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https://github.com/phith0n/pyduktape2

Embed the Duktape JS interpreter in Python, forking and develop based on https://github.com/stefano/pyduktape
https://github.com/phith0n/pyduktape2

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Embed the Duktape JS interpreter in Python, forking and develop based on https://github.com/stefano/pyduktape

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README 

        
Introduction

############



Pyduktape is a python wrapper around `Duktape `_,

an embeddable Javascript interpreter.



On top of the interpreter wrapper, pyduktape offers easy integration

between the Python and the Javascript environments. You can pass

Python objects to Javascript, call methods on them and access their

attributes.  Similarly, you can pass Javascript objects to Python.



Objects are never copied or serialized. Instead, they are passed

between the two environments using proxy objects. Proxy objects

delegate the execution to the original object environment.



Threading

#########



It is possible to invoke Javascript code from multiple threads. Each

thread will need to use its own embedded interpreter. Javascript

objects returned to the Python environment will only be usable on the

same thread that created them. The runtime always checks this

condition automatically, and raises a ``DuktapeThreadError`` if it's

violated.



Getting Started

###############



Installation

------------



To install from pypi::



    $ pip install pyduktape2



To install the latest version from github::



    $ pip install git+https://github.com/phith0n/pyduktape2



Running Javascript code

-----------------------



To run Javascript code, you need to create an execution context and

use the method ``eval_js``::



    import pyduktape2



    context = pyduktape2.DuktapeContext()

    context.eval_js("print(Duktape.version);")



Each execution context starts its own interpreter. Each context is

independent, and tied to the Python thread that created it. Memory is

automatically managed.



To evaluate external Javascript files, use ``eval_js_file``::



    // helloWorld.js

    print('Hello, World!');



    # in the Python interpreter

    import pyduktape2



    context = pyduktape2.DuktapeContext()

    context.eval_js_file('helloWorld.js')



Pyduktape supports Javascript modules::



    // js/helloWorld.js

    exports.sayHello = function () {

        print('Hello, World!');

    };



    // js/main.js

    var helloWorld = require('js/helloWorld');

    helloWorld.sayHello();



    # in the Python interpreter

    import pyduktape2



    context = pyduktape2.DuktapeContext()

    context.eval_js_file('js/main')



The ``.js`` extension is automatically added if missing.  Relative

paths are relative to the current working directory, but you can

change the base path using ``set_base_path``::



    # js/helloWorld.js

    print('Hello, World!');



    # in the Python interpreter

    import pyduktape2



    context = pyduktape2.DuktapeContext()

    context.set_base_path('js')

    context.eval_js_file('helloWorld')



Python and Javascript integration

---------------------------------



You can use ``set_globals`` to set Javascript global variables::



    import pyduktape2



    def say_hello(to):

        print 'Hello, {}!'.format(to)



    context = pyduktape2.DuktapeContext()

    context.set_globals(sayHello=say_hello, world='World')

    context.eval_js("sayHello(world);")



You can use ``get_global`` to access Javascript global variables::



    import pyduktape2



    context = pyduktape2.DuktapeContext()

    context.eval_js("var helloWorld = 'Hello, World!';")

    print context.get_global('helloWorld')



``eval_js`` returns the value of the last expression::



    import pyduktape2



    context = pyduktape2.DuktapeContext()

    hello_world = context.eval_js("var helloWorld = 'Hello, World!'; helloWorld")

    print hello_world



You can seamlessly use Python objects and functions within Javascript

code.  There are some limitations, though: any Python callable can

only be used as a function, and other attributes cannot be

accessed. Primitive types (int, float, string, None) are converted to

equivalent Javascript primitives.  The following code shows how to

interact with a Python object from Javascript::



    import pyduktape2



    class Hello(object):

        def __init__(self, what):

            self.what = what



        def say(self):

            print('Hello, {}!'.format(self.what))



    context = pyduktape2.DuktapeContext()

    context.set_globals(Hello=Hello)

    context.eval_js("var helloWorld = Hello('World'); helloWorld.say();")



In the same way, you can use Javascript objects in Python.  You can

use the special method `new` to instantiate an object::



    import pyduktape2



    context = pyduktape2.DuktapeContext()

    Hello = context.eval_js("""

    function Hello(what) {

        this.what = what;

    }



    Hello.prototype.say = function () {

        print('Hello, ' + this.what + '!');

    };



    Hello

    """)



    hello_world = Hello.new('World')

    hello_world.say()



You can use Python lists and dicts from Javascript, and viceversa::



    import pyduktape2



    context = pyduktape2.DuktapeContext()

    res = context.eval_js('[1, 2, 3]')



    for item in res:

        print(item)



    context.set_globals(lst=[4, 5, 6])

    context.eval_js('for (var i = 0; i < lst.length; i++) { print(lst[i]); }')



    res = context.eval_js('var x = {a: 1, b: 2}; x')

    for key, val in res.items():

        print(key, '=', val)

    res.c = 3

    context.eval_js('print(x.c);')



    context.set_globals(x=dict(a=1, b=2))

    context.eval_js("""

    var items = x.items();

    for (var i = 0; i < items.length; i++) {

        print(items[i][0] + ' = ' + items[i][1]);

    }

    """)

    context.set_globals(x=dict(a=1, b=2))

    context.eval_js('for (var k in x) { print(k + ' = ' + x[k]); }')