pymonkey — Access SpiderMonkey from Python

This module offers a low-level interface to the Mozilla SpiderMonkey JavaScript engine.

exception pymonkey.error

This is the type of any SpiderMonkey-related errors thrown by this module.

pymonkey.undefined

This is the singleton that represents the JavaScript value undefined, as Python has no equivalent representation (JavaScript’s null is mapped to Python’s None object). For instance:

>>> cx = pymonkey.Runtime().new_context()
>>> cx.evaluate_script(cx.new_object(), '', '<string>', 1)
pymonkey.undefined

This object also has a “falsy” value:

>>> if not pymonkey.undefined:
...   print "See, it's falsy!"
See, it's falsy!

class pymonkey.Object

This is the type of JavaScript objects. Such objects can only be created via Pymonkey calls like Context.new_object() or through the execution of JS code, but this type object can be used with Python’s built-in isinstance() to verify that an object is a JS object, like so:

>>> obj = pymonkey.Runtime().new_context().new_object()
>>> isinstance(obj, pymonkey.Object)
True

class pymonkey.Context

This is the type of JavaScript context objects. Contexts can only be created via a call to Runtime.new_context(), but this type object can be used with Python’s built-in isinstance() to verify that an object is a context, like so:

>>> cx = pymonkey.Runtime().new_context()
>>> isinstance(cx, pymonkey.Context)
True

get_runtime()

Returns the Runtime that the context belongs to.

new_object()

Creates a new Object instance and returns it.

init_standard_classes(object)

Defines the standard JavaScript classes on the given Object, such as Array, eval, undefined, and so forth. For more information, see the documentation to JS_InitStandardClasses(), which this method wraps.

class pymonkey.Runtime

Creates a new JavaScript runtime. JS objects created by the runtime may only interact with other JS objects of the same runtime.

new_context()

Creates a new Context object and returns it. Contexts are best conceptualized as threads of execution in a JS runtme; each one has a program counter, a current exception state, and so forth. JS objects may be freely accessed and changed by contexts that are associated with the same JS runtime as the objects.