Plugins

See also

API Reference
More information on the Python API.
Plugins Reference
More information about plugins.

Sublime Text 2 is programmable with Python scripts. Plugins reuse existing commands or create new ones to build a feature. Plugins are rather a logical entity than a physical one.

Prerequisites

In order to write plugins, you must be able to program in Python.

Where to Store Plugins

Sublime Text 2 will look for plugins in these places:

  • Packages
  • Packages/<pkg_name>/

Consequently, any plugin nested deeper in Packages won’t be loaded.

Keeping plugins right under Packages is discouraged, because Sublime Text sorts packages in a predefined way before loading them. Thus, you might get confusing results if your plugins live outside of a package.

Your First Plugin

Let’s write a “Hello, World!” plugin for Sublime Text 2:

  1. Select Tools | New Plugin… in the menu.
  2. Save to Packages/User/hello_world.py.

You’ve just written your first plugin. Let’s put it to use:

  1. Create a new buffer (Ctrl+n).
  2. Open the python console (Ctrl+`).
  3. Type: view.run_command("example") and press enter.

You should see the text “Hello, World!” in your new buffer.

Analyzing Your First Plugin

The plugin created in the previous section should look roughly like this:

import sublime, sublime_plugin

class ExampleCommand(sublime_plugin.TextCommand):
    def run(self, edit):
        self.view.insert(edit, 0, "Hello, World!")

The sublime and sublime_plugin modules are both provided by Sublime Text 2.

New commands derive from the *Command classes defined in sublime_plugin (more on this later).

The rest of the code is concerned with particulars of the TextCommand or the API that we’ll discuss in the next sections.

Before moving on, though, we’ll look at how we called the new command: We first opened the python console, and then issued a call to view.run_command(). This is a rather inconvenient way of using plugins, but it’s often useful when you’re in the development phase. For now, keep in mind that your commands can be accessed through key bindings or other means, just as other commands are.

Conventions for Command Names

You might have noticed that our command is defined with the name ExampleCommand, but we pass the string example to the API call instead. This is necessary because Sublime Text 2 normalizes command names by stripping the Command suffix and separating CamelCasedPhrases with underscores, like this: camel_cased_phrases.

New commands should follow the pattern mentioned above for class names.

Types of Commands

You can create the following types of commands:

  • Application commands (ApplicationCommand)
  • Window commands (WindowCommand)
  • Text commands (TextCommand)

When writing plugins, consider your goal and choose the appropriate type of commands for your plugin.

Shared Traits of Commands

All commands need to implement a .run() method in order to work. Additionally, they can receive and arbitrarily long number of keyword parameters.

Application Commands

Application commands derive from sublime_plugin.ApplicationCommand. Due to the status of the API at the time of this writing, we won’t discuss application commands any further at the moment.

Window Commands

Window commands operate at the window level. This doesn’t mean that you cannot manipulate views from window commands, but rather that you don’t need views to exist in order for window commands to be available. For instance, the built-in command new_file is defined as a WindowCommand so it works too when no view is open. Requiring a view to exisit in that case wouln’t make sense.

Window command instances have a .window attribute pointing to the window instance that created them.

Text Commands

Text commands operate at the buffer level and they require a buffer to exist in order to be available.

View command instances have a .view attribute pointing to the view instance that created them.

Text Commands and the edit Object

The edit object groups modifications to the view so undo and macros work in a sensible way. You are responsible for creating and closing edit objects. To do so, you can call view.begin_edit() and edit.end_edit(). Text commands get passed an open edit object in their run method for convenience. Additionally, many View methods require an edit object.

Responding to Events

Any command deriving from EventListener will be able to respond to events.

Another Plugin Example: Feeding the Completions List

Let’s create a plugin that fetches data from Google Autocomplete service and feeds it to Sublime Text 2 completions list. Please note that as ideas for plugins go, this a very bad one.

import sublime, sublime_plugin

from xml.etree import ElementTree as ET
from urllib import urlopen

GOOGLE_AC = r"http://google.com/complete/search?output=toolbar&q=%s"

class GoogleAutocomplete(sublime_plugin.EventListener):
    def on_query_completions(self, view, prefix, locations):
        elements = ET.parse(
                        urlopen(GOOGLE_AC % prefix)
                    ).getroot().findall("./CompleteSuggestion/suggestion")

        sugs = [(x.attrib["data"],) * 2 for x in elements]

        return sugs

Note

Please make sure you don’t keep this plugin around after trying it. It will interefere with the autocompletions look-up chain.

Learning the API

In order to create plugins, you need to get acquainted with the Python API Sublime Text 2 exposes, and the available commands. Documentation on both is scarce at the time of this writing, but you can read existing code and learn from it too. In particular, the Packages/Default folder contains many examples of undocumented commands and API calls.