tao

Functional, aspect-oriented middleware for browser-side JavaScript and Node.js


Examples

Provides Middleware for Arbitrary Function Libraries

Tao is a framework for aspect-oriented programming that is meant to run
anywhere: client or server, React or Express, wherever you need
cross-cutting business logic. One mechanism Tao provides for aspect
oriented programming is middleware, or functions that run every time
you call a function in your Tao library.

``javascript

return co(function*() {
const lib = tao({
// In tao, an "action" is a function that takes one parameter and
// returns a promise
stub: () => param => Promise.resolve(param),
plusOne: () => param => Promise.resolve(param + 1)
})();

lib.use(action => {
// Prints the name of the function (action) that was called
// "stub"
// "plusOne"
console.log(action.name);
});

assert.equal(yield lib.stub(42), 42);
assert.equal(yield lib.plusOne(41), 42);
});

`

Integrates with Express


Tao is meant to be a meta-framework that lets you write business logic
in a framework-agnostic way, and then use the wrap() function to
glue your business logic to a particular framework. For example, you
can write business logic and then wrap() your functions into
Express route handlers.


`javascript

return co(function*() {
const app = express();

const lib = tao({
hello: () => params => {
return Promise.resolve(params.val || 'Hello');
}
})();

lib.wrap((lib, name) => {
const fn = get(lib, name);
return (req, res) => {
fn(Object.assign({}, req.query, req.params)).
then(val => res.send(val)).
catch(err => res.status(500).send(err.message));
};
});

app.get('*', lib.hello);

const server = app.listen(3000);

const { text } = yield superagent.get('http://localhost:3000/?val=hello');

assert.equal(text, 'hello');
});

``