@ekolabs/iframily

Iframily

Iframily is a small javascript library that simplifies communication between frames.

This is how it works:

1. Create iframilies in the parent frame.
2. Create iframilies in the child frame.
3. If a parent id and child id match, they will pair.
4. Send messages between paired iframilies.

Features

• Works with cross domain IFrames.
• Send any serializable message.
• Support sync and async responses (Promise based).
• Queue messages sent until pairing has completed.

How do I get set up

npm i @ekolabs/iframily --save

You can also add the library via script tag and use window.Iframily, like so:

<script src="https://unpkg.com/@ekolabs/iframily"></script>

API

--- Iframily singleton ---

Iframily is a singleton and will allow you to initialize parent/child iframily instances.

Iframily.initParent(id, msgHandler, options) -> iframily instance

Iframily.initChild(id, msgHandler, options) -> iframily instance

Creates a parent/child iframily instance respectively (to be used in the parent/child frame) and returns it, if successful.

Param	Type	Description
id	string	A unique id to identify this iframily instance, this is used in order to match parent and child iframilies. Will abort and log an error if the id already exists in the current frame.
msgHandler	function	Optional - A handler for incoming messages from the paired iframily in the parent/child frame. The msgHandler can return back a response value or a promise that will be resolved/rejected with a response value.
options	object	Optional - Additional options, see possible options below:
options.onPairedHandler	function	Optional - A handler that will be invoked upon pairing.
options.onDisposedHandler	function	Optional - A handler that will be invoked when the instance is disposed.
options.targetOrigin	URI	Optional - The URI to use as the target origin for the postMessage call. Use this if you are passing sensitive data, see link for more info. Default is '*'.

Iframily.isIframilyMessage(event) -> boolean

If you manually listen to messages using the window "message" event you will also receive internal iframily messages. This method will return true for this events so you can easily identify them.

window.addEventListener("message", receiveMessage);

function receiveMessage(event) {
    // Ignore iframily messages.
    if (Iframily.isIframilyMessage(event)) {
        return;
    }

    // Handle other messages below:
    // ...
}

--- iframily instance ---

The iframily instance is the object returned when initing a new iframily using the initParent() or initChild() methods.

f.sendMessage(msg) -> Promise

Param	Type	Description
msg	serializable	The message to be sent, can be any serializable (see structured clone algorithm).

Returns a promise that will be resolved with the response value from the receiving iframily instance message handler. The promise will be rejected if the receiving iframily instance returned a rejected promise.

if the receiving iframily instance did not return an explicit response value in its message handler, the promise will be resolved with undefined.

f.dispose()

Dispose of the iframily instance, making it obsolete.

• You cannot reuse a disposed instance, you can however create a new instance with the same id.
• Any iframilies paired with this instance will still keep sending messages to the disposed instance but they will be ignored.

This method is useful when you have a parent frame which recreates the same child frame and you want to use the same id for the iframilies.

f.disposed -> boolean (read only)

Returns true if this iframily instance has been disposed.

f.id -> string (read only)

Returns the id that this iframily was inited with.

Usage example

// -------------------------
// In the parent frame.
// -------------------------
const Iframily = require('@ekolabs/iframily');

let msgHandler = function(msg) {
    console.log('parent got message:', msg);
};

let iframilyParent = Iframily.initParent('myUniqueId', msgHandler);

iframilyParent.sendMessage('do something')
    .then((response) => {
        console.log('parent got response:', response);
    });

iframilyParent.sendMessage('do something async')
    .then((response) => {
        console.log('parent got async response:', response);
    });

// -------------------------
// In the child frame.
// -------------------------
const Iframily = require('@ekolabs/iframily');

let msgHandler = function(msg) {
    console.log('child got message:', msg);

    if (msg === 'do something') {
        return 'OK! done!';
    } else if (msg === 'do something async') {
        return new Promise((resolve, reject) => {
            resolve('OK! done async!');
        });
    }
};

let iframilyChild = Iframily.initChild('myUniqueId', msgHandler);

iframilyChild.sendMessage({ text: 'fancy' });

• Your unique id (myUniqueId in the example) should match between parent and child.

Notes

• You can create multiple iframilies in each frame but the unique ids cannot be used more than once per frame (unless the previous one has been disposed).
• Parent can connect to one child only and vice versa (due to previous note).
• Designed for modern browsers (IE not supported).

Contributing

• npm run dev - builds unuglified bundle and watches for changes.
• npm run playground - launch a simple page with a parent and child frame iframilies to manually test out stuff.
• Please make all push requests against the develop branch.
• Please update/add tests coverage.
• Pay attention to linting (they will fail the production bundle build).
• npm run test - run tests.
  • npm run test-debug-mac or npm run test-debug-win for debugging the tests.
  • Tests run against the built bundle, so make sure your changes are built before running.
  • Tests require a modification in your hosts file (see note below).

Running tests require node >=10 and modifying your hosts file like so:

# iframily
127.0.0.1   sub1.domain1iframily.com
127.0.0.1   sub2.domain2iframily.com

When your done developing, make sure to run the production build via npm run build so the correct bundle will be committed to the dist folder.