Module for HTMX SSE extension

.gitignore

@@ -7,3 +7,5 @@ DerivedData/
 .swiftpm/xcode/package.xcworkspace/contents.xcworkspacedata
 .netrc
 Package.resolved
+/.vscode
+/.devcontainer

Examples/HummingbirdDemo/Package.swift

@@ -13,6 +13,8 @@ let package = Package(
         .package(url: "https://github.com/hummingbird-project/hummingbird.git", from: "2.0.0-rc.1"),
         .package(url: "https://github.com/hummingbird-community/hummingbird-elementary.git", from: "0.1.0-rc.1"),
         .package(path: "../../"),
+        .package(url: "https://github.com/apple/swift-async-algorithms", from: "1.0.0"),
+        .package(url: "https://github.com/swift-server/swift-service-lifecycle.git", from: "2.0.0"),
     ],
     targets: [
         .executableTarget(
@@ -21,6 +23,9 @@ let package = Package(
                 .product(name: "Hummingbird", package: "hummingbird"),
                 .product(name: "HummingbirdElementary", package: "hummingbird-elementary"),
                 .product(name: "ElementaryHTMX", package: "elementary-htmx"),
+                .product(name: "ElementaryHTMXSSE", package: "elementary-htmx"),
+                .product(name: "AsyncAlgorithms", package: "swift-async-algorithms"),
+                .product(name: "ServiceLifecycle", package: "swift-service-lifecycle"),
             ],
             resources: [
                 .copy("Public"),

Examples/HummingbirdDemo/Sources/App/ElementaryHTMXSSE+Hummingbird.swift

@@ -0,0 +1,17 @@
+import Elementary
+import Hummingbird
+import HummingbirdElementary
+import ServiceLifecycle
+
+public extension Response {
+    static func stream<BufferSequence: AsyncSequence & Sendable>(_ asyncSequence: BufferSequence) -> Response where BufferSequence.Element == ByteBuffer {
+        .init(status: .ok, headers: [.contentType: "text/event-stream"], body: .init(asyncSequence: asyncSequence.cancelOnGracefulShutdown()))
+    }
+
+    static func stream<BufferSequence: AsyncSequence & Sendable>(_ asyncSequence: BufferSequence, eventName: String? = nil) -> Response where BufferSequence.Element: HTML {
+        let eventStream = asyncSequence.map { html in
+            ByteBuffer(bytes: "\(eventName != nil ? "event:\(eventName!)\n" : "")data:\(html.render())\n\n".utf8)
+        }
+        return .stream(eventStream)
+    }
+}

Examples/HummingbirdDemo/Sources/App/Public/htmxsse.min.js

@@ -0,0 +1,121 @@
+!(function () {
+  var e;
+  function t(e) {
+    return new EventSource(e, { withCredentials: !0 });
+  }
+  function n(t) {
+    if (!e.bodyContains(t)) {
+      var n = e.getInternalData(t).sseEventSource;
+      if (null != n) return n.close(), !0;
+    }
+    return !1;
+  }
+  function r(t, n) {
+    var r = [];
+    return (
+      e.hasAttribute(t, n) && r.push(t),
+      t.querySelectorAll('[' + n + '], [data-' + n + ']').forEach(function (e) {
+        r.push(e);
+      }),
+      r
+    );
+  }
+  function s(t, n) {
+    e.withExtensions(t, function (e) {
+      n = e.transformResponse(n, null, t);
+    });
+    var r = e.getSwapSpecification(t),
+      s = e.getTarget(t);
+    e.swap(s, n, r);
+  }
+  function a(t) {
+    return null != e.getInternalData(t).sseEventSource;
+  }
+  htmx.defineExtension('sse', {
+    init: function (n) {
+      (e = n), null == htmx.createEventSource && (htmx.createEventSource = t);
+    },
+    onEvent: function (t, o) {
+      var i = o.target || o.detail.elt;
+      switch (t) {
+        case 'htmx:beforeCleanupElement':
+          var u = e.getInternalData(i);
+          return void (u.sseEventSource && u.sseEventSource.close());
+        case 'htmx:afterProcessNode':
+          !(function t(o, i) {
+            var u;
+            if (null == o) return null;
+            r(o, 'sse-connect').forEach(function (r) {
+              var s,
+                a,
+                o,
+                u,
+                c = e.getAttributeValue(r, 'sse-connect');
+              null != c &&
+                ((s = r),
+                (a = c),
+                (o = i),
+                ((u = htmx.createEventSource(a)).onerror = function (r) {
+                  if (
+                    (e.triggerErrorEvent(s, 'htmx:sseError', {
+                      error: r,
+                      source: u,
+                    }),
+                    !n(s) && u.readyState === EventSource.CLOSED)
+                  ) {
+                    var a = Math.random() * (2 ^ (o = o || 0)) * 500;
+                    window.setTimeout(function () {
+                      t(s, Math.min(7, o + 1));
+                    }, a);
+                  }
+                }),
+                (u.onopen = function (t) {
+                  e.triggerEvent(s, 'htmx:sseOpen', { source: u });
+                }),
+                (e.getInternalData(s).sseEventSource = u));
+            }),
+              r((u = o), 'sse-swap').forEach(function (t) {
+                var r = e.getClosestMatch(t, a);
+                if (null == r) return null;
+                for (
+                  var o = e.getInternalData(r).sseEventSource,
+                    i = e.getAttributeValue(t, 'sse-swap').split(','),
+                    c = 0;
+                  c < i.length;
+                  c++
+                ) {
+                  var l = i[c].trim(),
+                    v = function (a) {
+                      if (!n(r)) {
+                        if (!e.bodyContains(t))
+                          return void o.removeEventListener(l, v);
+                        e.triggerEvent(u, 'htmx:sseBeforeMessage', a) &&
+                          (s(t, a.data),
+                          e.triggerEvent(u, 'htmx:sseMessage', a));
+                      }
+                    };
+                  (e.getInternalData(t).sseEventListener = v),
+                    o.addEventListener(l, v);
+                }
+              }),
+              r(u, 'hx-trigger').forEach(function (t) {
+                var r = e.getClosestMatch(t, a);
+                if (null == r) return null;
+                var s = e.getInternalData(r).sseEventSource,
+                  o = e.getAttributeValue(t, 'hx-trigger');
+                if (null != o && 'sse:' == o.slice(0, 4)) {
+                  var i = function (a) {
+                    !n(r) &&
+                      (e.bodyContains(t) || s.removeEventListener(o, i),
+                      htmx.trigger(t, o, a),
+                      htmx.trigger(t, 'htmx:sseMessage', a));
+                  };
+                  (e.getInternalData(u).sseEventListener = i),
+                    s.addEventListener(o.slice(4), i);
+                }
+              });
+          })(i);
+      }
+    },
+  });
+})();

Examples/HummingbirdDemo/Sources/App/Routes.swift

@@ -1,3 +1,4 @@
+import AsyncAlgorithms
 import Hummingbird
 import HummingbirdElementary
 
@@ -10,6 +11,14 @@ func addRoutes(to router: Router<some RequestContext>) {
         }
     }
 
+    router.get("/time") { _, _ in
+        let timerSequence = AsyncTimerSequence(interval: .seconds(1), clock: ContinuousClock())
+            .map { _ in
+                TimeHeading()
+            }
+        return Response.stream(timerSequence, eventName: "time")
+    }
+
     router.post("/items") { request, context in
         let body = try await request.decode(as: AddItemRequest.self, context: context)
         await Database.shared.addItem(body.item)
@@ -44,3 +53,8 @@ func addRoutes(to router: Router<some RequestContext>) {
 struct AddItemRequest: Decodable {
     var item: String
 }
+
+struct Event: Encodable {
+    var event: String
+    var data: String
+}

Examples/HummingbirdDemo/Sources/App/Views.swift

@@ -1,20 +1,27 @@
 import Elementary
-import ElementaryHTMX
+import ElementaryHTMXSSE
+import Foundation
 
 struct MainPage: HTMLDocument {
-    var title: String { "Hummingbird + Elementary + HTMX" }
+    var title: String { "Hummingbird + Elementary + HTMX + HTMX SSE" }
 
     var model: Model
 
     var head: some HTML {
         meta(.charset(.utf8))
         script(.src("/htmx.min.js")) {}
+        script(.src("/htmxsse.min.js")) {}
         link(.href("/pico.min.css"), .rel(.stylesheet))
     }
 
     var body: some HTML {
         header(.class("container")) {
-            h2 { "Hummingbird + Elementary + HTMX Demo" }
+            h2 { "Hummingbird + Elementary + HTMX + HTMX SSE Demo" }
+            div(.hx.ext(.sse), .sse.connect("/time"), .sse.swap("time")) {
+                h4 {
+                    "Server Time: \(Date())"
+                }
+            }
         }
         main(.class("container")) {
             div {
@@ -50,3 +57,11 @@ struct ItemList: HTML {
         }
     }
 }
+
+struct TimeHeading: HTML {
+    var content: some HTML<HTMLTag.h4> {
+        h4 {
+            "Server Time: \(Date())"
+        }
+    }
+}

Examples/VaporDemo/Package.swift

@@ -13,6 +13,7 @@ let package = Package(
         .package(url: "https://github.com/vapor/vapor", from: "4.102.0"),
         .package(url: "https://github.com/vapor-community/vapor-elementary.git", from: "0.1.0"),
         .package(path: "../../"),
+        .package(url: "https://github.com/apple/swift-async-algorithms", from: "1.0.0"),
     ],
     targets: [
         .executableTarget(
@@ -21,6 +22,8 @@ let package = Package(
                 .product(name: "Vapor", package: "vapor"),
                 .product(name: "VaporElementary", package: "vapor-elementary"),
                 .product(name: "ElementaryHTMX", package: "elementary-htmx"),
+                .product(name: "ElementaryHTMXSSE", package: "elementary-htmx"),
+                .product(name: "AsyncAlgorithms", package: "swift-async-algorithms"),
             ],
             resources: [
                 .copy("Public"),

Examples/VaporDemo/Sources/App/Public/htmxsse.min.js

@@ -0,0 +1,121 @@
+!(function () {
+  var e;
+  function t(e) {
+    return new EventSource(e, { withCredentials: !0 });
+  }
+  function n(t) {
+    if (!e.bodyContains(t)) {
+      var n = e.getInternalData(t).sseEventSource;
+      if (null != n) return n.close(), !0;
+    }
+    return !1;
+  }
+  function r(t, n) {
+    var r = [];
+    return (
+      e.hasAttribute(t, n) && r.push(t),
+      t.querySelectorAll('[' + n + '], [data-' + n + ']').forEach(function (e) {
+        r.push(e);
+      }),
+      r
+    );
+  }
+  function s(t, n) {
+    e.withExtensions(t, function (e) {
+      n = e.transformResponse(n, null, t);
+    });
+    var r = e.getSwapSpecification(t),
+      s = e.getTarget(t);
+    e.swap(s, n, r);
+  }
+  function a(t) {
+    return null != e.getInternalData(t).sseEventSource;
+  }
+  htmx.defineExtension('sse', {
+    init: function (n) {
+      (e = n), null == htmx.createEventSource && (htmx.createEventSource = t);
+    },
+    onEvent: function (t, o) {
+      var i = o.target || o.detail.elt;
+      switch (t) {
+        case 'htmx:beforeCleanupElement':
+          var u = e.getInternalData(i);
+          return void (u.sseEventSource && u.sseEventSource.close());
+        case 'htmx:afterProcessNode':
+          !(function t(o, i) {
+            var u;
+            if (null == o) return null;
+            r(o, 'sse-connect').forEach(function (r) {
+              var s,
+                a,
+                o,
+                u,
+                c = e.getAttributeValue(r, 'sse-connect');
+              null != c &&
+                ((s = r),
+                (a = c),
+                (o = i),
+                ((u = htmx.createEventSource(a)).onerror = function (r) {
+                  if (
+                    (e.triggerErrorEvent(s, 'htmx:sseError', {
+                      error: r,
+                      source: u,
+                    }),
+                    !n(s) && u.readyState === EventSource.CLOSED)
+                  ) {
+                    var a = Math.random() * (2 ^ (o = o || 0)) * 500;
+                    window.setTimeout(function () {
+                      t(s, Math.min(7, o + 1));
+                    }, a);
+                  }
+                }),
+                (u.onopen = function (t) {
+                  e.triggerEvent(s, 'htmx:sseOpen', { source: u });
+                }),
+                (e.getInternalData(s).sseEventSource = u));
+            }),
+              r((u = o), 'sse-swap').forEach(function (t) {
+                var r = e.getClosestMatch(t, a);
+                if (null == r) return null;
+                for (
+                  var o = e.getInternalData(r).sseEventSource,
+                    i = e.getAttributeValue(t, 'sse-swap').split(','),
+                    c = 0;
+                  c < i.length;
+                  c++
+                ) {
+                  var l = i[c].trim(),
+                    v = function (a) {
+                      if (!n(r)) {
+                        if (!e.bodyContains(t))
+                          return void o.removeEventListener(l, v);
+                        e.triggerEvent(u, 'htmx:sseBeforeMessage', a) &&
+                          (s(t, a.data),
+                          e.triggerEvent(u, 'htmx:sseMessage', a));
+                      }
+                    };
+                  (e.getInternalData(t).sseEventListener = v),
+                    o.addEventListener(l, v);
+                }
+              }),
+              r(u, 'hx-trigger').forEach(function (t) {
+                var r = e.getClosestMatch(t, a);
+                if (null == r) return null;
+                var s = e.getInternalData(r).sseEventSource,
+                  o = e.getAttributeValue(t, 'hx-trigger');
+                if (null != o && 'sse:' == o.slice(0, 4)) {
+                  var i = function (a) {
+                    !n(r) &&
+                      (e.bodyContains(t) || s.removeEventListener(o, i),
+                      htmx.trigger(t, o, a),
+                      htmx.trigger(t, 'htmx:sseMessage', a));
+                  };
+                  (e.getInternalData(u).sseEventListener = i),
+                    s.addEventListener(o.slice(4), i);
+                }
+              });
+          })(i);
+      }
+    },
+  });
+})();