMBL.

Licensed under the GPL.