Vendor libraries

static/style.css

@@ -168,3 +168,24 @@ ul.dir li .material-symbols-outlined {
   font-weight: bold;
   text-align: center;
 }
+
+@font-face {
+  font-family: 'Material Symbols Outlined';
+  font-style: normal;
+  font-weight: 400;
+  src: url(/static/vendor/material-symbols-outlined.woff2) format('truetype');
+}
+
+.material-symbols-outlined {
+  font-family: 'Material Symbols Outlined';
+  font-weight: normal;
+  font-style: normal;
+  font-size: 24px;
+  line-height: 1;
+  letter-spacing: normal;
+  text-transform: none;
+  display: inline-block;
+  white-space: nowrap;
+  word-wrap: normal;
+  direction: ltr;
+}

static/vendor/htmx-sse.js

@@ -0,0 +1,322 @@
+/*
+Server Sent Events Extension
+============================
+This extension adds support for Server Sent Events to htmx.  See /www/extensions/sse.md for usage instructions.
+
+*/
+
+(function(){
+
+	/** @type {import("../htmx").HtmxInternalApi} */
+	var api;
+
+	htmx.defineExtension("sse", {
+
+		/**
+		 * Init saves the provided reference to the internal HTMX API.
+		 * 
+		 * @param {import("../htmx").HtmxInternalApi} api 
+		 * @returns void
+		 */
+		init: function(apiRef) {
+			// store a reference to the internal API.
+			api = apiRef;
+
+			// set a function in the public API for creating new EventSource objects
+			if (htmx.createEventSource == undefined) {
+				htmx.createEventSource = createEventSource;
+			}
+		},
+
+		/**
+		 * onEvent handles all events passed to this extension.
+		 * 
+		 * @param {string} name 
+		 * @param {Event} evt 
+		 * @returns void
+		 */
+		onEvent: function(name, evt) {
+
+			switch (name) {
+
+			// Try to remove remove an EventSource when elements are removed
+			case "htmx:beforeCleanupElement":
+				var internalData = api.getInternalData(evt.target)
+				if (internalData.sseEventSource) {
+					internalData.sseEventSource.close();
+				}
+				return;
+
+			// Try to create EventSources when elements are processed
+			case "htmx:afterProcessNode":
+				createEventSourceOnElement(evt.target);
+			}
+		}
+	});
+
+	///////////////////////////////////////////////
+	// HELPER FUNCTIONS
+	///////////////////////////////////////////////
+
+
+	/**
+	 * createEventSource is the default method for creating new EventSource objects.
+	 * it is hoisted into htmx.config.createEventSource to be overridden by the user, if needed.
+	 * 
+	 * @param {string} url 
+	 * @returns EventSource
+	 */
+	 function createEventSource(url) {
+		return new EventSource(url, {withCredentials:true});
+	}
+
+	function splitOnWhitespace(trigger) {
+		return trigger.trim().split(/\s+/);
+	}
+
+	function getLegacySSEURL(elt) {
+		var legacySSEValue = api.getAttributeValue(elt, "hx-sse");
+		if (legacySSEValue) {
+			var values = splitOnWhitespace(legacySSEValue);
+			for (var i = 0; i < values.length; i++) {
+				var value = values[i].split(/:(.+)/);
+				if (value[0] === "connect") {
+					return value[1];
+				}
+			}
+		}
+	}
+
+	function getLegacySSESwaps(elt) {
+		var legacySSEValue = api.getAttributeValue(elt, "hx-sse");
+		var returnArr = [];
+		if (legacySSEValue) {
+			var values = splitOnWhitespace(legacySSEValue);
+			for (var i = 0; i < values.length; i++) {
+				var value = values[i].split(/:(.+)/);
+				if (value[0] === "swap") {
+					returnArr.push(value[1]);
+				}
+			}
+		}
+		return returnArr;
+	}
+
+	/**
+	 * createEventSourceOnElement creates a new EventSource connection on the provided element.
+	 * If a usable EventSource already exists, then it is returned.  If not, then a new EventSource
+	 * is created and stored in the element's internalData.
+	 * @param {HTMLElement} elt
+	 * @param {number} retryCount
+	 * @returns {EventSource | null}
+	 */
+	function createEventSourceOnElement(elt, retryCount) {
+
+		if (elt == null) {
+			return null;
+		}
+
+		var internalData = api.getInternalData(elt);
+
+		// get URL from element's attribute
+		var sseURL = api.getAttributeValue(elt, "sse-connect");
+
+
+		if (sseURL == undefined) {
+			var legacyURL = getLegacySSEURL(elt)
+			if (legacyURL) {
+				sseURL = legacyURL;
+			} else {
+				return null;
+			}
+		}
+
+		// Connect to the EventSource
+		var source = htmx.createEventSource(sseURL);
+		internalData.sseEventSource = source;
+
+		// Create event handlers
+		source.onerror = function (err) {
+
+			// Log an error event
+			api.triggerErrorEvent(elt, "htmx:sseError", {error:err, source:source});
+
+			// If parent no longer exists in the document, then clean up this EventSource
+			if (maybeCloseSSESource(elt)) {
+				return;
+			}
+
+			// Otherwise, try to reconnect the EventSource
+			if (source.readyState === EventSource.CLOSED) {
+				retryCount = retryCount || 0;
+				var timeout = Math.random() * (2 ^ retryCount) * 500;
+				window.setTimeout(function() {
+					createEventSourceOnElement(elt, Math.min(7, retryCount+1));
+				}, timeout);
+			}			
+		};
+
+		source.onopen = function (evt) {
+			api.triggerEvent(elt, "htmx::sseOpen", {source: source});
+		}
+		
+		// Add message handlers for every `sse-swap` attribute
+		queryAttributeOnThisOrChildren(elt, "sse-swap").forEach(function(child) {
+
+			var sseSwapAttr = api.getAttributeValue(child, "sse-swap");
+			if (sseSwapAttr) {
+				var sseEventNames = sseSwapAttr.split(",");
+			} else {
+				var sseEventNames = getLegacySSESwaps(child);
+			}
+
+			for (var i = 0 ; i < sseEventNames.length ; i++) {
+				var sseEventName = sseEventNames[i].trim();
+				var listener = function(event) {
+
+					// If the parent is missing then close SSE and remove listener
+					if (maybeCloseSSESource(elt)) {
+						source.removeEventListener(sseEventName, listener);
+						return;
+					}
+
+					// swap the response into the DOM and trigger a notification
+					swap(child, event.data);
+					api.triggerEvent(elt, "htmx:sseMessage", event);
+				};
+
+				// Register the new listener
+				api.getInternalData(elt).sseEventListener = listener;
+				source.addEventListener(sseEventName, listener);
+			}
+		});
+
+		// Add message handlers for every `hx-trigger="sse:*"` attribute
+		queryAttributeOnThisOrChildren(elt, "hx-trigger").forEach(function(child) {
+
+			var sseEventName = api.getAttributeValue(child, "hx-trigger");
+			if (sseEventName == null) {
+				return;
+			}
+
+			// Only process hx-triggers for events with the "sse:" prefix
+			if (sseEventName.slice(0, 4) != "sse:") {
+				return;
+			}
+
+			var listener = function(event) {
+
+				// If parent is missing, then close SSE and remove listener
+				if (maybeCloseSSESource(elt)) {
+					source.removeEventListener(sseEventName, listener);
+					return;
+				}
+
+				// Trigger events to be handled by the rest of htmx
+				htmx.trigger(child, sseEventName, event);
+				htmx.trigger(child, "htmx:sseMessage", event);
+			}
+
+			// Register the new listener
+			api.getInternalData(elt).sseEventListener = listener;
+			source.addEventListener(sseEventName.slice(4), listener);
+		});
+	}
+
+	/**
+	 * maybeCloseSSESource confirms that the parent element still exists.
+	 * If not, then any associated SSE source is closed and the function returns true.
+	 * 
+	 * @param {HTMLElement} elt 
+	 * @returns boolean
+	 */
+	function maybeCloseSSESource(elt) {
+		if (!api.bodyContains(elt)) {
+			var source = api.getInternalData(elt).sseEventSource;
+			if (source != undefined) {
+				source.close();
+				// source = null
+				return true;
+			}
+		}
+		return false;
+	}
+
+	/**
+	 * queryAttributeOnThisOrChildren returns all nodes that contain the requested attributeName, INCLUDING THE PROVIDED ROOT ELEMENT.
+	 * 
+	 * @param {HTMLElement} elt 
+	 * @param {string} attributeName 
+	 */
+	function queryAttributeOnThisOrChildren(elt, attributeName) {
+
+		var result = [];
+
+		// If the parent element also contains the requested attribute, then add it to the results too.
+		if (api.hasAttribute(elt, attributeName) || api.hasAttribute(elt, "hx-sse")) {
+			result.push(elt);
+		}
+
+		// Search all child nodes that match the requested attribute
+		elt.querySelectorAll("[" + attributeName + "], [data-" + attributeName + "], [hx-sse], [data-hx-sse]").forEach(function(node) {
+			result.push(node);
+		});
+
+		return result;
+	}
+
+	/**
+	 * @param {HTMLElement} elt
+	 * @param {string} content 
+	 */
+	function swap(elt, content) {
+
+		api.withExtensions(elt, function(extension) {
+			content = extension.transformResponse(content, null, elt);
+		});
+
+		var swapSpec = api.getSwapSpecification(elt);
+		var target = api.getTarget(elt);
+		var settleInfo = api.makeSettleInfo(elt);
+
+		api.selectAndSwap(swapSpec.swapStyle, target, elt, content, settleInfo);
+
+		settleInfo.elts.forEach(function (elt) {
+			if (elt.classList) {
+				elt.classList.add(htmx.config.settlingClass);
+			}
+			api.triggerEvent(elt, 'htmx:beforeSettle');
+		});
+
+		// Handle settle tasks (with delay if requested)
+		if (swapSpec.settleDelay > 0) {
+			setTimeout(doSettle(settleInfo), swapSpec.settleDelay);
+		} else {
+			doSettle(settleInfo)();
+		}
+	}
+
+	/**
+	 * doSettle mirrors much of the functionality in htmx that 
+	 * settles elements after their content has been swapped.
+	 * TODO: this should be published by htmx, and not duplicated here
+	 * @param {import("../htmx").HtmxSettleInfo} settleInfo 
+	 * @returns () => void
+	 */
+	function doSettle(settleInfo) {
+
+		return function() {
+			settleInfo.tasks.forEach(function (task) {
+				task.call();
+			});
+
+			settleInfo.elts.forEach(function (elt) {
+				if (elt.classList) {
+					elt.classList.remove(htmx.config.settlingClass);
+				}
+				api.triggerEvent(elt, 'htmx:afterSettle');
+			});
+		}
+	}
+
+})();

templates/index.html

@@ -3,9 +3,11 @@
 <html>
   <head>
     <title>Empede</title>
-    <script src="https://unpkg.com/htmx.org@1.9.0" integrity="sha384-aOxz9UdWG0yBiyrTwPeMibmaoq07/d3a96GCbb9x60f3mOt5zwkjdbcHFnKH8qls" crossorigin="anonymous"></script>
-    <script src="https://unpkg.com/htmx.org/dist/ext/sse.js"></script>
-    <link rel="stylesheet" href="https://fonts.googleapis.com/css2?family=Material+Symbols+Outlined:opsz,wght,FILL,GRAD@48,400,1,0" />
+    
+    <!-- Source: https://github.com/bigskysoftware/htmx -->
+    <script src="/static/vendor/htmx.min.js"></script>
+    <script src="/static/vendor/htmx-sse.js"></script>
+
     <link rel="stylesheet" href="/static/style.css">
     <link href="/static/favicon.png" rel="icon" type="image/png">
   </head>