.. _mac-scripting:

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MacPython OSA Modules

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This chapter describes the current implementation of the Open Scripting

Architecture (OSA, also commonly referred to as AppleScript) for Python,

allowing you to control scriptable applications from your Python program,

and with a fairly pythonic interface. Development on this set of modules has

stopped, and a replacement is expected for Python 2.5.

For a description of the various components of AppleScript and OSA, and to get

an understanding of the architecture and terminology, you should read Apple's

documentation. The "Applescript Language Guide" explains the conceptual model

and the terminology, and documents the standard suite. The "Open Scripting

Architecture" document explains how to use OSA from an application programmers

point of view. In the Apple Help Viewer these books are located in the Developer

Documentation, Core Technologies section.

As an example of scripting an application, the following piece of AppleScript

will get the name of the frontmost :program:`Finder` window and print it::

   tell application "Finder"

       get name of window 1

   end tell

In Python, the following code fragment will do the same::

   import Finder

   f = Finder.Finder()

   print f.get(f.window(1).name)

As distributed the Python library includes packages that implement the standard

suites, plus packages that interface to a small number of common applications.

To send AppleEvents to an application you must first create the Python package

interfacing to the terminology of the application (what :program:`Script Editor`

calls the "Dictionary"). This can be done from within the :program:`PythonIDE`

or by running the :file:`gensuitemodule.py` module as a standalone program from

the command line.

The generated output is a package with a number of modules, one for every suite

used in the program plus an :mod:`__init__` module to glue it all together. The

Python inheritance graph follows the AppleScript inheritance graph, so if a

program's dictionary specifies that it includes support for the Standard Suite,

but extends one or two verbs with extra arguments then the output suite will

contain a module :mod:`Standard_Suite` that imports and re-exports everything

from :mod:`StdSuites.Standard_Suite` but overrides the methods that have extra

functionality. The output of :mod:`gensuitemodule` is pretty readable, and

contains the documentation that was in the original AppleScript dictionary in

Python docstrings, so reading it is a good source of documentation.

The output package implements a main class with the same name as the package

which contains all the AppleScript verbs as methods, with the direct object as

the first argument and all optional parameters as keyword arguments. AppleScript

classes are also implemented as Python classes, as are comparisons and all the

other thingies.

The main Python class implementing the verbs also allows access to the

properties and elements declared in the AppleScript class "application". In the

current release that is as far as the object orientation goes, so in the example

above we need to use ``f.get(f.window(1).name)`` instead of the more Pythonic

``f.window(1).name.get()``.

If an AppleScript identifier is not a Python identifier the name is mangled

according to a small number of rules:

* spaces are replaced with underscores

* other non-alphanumeric characters are replaced with ``_xx_`` where ``xx`` is

  the hexadecimal character value

* any Python reserved word gets an underscore appended

Python also has support for creating scriptable applications in Python, but The

following modules are relevant to MacPython AppleScript support:

.. toctree::

   gensuitemodule.rst

   aetools.rst

   aepack.rst

   aetypes.rst

   miniaeframe.rst

In addition, support modules have been pre-generated for :mod:`Finder`,

:mod:`Terminal`, :mod:`Explorer`, :mod:`Netscape`, :mod:`CodeWarrior`,

:mod:`SystemEvents` and :mod:`StdSuites`.