Improvements in WebSocket extension

* Implement proper `hx-trigger` support
* Expose trigger handling API to extensions
* Implement safe message sending with sending queue
* Fix `ws-send` attributes connecting in new elements
* Fix OOB swapping of multiple elements in response

src/ext/ws.js

@@ -58,6 +58,9 @@ This extension adds support for WebSockets to htmx.  See /www/extensions/ws.md f
 				forEach(queryAttributeOnThisOrChildren(parent, "ws-connect"), function(child) {
 					ensureWebSocket(child)
 				});
+				forEach(queryAttributeOnThisOrChildren(parent, "ws-send"), function (child) {
+					ensureWebSocketSend(child)
+				});
 			}
 		}
 	});
@@ -125,8 +128,11 @@ This extension adds support for WebSockets to htmx.  See /www/extensions/ws.md f
 		/** @type {WebSocket} */
 		var socket = htmx.createWebSocket(wssSource);
 
+		var messageQueue = [];
+
 		socket.onopen = function (e) {
 			retryCount = 0;
+			handleQueuedMessages(messageQueue, socket);
 		}
 
 		socket.onclose = function (e) {
@@ -158,25 +164,42 @@ This extension adds support for WebSockets to htmx.  See /www/extensions/ws.md f
 			var fragment = api.makeFragment(response);
 
 			if (fragment.children.length) {
-				for (var i = 0; i < fragment.children.length; i++) {
+				var children = Array.from(fragment.children);
-					api.oobSwap(api.getAttributeValue(fragment.children[i], "hx-swap-oob") || "true", fragment.children[i], settleInfo);
+				for (var i = 0; i < children.length; i++) {
+					api.oobSwap(api.getAttributeValue(children[i], "hx-swap-oob") || "true", children[i], settleInfo);
 				}
 			}
 
 			api.settleImmediately(settleInfo.tasks);
 		});
 
-		// Re-connect any ws-send commands as well.
+		// Put the WebSocket into the HTML Element's custom data.
-		forEach(queryAttributeOnThisOrChildren(elt, "ws-send"), function(child) {
+		api.getInternalData(elt).webSocket = socket;
-			var legacyAttribute = api.getAttributeValue(child, "hx-ws");
+		api.getInternalData(elt).webSocketMessageQueue = messageQueue;
+	}
+
+	/**
+	 * ensureWebSocketSend attaches trigger handles to elements with
+	 * "ws-send" attribute
+	 * @param {HTMLElement} elt
+	 */
+	function ensureWebSocketSend(elt) {
+		var legacyAttribute = api.getAttributeValue(elt, "hx-ws");
 		if (legacyAttribute && legacyAttribute !== 'send') {
 			return;
 		}
-			processWebSocketSend(elt, child);
-		});
 
-		// Put the WebSocket into the HTML Element's custom data.
+		var webSocketParent = api.getClosestMatch(elt, hasWebSocket)
-		api.getInternalData(elt).webSocket = socket;
+		processWebSocketSend(webSocketParent, elt);
+	}
+
+	/**
+	 * hasWebSocket function checks if a node has webSocket instance attached
+	 * @param {HTMLElement} node
+	 * @returns {boolean}
+	 */
+	function hasWebSocket(node) {
+		return api.getInternalData(node).webSocket != null;
 	}
 
 	/**
@@ -186,8 +209,12 @@ This extension adds support for WebSockets to htmx.  See /www/extensions/ws.md f
 	 * @param {HTMLElement} child
 	 */
 	function processWebSocketSend(parent, child) {
-		child.addEventListener(api.getTriggerSpecs(child)[0].trigger, function (evt) {
+		var nodeData = api.getInternalData(child);
+		let triggerSpecs = api.getTriggerSpecs(child);
+		triggerSpecs.forEach(function(ts) {
+			api.addTriggerHandler(child, ts, nodeData, function (evt) {
 				var webSocket = api.getInternalData(parent).webSocket;
+				var messageQueue = api.getInternalData(parent).webSocketMessageQueue;
 				var headers = api.getHeaders(child, parent);
 				var results = api.getInputValues(child, 'post');
 				var errors = results.errors;
@@ -200,11 +227,43 @@ This extension adds support for WebSockets to htmx.  See /www/extensions/ws.md f
 					api.triggerEvent(child, 'htmx:validation:halted', errors);
 					return;
 				}
-			webSocket.send(JSON.stringify(filteredParameters));
+				webSocketSend(webSocket, JSON.stringify(filteredParameters), messageQueue);
 				if(api.shouldCancel(evt, child)){
 					evt.preventDefault();
 				}
 			});
+		});
+	}
+
+	/**
+	 * webSocketSend provides a safe way to send messages through a WebSocket.
+	 * It checks that the socket is in OPEN state and, otherwise, awaits for it.
+	 * @param {WebSocket} socket
+	 * @param {string} message
+	 * @param {string[]} messageQueue
+	 * @return {boolean}
+	 */
+	function webSocketSend(socket, message, messageQueue) {
+		if (socket.readyState != socket.OPEN) {
+			messageQueue.push(message);
+		} else {
+			socket.send(message);
+		}
+	}
+
+	/**
+	 * handleQueuedMessages sends messages awaiting in the message queue
+	 */
+	function handleQueuedMessages(messageQueue, socket) {
+		while (messageQueue.length > 0) {
+			var message = messageQueue[0]
+			if (socket.readyState == socket.OPEN) {
+				socket.send(message);
+				messageQueue.shift()
+			} else {
+				break;
+			}
+		}
 	}
 
 	/**
@@ -293,3 +352,4 @@ This extension adds support for WebSockets to htmx.  See /www/extensions/ws.md f
 	}
 
 })();
+

src/htmx.js

@@ -76,6 +76,7 @@ return (function () {
 
         /** @type {import("./htmx").HtmxInternalApi} */
         var internalAPI = {
+            addTriggerHandler: addTriggerHandler,
             bodyContains: bodyContains,
             canAccessLocalStorage: canAccessLocalStorage,
             filterValues: filterValues,
@@ -172,13 +173,11 @@ return (function () {
          * @returns {HTMLElement | null}
          */
         function getClosestMatch(elt, condition) {
-            if (condition(elt)) {
+            while (elt && !condition(elt)) {
-                return elt;
+                elt = parentElt(elt);
-            } else if (parentElt(elt)) {
-                return getClosestMatch(parentElt(elt), condition);
-            } else {
-                return null;
             }
+
+            return elt ? elt : null;
         }
 
         function getAttributeValueWithDisinheritance(initialElement, ancestor, attributeName){
@@ -1188,14 +1187,14 @@ return (function () {
             getInternalData(elt).cancelled = true;
         }
 
-        function processPolling(elt, verb, path, spec) {
+        function processPolling(elt, handler, spec) {
             var nodeData = getInternalData(elt);
             nodeData.timeout = setTimeout(function () {
                 if (bodyContains(elt) && nodeData.cancelled !== true) {
                     if (!maybeFilterEvent(spec, makeEvent('hx:poll:trigger', {triggerSpec:spec, target:elt}))) {
-                        issueAjaxRequest(verb, path, elt);
+                        handler(elt);
                     }
-                    processPolling(elt, verb, getAttributeValue(elt, "hx-" + verb), spec);
+                    processPolling(elt, handler, spec);
                 }
             }, spec.pollInterval);
         }
@@ -1223,7 +1222,9 @@ return (function () {
                     path = getRawAttribute(elt, 'action');
                 }
                 triggerSpecs.forEach(function(triggerSpec) {
-                    addEventListener(elt, verb, path, nodeData, triggerSpec, true);
+                    addEventListener(elt, function(evt) {
+                        issueAjaxRequest(verb, path, elt, evt)
+                    }, nodeData, triggerSpec, true);
                 });
             }
         }
@@ -1267,7 +1268,7 @@ return (function () {
             return false;
         }
 
-        function addEventListener(elt, verb, path, nodeData, triggerSpec, explicitCancel) {
+        function addEventListener(elt, handler, nodeData, triggerSpec, explicitCancel) {
             var eltsToListenOn;
             if (triggerSpec.from) {
                 eltsToListenOn = querySelectorAllExt(elt, triggerSpec.from);
@@ -1328,17 +1329,15 @@ return (function () {
 
                         if (triggerSpec.throttle) {
                             if (!elementData.throttle) {
-                                issueAjaxRequest(verb, path, elt, evt);
+                                handler(elt, evt);
                                 elementData.throttle = setTimeout(function () {
                                     elementData.throttle = null;
                                 }, triggerSpec.throttle);
                             }
                         } else if (triggerSpec.delay) {
-                            elementData.delayed = setTimeout(function () {
+                            elementData.delayed = setTimeout(function() { handler(elt, evt) }, triggerSpec.delay);
-                                issueAjaxRequest(verb, path, elt, evt);
-                            }, triggerSpec.delay);
                         } else {
-                            issueAjaxRequest(verb, path, elt, evt);
+                            handler(elt, evt);
                         }
                     }
                 };
@@ -1356,7 +1355,7 @@ return (function () {
 
         var windowIsScrolling = false // used by initScrollHandler
         var scrollHandler = null;
-        function initScrollHandler() {
+        function initScrollHandler(handler) {
             if (!scrollHandler) {
                 scrollHandler = function() {
                     windowIsScrolling = true
@@ -1366,25 +1365,22 @@ return (function () {
                     if (windowIsScrolling) {
                         windowIsScrolling = false;
                         forEach(getDocument().querySelectorAll("[hx-trigger='revealed'],[data-hx-trigger='revealed']"), function (elt) {
-                            maybeReveal(elt);
+                            maybeReveal(elt, handler);
                         })
                     }
                 }, 200);
             }
         }
 
-        function maybeReveal(elt) {
+        function maybeReveal(elt, handler) {
             if (!hasAttribute(elt,'data-hx-revealed') && isScrolledIntoView(elt)) {
                 elt.setAttribute('data-hx-revealed', 'true');
                 var nodeData = getInternalData(elt);
                 if (nodeData.initialized) {
-                    issueAjaxRequest(nodeData.verb, nodeData.path, elt);
+                    handler(elt);
                 } else {
                     // if the node isn't initialized, wait for it before triggering the request
-                    elt.addEventListener("htmx:afterProcessNode",
+                    elt.addEventListener("htmx:afterProcessNode", function(evt) { handler(elt) }, {once: true});
-                        function () {
-                            issueAjaxRequest(nodeData.verb, nodeData.path, elt);
-                        }, {once: true});
                 }
             }
         }
@@ -1571,14 +1567,14 @@ return (function () {
             }
         }
 
-        function processSSETrigger(elt, verb, path, sseEventName) {
+        function processSSETrigger(elt, handler, sseEventName) {
             var sseSourceElt = getClosestMatch(elt, hasEventSource);
             if (sseSourceElt) {
                 var sseEventSource = getInternalData(sseSourceElt).sseEventSource;
                 var sseListener = function () {
                     if (!maybeCloseSSESource(sseSourceElt)) {
                         if (bodyContains(elt)) {
-                            issueAjaxRequest(verb, path, elt);
+                            handler(elt);
                         } else {
                             sseEventSource.removeEventListener(sseEventName, sseListener);
                         }
@@ -1604,11 +1600,11 @@ return (function () {
 
         //====================================================================
 
-        function loadImmediately(elt, verb, path, nodeData, delay) {
+        function loadImmediately(elt, handler, nodeData, delay) {
             var load = function(){
                 if (!nodeData.loaded) {
                     nodeData.loaded = true;
-                    issueAjaxRequest(verb, path, elt);
+                    handler(elt);
                 }
             }
             if (delay) {
@@ -1627,11 +1623,21 @@ return (function () {
                     nodeData.path = path;
                     nodeData.verb = verb;
                     triggerSpecs.forEach(function(triggerSpec) {
+                        addTriggerHandler(elt, triggerSpec, nodeData, function (elt, evt) {
+                            issueAjaxRequest(verb, path, elt, evt)
+                        })
+                    });
+                }
+            });
+            return explicitAction;
+        }
+
+        function addTriggerHandler(elt, triggerSpec, nodeData, handler) {
             if (triggerSpec.sseEvent) {
-                            processSSETrigger(elt, verb, path, triggerSpec.sseEvent);
+                processSSETrigger(elt, handler, triggerSpec.sseEvent);
             } else if (triggerSpec.trigger === "revealed") {
-                            initScrollHandler();
+                initScrollHandler(handler);
-                            maybeReveal(elt);
+                maybeReveal(elt, handler);
             } else if (triggerSpec.trigger === "intersect") {
                 var observerOptions = {};
                 if (triggerSpec.root) {
@@ -1650,21 +1656,17 @@ return (function () {
                     }
                 }, observerOptions);
                 observer.observe(elt);
-                            addEventListener(elt, verb, path, nodeData, triggerSpec);
+                addEventListener(elt, handler, nodeData, triggerSpec);
             } else if (triggerSpec.trigger === "load") {
                 if (!maybeFilterEvent(triggerSpec, makeEvent("load", {elt:elt}))) {
-                                loadImmediately(elt, verb, path, nodeData, triggerSpec.delay);
+                                loadImmediately(elt, handler, nodeData, triggerSpec.delay);
                             }
             } else if (triggerSpec.pollInterval) {
                 nodeData.polling = true;
-                            processPolling(elt, verb, path, triggerSpec);
+                processPolling(elt, handler, triggerSpec);
             } else {
-                            addEventListener(elt, verb, path, nodeData, triggerSpec);
+                addEventListener(elt, handler, nodeData, triggerSpec);
             }
-                    });
-                }
-            });
-            return explicitAction;
         }
 
         function evalScript(script) {
@@ -3177,3 +3179,4 @@ return (function () {
     }
 )()
 }));
+