@videsk/iframex

Javascript Iframe generator with dynamic content injection like HTML, Javascript, CSS, etc. and two way communication API.

Usage no npm install needed!

<script type="module">
  import videskIframex from 'https://cdn.skypack.dev/@videsk/iframex';
</script>

README

iFrameX

iFrameX is a javascript class for generate iframes with a really simple schema, also have a custom event listener.

This library is not compatible with IE11. Is designed only for modern browsers.

:rotating_light: CAUTION! Never send passwords or credentials via a custom event, can be intercepted by others scripts.

Index

Demo

Demo here

How to use

Use iFrameX is really easy, only need do two things:

const iframe = new iFrameX(options);
iframe.create();

Params

Params is an object can accept these parameters:

  • attributes: Object with attributes of iframe.
  • content: Object or Array with a content of iframe.
  • container: String or DOM element where append iframe in query format.
  • options: Object with some settings parameters.

attributes

const attributes = {
  width: 100,
  height: 100,
  class: 'myiframe'
};

content

This allows adding elements in Object schema. Can set these parameters in object:

  • type: String value of element to create. REQUIRED
  • append: String value of element where append the new element to create. By default is body. OPTIONAL
  • content: String value of content element, can be HTML, Javascript, CSS, etc. OPTIONAL
  • attr: Object value of attributes of element. OPTIONAL

Object example

const content = {
  type: script,
  append: 'body',
  content: `alert('This executed from iframe')`,
  attr: {
    async: true
  },
};

Array example

const content = [
  {
    type: 'link',
    append: 'head',
    attr: {
      href: 'https://cdn.example.com/assets/css/main.css' ,
      rel: 'stylesheet'
    },
  },
  {
    type: 'script',
    append: 'body',
    content: `alert('This executed from iframe')`,
    attr: {
      async: true
    },
  },
  {
    type: 'button',
    content: `My button`,
    attr: {
      class: 'mybutton',
      onclick: 'myFunction()'
    },
  },
];

container

Set where is appended the iframe, and the append value need be in elements query selector format. Read more about elements query selector format here.

By default, will be appended into body tag.

const append = '#myid';
const append = '[data-id="893283420949032"]';
const append = document.querySelector('#my-container');

options

In options parameter you can set:

  • ìd: String Custom if of iFrame
  • eventName: String Custom event name from iframe
  • gateway: Function Function to handle the custom event from iframe
const options = {
  id: 'my-custom-iframe-id',
  eventName: 'MyCustomEventName',
  gateway: function HandleEvent(data) {
    doSomething(data);
  },
};

Custom event listener and PostMessage

This provides the ability of listen custom events from iframe in a simple way.

To use it you need set eventName in options and gateway with a function can handle the event.

Listen event comes from iframe in parent

If you want provide states of HTML elements, data or anything you want from iframe to parent can use this feature, like this:

const options = {
    eventName: 'CustomEventName',
    gateway: function HandleEvent(data) {
        // Here data schema depend how you send from iframe
        doSomething(data);
    },
}; 

// Example content code in multiple lines
(() => {
    // This is how you can send from iframe to parent
    const event = new CustomEvent("CustomEventName", { detail: {date: new Date()} });
    window.parent.document.dispatchEvent(event);
})();

const content = {
    type: 'script',
    content: '(() => window.parent.document.dispatchEvent(new CustomEvent("CustomEventName", { detail: {date: new Date()} })))()', // Example content in one line
}; 

const iframe = new IframeX({content, options});
iframe.create();

The above example code, create an iframe and when this will render, sent custom event CustomEventName with data, that contains an Object with date: new Date(). (Obviously data is completely customizable)

Listen event in iframe from parent

To listen events in iframe that comes from outside is really simple:

In iframe

function newMessage(event) {
    const data = event.detail;
    doSomething(data);
}

window.addEventListener('CustomEventName', newMessage);

In parent

iframe.sendMessage('CustomEventName', {date: new Date()});

Is too important the event listener on iframe will set before send the event from the parent. Is highly recommended set event listener on iframe before all scripts on the body!

Why not use PostMessage?

Because you need set message listener before iframe will render on a parent. And can't create multiples custom events before and after iframe was rendered.

That means pass all data via PostMessage making too complex handle different events and data.

If you're curious is possible handle multiple events with PostMessage with the following schema:

window.addEventListener('message', newMessage);

function newMessage(event) {
    const {event, data} = event.data;
    eventHandler(event, data); // In this function need use if or key object access by event name.   
}

You can use PostMessage in parallel with iFrameX!

Some known bugs

If have error with injection of content, try change order in object content of scripts that block the DOM draw, and move to the final. For example alert('hi') block DOM drawing, try move to the final and works!.

Issue #1.

License

LGPL-2.1 License - By Videsk™