oob swap via extension fails if parent had [hx-swap]="outerHTML"

[anpin]

I'm using htmx 1.9.2 with htmx-signalr and it fails on this line

htmx/src/htmx.js

Line 948 in 990cdd6

newElt = parentElt(target).firstChild;

with

023-04-29T12:36:15.320Z] Error: A callback for the method 'component-update' threw error 'TypeError: Cannot read properties of null (reading 'firstChild')'.

If element received via signalr had hx-swap-oob="outerHTML" and some parent of the target had hx-swap="outerHTML"

For example with such layout:

<div hx-ext="signalr" signalr-connect="/hub" > 
 <div id="second-level" hx-swap="outerHTML"> 
   <div id="component" signalr-subscribe="component-update" hx-target="this" > <div/>
  <div/>
<div/>

When extension receives

   <div id="component" signalr-subscribe="component-update" hx-target="this" hx-swap-oob="outerHTML" >Some new content here<div/>

It replaces the content correctly, but then throws above exception after which any further updates would be ignored.

The workaround is to set hx-swap="innerhtml" on the target node in the original layout [1], so call to getSwapSpecification here returns innerhtml.

[1] Workaround

<div hx-ext="signalr" signalr-connect="/hub" > 
 <div id="second-level" hx-swap="outerHTML"> 
   <div id="component" signalr-subscribe="component-update" hx-target="this" hx-swap="innerhtml"> <div/>
  <div/>
<div/>

(Please let me know if the issue should be moved to the extension repo)

[Renerick]

Yes, hx-signalr is supported by me, not bigskysoftware, please move this issue to the repo, I'll take a look