arabica.social
Coffee journaling on ATProto (alpha)
alpha.arabica.social
coffee
fix: fix alpine issue on profile page
pdewey.com
+82
.skills/htmx-alpine-integration.md
+82
.skills/htmx-alpine-integration.md
···
1
+
# HTMX + Alpine.js Integration Pattern
2
+
3
+
## Problem: "Alpine Expression Error: [variable] is not defined"
4
+
5
+
When HTMX swaps in content containing Alpine.js directives (like `x-show`, `x-if`, `@click`), Alpine may not automatically process the new DOM elements, resulting in console errors like:
6
+
7
+
```
8
+
Alpine Expression Error: activeTab is not defined
9
+
Expression: "activeTab === 'brews'"
10
+
```
11
+
12
+
## Root Cause
13
+
14
+
HTMX loads and swaps content into the DOM after Alpine has already initialized. The new elements contain Alpine directives that reference variables in a parent Alpine component's scope, but Alpine doesn't automatically bind these new elements to the existing component.
15
+
16
+
## Solution
17
+
18
+
Use HTMX's `hx-on::after-swap` event to manually tell Alpine to initialize the new DOM tree:
19
+
20
+
```html
21
+
<div id="content"
22
+
hx-get="/api/data"
23
+
hx-trigger="load"
24
+
hx-swap="innerHTML"
25
+
hx-on::after-swap="Alpine.initTree($el)">
26
+
</div>
27
+
```
28
+
29
+
### Key Points
30
+
31
+
- `hx-on::after-swap` - HTMX event that fires after content swap completes
32
+
- `Alpine.initTree($el)` - Tells Alpine to process all directives in the swapped element
33
+
- `$el` - HTMX provides this as the target element that received the swap
34
+
35
+
## Common Scenario
36
+
37
+
**Parent template** (defines Alpine scope):
38
+
```html
39
+
<div x-data="{ activeTab: 'brews' }">
40
+
<!-- Static content with tab buttons -->
41
+
<button @click="activeTab = 'brews'">Brews</button>
42
+
43
+
<!-- HTMX loads dynamic content here -->
44
+
<div id="content"
45
+
hx-get="/api/tabs"
46
+
hx-trigger="load"
47
+
hx-swap="innerHTML"
48
+
hx-on::after-swap="Alpine.initTree($el)">
49
+
</div>
50
+
</div>
51
+
```
52
+
53
+
**Loaded partial** (uses parent scope):
54
+
```html
55
+
<div x-show="activeTab === 'brews'">
56
+
<!-- Brew content -->
57
+
</div>
58
+
<div x-show="activeTab === 'beans'">
59
+
<!-- Bean content -->
60
+
</div>
61
+
```
62
+
63
+
Without `Alpine.initTree($el)`, the `x-show` directives won't be bound to the parent's `activeTab` variable.
64
+
65
+
## Alternative: Alpine Morph Plugin
66
+
67
+
For more complex scenarios with nested Alpine components, use the Alpine Morph plugin:
68
+
69
+
```html
70
+
<script src="https://cdn.jsdelivr.net/npm/@alpinejs/morph@3.x.x/dist/cdn.min.js"></script>
71
+
<div hx-swap="morph"></div>
72
+
```
73
+
74
+
This preserves Alpine state during swaps but requires the plugin.
75
+
76
+
## When to Use
77
+
78
+
Apply this pattern whenever:
79
+
1. HTMX loads content containing Alpine directives
80
+
2. The loaded content references variables from a parent Alpine component
81
+
3. You see "Expression Error: [variable] is not defined" in console
82
+
4. Alpine directives in HTMX-loaded content don't work (no reactivity, clicks ignored, etc.)
+2
-5
justfile
+2
-5
justfile
···
1
1
run:
2
-
@LOG_LEVEL=debug LOG_FORMAT=console go run cmd/server/main.go
2
+
@LOG_LEVEL=debug LOG_FORMAT=console go run cmd/server/main.go -firehose
3
3
4
4
run-production:
5
-
@LOG_FORMAT=json SECURE_COOKIES=true go run cmd/server/main.go
6
-
7
-
run-firehose:
8
-
@LOG_LEVEL=debug LOG_FORMAT=console go run cmd/server/main.go -firehose
5
+
@LOG_FORMAT=json SECURE_COOKIES=true go run cmd/server/main.go -firehose
9
6
10
7
test:
11
8
@go test ./... -cover -coverprofile=cover.out
+1
-1
templates/profile.tmpl
+1
-1
templates/profile.tmpl
···
87
87
</div>
88
88
89
89
<!-- Tab content loaded via HTMX -->
90
-
<div id="profile-content" hx-get="/api/profile/{{.Profile.Handle}}" hx-trigger="load" hx-swap="innerHTML">
90
+
<div id="profile-content" hx-get="/api/profile/{{.Profile.Handle}}" hx-trigger="load" hx-swap="innerHTML" hx-on::after-swap="Alpine.initTree($el)">
91
91
<!-- Loading skeleton -->
92
92
<div class="animate-pulse">
93
93
<!-- Brews Tab Skeleton -->