cbp-lib/src/session/SessionIFrame.js

Libraries for cbp

'use strict'

import {Log} from '../_helpers/Log'

let _ = typeof window !== 'undefined' ? window : typeof global !== 'undefined' ? global : {};
let $ = _.document

export class SessionIFrame {
    constructor(callback, metadata, interval = 1000*120) {
        this._callback = callback
        this._interval = interval
        this._metadata = metadata
        this._iframe_origin = metadata.authorization_server
        this._iframe = $.createElement('iframe')
        this._iframe.style.visibility = 'hidden'
        this._iframe.style.display = 'none'
        this._iframe.style.height = '0'
        this._iframe.style.width = '0'
        this._iframe.src = this._metadata.check_session_iframe
    }

    load() {
        return new Promise((resolve) => {
            this._iframe.onload = () => {
                resolve()
            }

            $.body.appendChild(this._iframe)
            this._recieveMessage = this._message.bind(this)
            _.addEventListener("message", this._recieveMessage, false)
        })
    }

    start(session_state) {
        if (this._session_state !== session_state) {
            Log.debug("SessionIFrame.start" )

            this.stop()

            this._session_state = session_state

            let check = () => {
                Log.debug("SessionIFrame.check : Checking session state..." )
                let text = this._metadata.client_id + " " + this._session_state
                this._iframe.contentWindow.postMessage(text, this._iframe_origin)
            }
    
            check()
            // set up timer call
            this._timer = _.setInterval(check, this._interval)
        }
    }

    _message(e) {
        Log.debug("SessionIFrame._message: called message function...." )
        if (e.origin === this._iframe_origin &&
            e.source === this._iframe.contentWindow) {

                if (e.data === 'error') {
                    Log.error("SessionIFrame: Error " + e.data)
                    this.stop()
                }
                else if(e.data === 'changed') {
                    // call the callback function
                    Log.debug("SessionIFrame : session changed from op..." )
                    this.stop()
                    this._callback(e.data)
                }
                else {
                    Log.debug("SessionIFrame: " + e.data)
                }
        }
    }

    stop() {
        this._session_state = null
        if (this._timer) {
            Log.debug("SessionIFrame: stopping check state...")
            _.clearInterval(this._timer)
            this._timer = null
        }
    }
}