From 8e3936b14e4b450128dfde1e227c360da63f05ee Mon Sep 17 00:00:00 2001
From: MichaelWest22 <michael@latent.nz>
Date: Sat, 19 Jul 2025 01:02:29 +1200
Subject: [PATCH] add template wrapping support to ws extension

---
 src/ws/test/ext/ws.js | 34 ++++++++++++++++++++++++++++++++++
 src/ws/ws.js          | 24 ++++++++++++++++++------
 2 files changed, 52 insertions(+), 6 deletions(-)

diff --git a/src/ws/test/ext/ws.js b/src/ws/test/ext/ws.js
index 35bf6c7..cb9c7de 100644
--- a/src/ws/test/ext/ws.js
+++ b/src/ws/test/ext/ws.js
@@ -233,6 +233,40 @@ describe('web-sockets extension', function() {
     byId('d2').innerHTML.should.equal('div2')
   })
 
+
+  it('handles message from the server with template wrapping', function() {
+    var div = make('<div hx-ext="ws" ws-connect="ws://localhost:8080"><div id="d1">div1</div><div id="d2">div2</div><table><tr id="r3"><td>table</td></tr></Table></div>')
+    this.tickMock()
+
+    this.socketServer.emit('message', '<div id="d1">replaced</div><template><tr id="r3"><td>replaced</td></tr></template>')
+
+    this.tickMock()
+    byId('d1').innerHTML.should.equal('replaced')
+    byId('d2').innerHTML.should.equal('div2')
+    byId('r3').innerHTML.should.equal('<td>replaced</td>')
+  })
+
+  it('handles replacing template with id', function() {
+    var div = make('<div hx-ext="ws" ws-connect="ws://localhost:8080"><template id="t1">Template</template></div>')
+    this.tickMock()
+
+    this.socketServer.emit('message', '<template id="t1">replaced</template>')
+
+    this.tickMock()
+    byId('t1').innerHTML.should.equal('replaced')
+  })
+
+  it('handles replacing template with hx-swap-oob attribute', function() {
+    var div = make('<div hx-ext="ws" ws-connect="ws://localhost:8080"><template id="t1">Template</template></div>')
+    this.tickMock()
+
+    this.socketServer.emit('message', '<template hx-swap-oob="outerHTML:#t1">replaced</template>')
+
+    this.tickMock()
+
+    div.firstChild.innerHTML.should.equal('replaced')
+  })
+
   it('raises lifecycle events (connecting, open, close) in correct order', function() {
     var handledEventTypes = []
     var handler = function(evt) { handledEventTypes.push(evt.detail.event.type) }
diff --git a/src/ws/ws.js b/src/ws/ws.js
index 9ab33bd..a77c3cb 100644
--- a/src/ws/ws.js
+++ b/src/ws/ws.js
@@ -78,6 +78,23 @@ This extension adds support for WebSockets to htmx.  See /www/extensions/ws.md f
     }
   }
 
+  /**
+   * perform oobSwap on all fragment children and process children wrapped in empty template tags
+   * @param {HTMLCollection} children
+   * @param {Object} settleInfo
+   * @returns
+   */
+  function oobSwapChildren(children, settleInfo) {
+    for (const child of Array.from(children)) {
+      const hxSwapOob = api.getAttributeValue(child, 'hx-swap-oob')
+      if(child.tagName !== 'TEMPLATE' || hxSwapOob || child.id) {
+        api.oobSwap(hxSwapOob || 'true', child, settleInfo)
+      } else {
+        oobSwapChildren(child.content.children, settleInfo)
+      }
+    }
+  }
+
   /**
    * ensureWebSocket creates a new WebSocket on the designated element, using
    * the element's "ws-connect" attribute.
@@ -137,12 +154,7 @@ This extension adds support for WebSockets to htmx.  See /www/extensions/ws.md f
       var settleInfo = api.makeSettleInfo(socketElt)
       var fragment = api.makeFragment(response)
 
-      if (fragment.children.length) {
-        var children = Array.from(fragment.children)
-        for (var i = 0; i < children.length; i++) {
-          api.oobSwap(api.getAttributeValue(children[i], 'hx-swap-oob') || 'true', children[i], settleInfo)
-        }
-      }
+      oobSwapChildren(fragment.children, settleInfo)
 
       api.settleImmediately(settleInfo.tasks)
       api.triggerEvent(socketElt, 'htmx:wsAfterMessage', { message: response, socketWrapper: socketWrapper.publicInterface })