AspectJS

Supporting AOP in JavaScript.

Installation

Node.JS

var aspect = require('aspect-js');

Browser

Import by <script> tag. aspect is then attached to window.

<script src="path/to/aspect-js.js"></script>
<script>
    aspect.before(...);
</script>

APIs

aspect.before(context, method, advice)

Run advice before the execution of method of context.

e.g.:

// In browser.
var getName = function (id) {
    return id + ': Example';
}

aspect.before(this, 'getName', function (id) {
    console.log('Getting name of ' + id + ' now...');
});

aspect.after(context, method, advice)

Run advice after the execution of method of context no matter if method is returned normally or has thrown an exception.

e.g.:

// In browser.
var test = function (name, age) {
    console.log('Hi, ' + name);
    if (age > 26) {
        throw new Error('Big age :-)');
    }
    return '[' + age + ']';
};

aspect.after(this, "test", function (data, name, age) {
    console.log('Process returned: ' + data)
});

aspect.afterReturn(context, method, advice)

Run advice after the execution of method of context only if method is returned normally.

e.g.:

// In browser.
var test = function (name, age) {
    console.log('Hi, ' + name);
    if (age > 26) {
        throw new Error('Big age :-)');
    }
    return '[' + age + ']';
};

aspect.afterReturn(this, "test", function (data, name) {
    console.log('Process returned: ' + data)
});

aspect.afterThrow(context, method, advice)

Run advice after the execution of method of context only if method has thrown an exception.

e.g.:

// In browser.
var test = function (name, age) {
    console.log('Hi, ' + name);
    if (age > 26) {
        throw new Error('Big age :-)');
    }
    return '[' + age + ']';
};

aspect.afterThrow(this, "test", function (err, name) {
    console.log('Test has thrown: ' + err.message);
});

aspect.around(context, method, advice)

Surrounds method of context with advice.

advice will automatically received a copy of the original function as its first parameter.

e.g.:

// In browser.
var test = function (name, age) {
    console.log('Hi, ' + name);
    if (age > 26) {
        throw new Error('Big age :-)');
    }
    return '[' + age + ']';
};

aspect.around(this, "test", function (orig, name, age) {
    console.log('====================');
    orig(name, age);
    console.log('====================');
});

License

MIT