Revert "Add server sent events (#5279)" (#5880)

This reverts commit 17b4f53ba2 according to Github Desktop.

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core/language/en-GB/Help/listen.tid

@@ -22,7 +22,6 @@ All parameters are optional with safe defaults, and can be specified in any orde
 * ''readers'' - comma-separated list of principals allowed to read from this wiki
 * ''writers'' - comma-separated list of principals allowed to write to this wiki
 * ''csrf-disable'' - set to "yes" to disable CSRF checks (defaults to "no")
-* ''sse-enabled'' - set to "yes" to enable Server-sent events (defaults to "no")
 * ''root-tiddler'' - the tiddler to serve at the root (defaults to "$:/core/save/all")
 * ''root-render-type'' - the content type to which the root tiddler should be rendered (defaults to "text/plain")
 * ''root-serve-type'' - the content type with which the root tiddler should be served (defaults to "text/html")

core/modules/server/routes/get-status.js

@@ -21,7 +21,6 @@ exports.handler = function(request,response,state) {
 		username: state.authenticatedUsername || state.server.get("anon-username") || "",
 		anonymous: !state.authenticatedUsername,
 		read_only: !state.server.isAuthorized("writers",state.authenticatedUsername),
-		sse_enabled: state.server.get("sse-enabled") === "yes",
 		space: {
 			recipe: "default"
 		},

core/modules/server/server-sent-events.js

@@ -1,70 +0,0 @@
-/*\
-title: $:/core/modules/server/server-sent-events.js
-type: application/javascript
-module-type: library
-\*/
-(function(){
-
-/*jslint node: true, browser: true */
-/*global $tw: false */
-"use strict";
-
-/*
-parameters:
-		prefix - usually the plugin path, such as `plugins/tiddlywiki/tiddlyweb`. The
-			route will match `/events/${prefix}` exactly.
-
-		handler - a function that will be called each time a request comes in with the
-			request and state from the route and an emit function to call.
-*/
-
-var ServerSentEvents = function ServerSentEvents(prefix, handler) {
-	this.handler = handler;
-	this.prefix = prefix;
-};
-
-ServerSentEvents.prototype.getExports = function() {
-	return {
-		bodyFormat: "stream",
-		method: "GET",
-		path: new RegExp("^/events/" + this.prefix + "$"),
-		handler: this.handleEventRequest.bind(this)
-	};
-};
-
-ServerSentEvents.prototype.handleEventRequest = function(request,response,state) {
-	if(ServerSentEvents.prototype.isEventStreamRequest(request)) {
-		response.writeHead(200, {
-			"Content-Type": "text/event-stream",
-			"Cache-Control": "no-cache",
-			"Connection": "keep-alive"
-		});
-		this.handler(request,state,this.emit.bind(this,response),this.end.bind(this,response));
-	} else {
-		response.writeHead(406,"Not Acceptable",{});
-		response.end();
-	}
-};
-
-ServerSentEvents.prototype.isEventStreamRequest = function(request) {
-	return request.headers.accept &&
-		request.headers.accept.match(/^text\/event-stream/);
-};
-
-ServerSentEvents.prototype.emit = function(response,event,data) {
-	if(typeof event !== "string" || event.indexOf("\n") !== -1) {
-		throw new Error("Type must be a single-line string");
-	}
-	if(typeof data !== "string" || data.indexOf("\n") !== -1) {
-		throw new Error("Data must be a single-line string");
-	}
-	response.write("event: " + event + "\ndata: " + data + "\n\n", "utf8");
-};
-
-ServerSentEvents.prototype.end = function(response) {
-	response.end();
-};
-
-exports.ServerSentEvents = ServerSentEvents;
-
-})();

core/modules/syncer.js

@@ -20,7 +20,6 @@ Syncer.prototype.titleIsAnonymous = "$:/status/IsAnonymous";
 Syncer.prototype.titleIsReadOnly = "$:/status/IsReadOnly";
 Syncer.prototype.titleUserName = "$:/status/UserName";
 Syncer.prototype.titleSyncFilter = "$:/config/SyncFilter";
-Syncer.prototype.titleSyncDisablePolling = "$:/config/SyncDisablePolling";
 Syncer.prototype.titleSyncPollingInterval = "$:/config/SyncPollingInterval";
 Syncer.prototype.titleSyncDisableLazyLoading = "$:/config/SyncDisableLazyLoading";
 Syncer.prototype.titleSavedNotification = "$:/language/Notifications/Save/Done";
@@ -268,7 +267,7 @@ Syncer.prototype.getStatus = function(callback) {
 		// Mark us as not logged in
 		this.wiki.addTiddler({title: this.titleIsLoggedIn,text: "no"});
 		// Get login status
-		this.syncadaptor.getStatus(function(err,isLoggedIn,username,isReadOnly,isAnonymous,isPollingDisabled) {
+		this.syncadaptor.getStatus(function(err,isLoggedIn,username,isReadOnly,isAnonymous) {
 			if(err) {
 				self.logger.alert(err);
 			} else {
@@ -279,9 +278,6 @@ Syncer.prototype.getStatus = function(callback) {
 				if(isLoggedIn) {
 					self.wiki.addTiddler({title: self.titleUserName,text: username || ""});
 				}
-				if(isPollingDisabled) {
-					self.wiki.addTiddler({title: self.titleSyncDisablePolling, text: "yes"});
-				}
 			}
 			// Invoke the callback
 			if(callback) {
@@ -305,15 +301,12 @@ Syncer.prototype.syncFromServer = function() {
 			}
 		},
 		triggerNextSync = function() {
-			if(pollingEnabled) {
 			self.pollTimerId = setTimeout(function() {
 				self.pollTimerId = null;
 				self.syncFromServer.call(self);
 			},self.pollTimerInterval);
-			}
 		},
-		syncSystemFromServer = (self.wiki.getTiddlerText("$:/config/SyncSystemTiddlersFromServer") === "yes"),
+		syncSystemFromServer = (self.wiki.getTiddlerText("$:/config/SyncSystemTiddlersFromServer") === "yes" ? true : false);
-		pollingEnabled = (self.wiki.getTiddlerText(self.titleSyncDisablePolling) !== "yes");
 	if(this.syncadaptor && this.syncadaptor.getUpdatedTiddlers) {
 		this.logger.log("Retrieving updated tiddler list");
 		cancelNextSync();

editions/tw5.com/tiddlers/webserver/WebServer Parameter_ sse-enabled.tid

@@ -1,11 +0,0 @@
-caption: sse-enabled
-created: 20210113204602693
-modified: 20210115120126953
-tags: [[WebServer Parameters]]
-title: WebServer Parameter: sse-enabled
-type: text/vnd.tiddlywiki
-
-The [[web server configuration parameter|WebServer Parameters]] ''sse-enabled'' enables [[Server sent events|https://en.wikipedia.org/wiki/Server-sent_events]], allowing changes to be propagated in almost real time to all browser windows or tabs.
-
-Setting ''sse-enabled'' to `yes` enables Server-sent events; `no`, or any other value, disables them.
-

plugins/tiddlywiki/tiddlyweb/sse-client.js

@@ -1,56 +0,0 @@
-/*\
-title: $:/plugins/tiddlywiki/tiddlyweb/sse-client.js
-type: application/javascript
-module-type: startup
-
-GET /recipes/default/tiddlers/:title
-
-\*/
-(function(){
-
-/*jslint node: true, browser: true */
-/*global $tw: false */
-"use strict";
-
-exports.name = "/events/plugins/tiddlywiki/tiddlyweb";
-exports.after = ["startup"];
-exports.synchronous = true;
-exports.platforms = ["browser"];
-exports.startup = function() {
-	// Make sure we're actually being used
-	if($tw.syncadaptor.name !== "tiddlyweb") {
-		return;
-	}
-	// Get the mount point in case a path prefix is used
-	var host = $tw.syncadaptor.getHost();
-	// Make sure it ends with a slash (it usually does)
-	if(host[host.length - 1] !== "/") {
-		host += "/";
-	}
-	// Setup the event listener
-	setupEvents(host);
-};
-
-function debounce(callback) {
-	var timeout = null;
-	return function() {
-		clearTimeout(timeout);
-		timeout = setTimeout(callback,$tw.syncer.throttleInterval);
-	};
-}
-
-function setupEvents(host) {
-	if(window.EventSource) {
-		var events = new EventSource(host + "events/plugins/tiddlywiki/tiddlyweb");
-		var debouncedSync = debounce($tw.syncer.syncFromServer.bind($tw.syncer));
-		events.addEventListener("change",debouncedSync);
-		events.onerror = function() {
-			events.close();
-			setTimeout(function() {
-				setupEvents(host);
-			},$tw.syncer.errorRetryInterval);
-		};
-	}
-}
-
-})();

plugins/tiddlywiki/tiddlyweb/sse-server.js

@@ -1,94 +0,0 @@
-/*\
-title: $:/plugins/tiddlywiki/tiddlyweb/sse-server.js
-type: application/javascript
-module-type: route
-
-GET /events/plugins/tiddlywiki/tiddlyweb
-
-\*/
-(function(){
-
-/*jslint node: true, browser: true */
-/*global $tw: false */
-"use strict";
-
-var wikis = [];
-var connections = [];
-
-/*
-Setup up the array for this wiki and add the change listener
-*/
-function setupWiki(wiki) {
-	var index = wikis.length;
-	// Add a new array for this wiki (object references work as keys)
-	wikis.push(wiki);
-	connections.push([]);
-	// Listen to change events for this wiki
-	wiki.addEventListener("change",function(changes) {
-		var jsonChanges = JSON.stringify(changes);
-		getWikiConnections(wiki).forEach(function(item) {
-			item.emit("change",jsonChanges);
-		});
-	});
-	return index;
-}
-
-/*
-Setup this particular wiki if we haven't seen it before
-*/
-function ensureWikiSetup(wiki) {
-	if(wikis.indexOf(wiki) === -1) {
-		setupWiki(wiki);
-	}
-}
-
-/*
-Return the array of connections for a particular wiki
-*/
-function getWikiConnections(wiki) {
-	return connections[wikis.indexOf(wiki)];
-}
-
-function addWikiConnection(wiki,connection) {
-	getWikiConnections(wiki).push(connection);
-}
-
-function removeWikiConnection(wiki,connection) {
-	var wikiConnections = getWikiConnections(wiki);
-	var index = wikiConnections.indexOf(connection);
-	if(index !== -1) {
-		wikiConnections.splice(index,1);
-	}
-}
-
-function handleConnection(request,state,emit,end) {
-	if(isDisabled(state)) {
-		return;
-	}
-
-	ensureWikiSetup(state.wiki);
-	// Add the connection to the list of connections for this wiki
-	var connection = {
-		request: request,
-		state: state,
-		emit: emit,
-		end: end
-	};
-	addWikiConnection(state.wiki,connection);
-	request.on("close",function() {
-		removeWikiConnection(state.wiki,connection);
-	});
-}
-
-function isDisabled(state) {
-	return state.server.get("sse-enabled") !== "yes";
-}
-
-// Import the ServerSentEvents class
-var ServerSentEvents = require("$:/core/modules/server/server-sent-events.js").ServerSentEvents;
-// Instantiate the class
-var events = new ServerSentEvents("plugins/tiddlywiki/tiddlyweb", handleConnection);
-// Export the route definition for this server sent events instance
-module.exports = events.getExports();
-
-})();

plugins/tiddlywiki/tiddlyweb/tiddlywebadaptor.js

@@ -91,12 +91,10 @@ TiddlyWebAdaptor.prototype.getStatus = function(callback) {
 				self.isLoggedIn = json.username !== "GUEST";
 				self.isReadOnly = !!json["read_only"];
 				self.isAnonymous = !!json.anonymous;
-
-				var isSseEnabled = !!json.sse_enabled;
 			}
 			// Invoke the callback if present
 			if(callback) {
-				callback(null,self.isLoggedIn,json.username,self.isReadOnly,self.isAnonymous,isSseEnabled);
+				callback(null,self.isLoggedIn,json.username,self.isReadOnly,self.isAnonymous);
 			}
 		}
 	});