CommLink

CommLink is an open source library for userscripts that enables cross-window communication via the userscript storage. It provides a simple and efficient way to send and receive messages between different instances of a userscript running in separate browser windows.

Installation

To use CommLink in your userscript, you need to add the following lines to the userscript header,

// @grant GM_getValue// @grant GM_setValue// @grant GM_deleteValue// @grant GM_listValues// @require https://greasyfork.org/scripts/470418-commlink-js/code/CommLinkjs.js?version=1217207

Warning DO NOT REQUIRE ANY FILES FROM THIS REPOSITORY DIRECTLY! CommLink is currently not in its final form and the logic might change in the future. Only use the version controlled GreasyFork URL to require CommLink for now. Thank you so much for your understanding.

Usage

I'm so sorry, but I am too lazy to write documentation right now. You can check the examples to get an idea.

CommLink is currently just a byproduct of the A.C.A.S project. I wouldn't use CommLink for your personal large-scale projects.

Examples

Site #1

constCommLink=newCommLinkHandler(`frontend_${commLinkInstanceID}`,{'singlePacketResponseWaitTime': 1500,'maxSendAttempts': 3,'statusCheckInterval': 1,'silentMode': false});// manually register a command so that the variables are dynamicCommLink.commands['createInstance']=async()=>{returnawaitCommLink.send('mum','createInstance',{'domain': window.location.hostname.replace('www.',''),'instanceID': commLinkInstanceID,'chessVariant': getSiteChessVariant(),'playerColor': getPlayerColorVariable()});}CommLink.registerSendCommand('ping',{commlinkID: 'mum',data: 'ping'});CommLink.registerSendCommand('pingInstance',{data: 'ping'});CommLink.registerSendCommand('log');CommLink.registerSendCommand('updateBoardOrientation');CommLink.registerSendCommand('updateBoardFen');CommLink.registerSendCommand('calculateBestMoves');CommLink.registerListener(`backend_${commLinkInstanceID}`,packet=>{try{switch(packet.command){case'ping':
return`pong (took ${Date.now()-packet.date}ms)`;case'getFen':
returnnewFenUtils().getFen();case'removeSiteMoveMarkings':
removeSiteMoveMarkings();returntrue;case'markMoveToSite':
markMoveToSite(packet.data);returntrue;}}catch(e){returnnull;}});// [other code] //CommLink.commands.log(`Hello World!`);

Site #2 file #1

constMainCommLink=newUSERSCRIPT.CommLinkHandler('mum',{'singlePacketResponseWaitTime': 1500,'maxSendAttempts': 3,'statusCheckInterval': 1});MainCommLink.registerListener('mum',packet=>{try{switch(packet.command){case'ping':
return`pong (took ${Date.now()-packet.date}ms)`;case'createInstance':
log.info('Received request to create another engine instance!');constdata=packet.data;console.log(data);createInstance(data.domain,data.instanceID,data.chessVariant,data.playerColor);returntrue;}}catch(e){console.error(e);returnnull;}});

Site #2 file #2

this.CommLink=newUSERSCRIPT.CommLinkHandler(`backend_${this.instanceID}`,{'singlePacketResponseWaitTime': 1500,'maxSendAttempts': 3,'statusCheckInterval': 1});this.CommLink.registerSendCommand('ping');this.CommLink.registerSendCommand('getFen');this.CommLink.registerSendCommand('removeSiteMoveMarking');this.CommLink.registerSendCommand('markMoveToSite');this.CommLinkReceiver=this.CommLink.registerListener(`frontend_${this.instanceID}`,packet=>{try{if(this.instanceReady)returnthis.processPacket(packet);this.unprocessedPackets.push(packet);returntrue;}catch(e){console.error('Instance:',this.domain,this.instanceID,e);returnnull;}});

Compatibility

CommLink relies on userscript grants such as GM_getValue, GM_setValue, GM_deleteValue, and GM_listValues to access the userscript storage. Please ensure that your userscript has the necessary grants for CommLink to function correctly.

If any of the required grants are missing, CommLink will display an alert message