yggdrasil-trackers/js/ZeroFrame.js

/*
Original code is Copyright (c) 2020 ZeroNet project.
Original code was released under the GPLv2 license by ZeroNet project, December 2016.
Original code was rereleased under the MIT license by ZeroNet project, March 2020.

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

// Version 1.0.0 - Initial release
// Version 1.1.0 (2017-08-02) - Added cmdp function that returns promise instead of using callback
// Version 1.2.0 (2017-08-02) - Added Ajax monkey patch to emulate XMLHttpRequest over ZeroFrame API
// Version 1.3.0 (2018-12-05) - Added monkey patch for fetch API
// Version 1.3.1 (2019-09-02) - Fix memory leak while handling responses
// Version 1.4.0 (2019-12-11) - Awaitable monkeyPatchAjax function

const CMD_INNER_READY = 'innerReady'
const CMD_RESPONSE = 'response'
const CMD_WRAPPER_READY = 'wrapperReady'
const CMD_PING = 'ping'
const CMD_PONG = 'pong'
const CMD_WRAPPER_OPENED_WEBSOCKET = 'wrapperOpenedWebsocket'
const CMD_WRAPPER_CLOSE_WEBSOCKET = 'wrapperClosedWebsocket'

class ZeroFrame {
    constructor(url) {
        this.url = url
        this.waiting_cb = {}
        this.wrapper_nonce = document.location.href.replace(/.*wrapper_nonce=([A-Za-z0-9]+).*/, "$1")
        this.connect()
        this.next_message_id = 1
        this.init()
    }

    init() {
        return this
    }

    connect() {
        this.target = window.parent
        window.addEventListener('message', e => this.onMessage(e), false)
        this.cmd(CMD_INNER_READY)
    }

    onMessage(e) {
        let message = e.data
        let cmd = message.cmd
        if (cmd === CMD_RESPONSE) {
            if (this.waiting_cb[message.to] !== undefined) {
                this.waiting_cb[message.to](message.result)
                delete this.waiting_cb[message.to]
            }
            else {
                this.log("Websocket callback not found:", message)
            }
        } else if (cmd === CMD_WRAPPER_READY) {
            this.cmd(CMD_INNER_READY)
        } else if (cmd === CMD_PING) {
            this.response(message.id, CMD_PONG)
        } else if (cmd === CMD_WRAPPER_OPENED_WEBSOCKET) {
            this.onOpenWebsocket()
        } else if (cmd === CMD_WRAPPER_CLOSE_WEBSOCKET) {
            this.onCloseWebsocket()
        } else {
            this.onRequest(cmd, message)
        }
    }

    onRequest(cmd, message) {
        this.log("Unknown request", message)
    }

    response(to, result) {
        this.send({
            cmd: CMD_RESPONSE,
            to: to,
            result: result
        })
    }

    cmd(cmd, params={}, cb=null) {
        this.send({
            cmd: cmd,
            params: params
        }, cb)
    }

    cmdp(cmd, params={}) {
        return new Promise((resolve, reject) => {
            this.cmd(cmd, params, (res) => {
                if (res && res.error) {
                    reject(res.error)
                } else {
                    resolve(res)
                }
            })
        })
    }

    send(message, cb=null) {
        message.wrapper_nonce = this.wrapper_nonce
        message.id = this.next_message_id
        this.next_message_id++
        this.target.postMessage(message, '*')
        if (cb) {
            this.waiting_cb[message.id] = cb
        }
    }

    log(...args) {
        console.log.apply(console, ['[ZeroFrame]'].concat(args))
    }

    onOpenWebsocket() {
        this.log('Websocket open')
    }

    onCloseWebsocket() {
        this.log('Websocket close')
    }

    async monkeyPatchAjax() {
        var page = this
        XMLHttpRequest.prototype.realOpen = XMLHttpRequest.prototype.open
        var newOpen = function (method, url, async) {
            url += "?ajax_key=" + page.ajax_key
            return this.realOpen(method, url, async)
        }
        XMLHttpRequest.prototype.open = newOpen

        window.realFetch = window.fetch
        var newFetch = function (url) {
            url += "?ajax_key=" + page.ajax_key
            return window.realFetch(url)
        }
        window.fetch = newFetch

        this.ajax_key = await page.cmdp("wrapperGetAjaxKey", [])
    }
}