✨ multi-image comics

CLAUDE.md

@@ -43,9 +43,9 @@ Run this after adding/updating comics to regenerate `static/sitemap.xml` for sea
 ### Data Layer: comics_data.py
 Comics are stored as a Python list called `COMICS`. Each comic is a dictionary with:
 - `number` (required): Sequential comic number
-- `filename` (required): Image filename in `static/images/comics/`
+- `filename` (required): Image filename in `static/images/comics/` OR list of filenames for multi-image comics (webtoon style)
 - `date` (required): Publication date in YYYY-MM-DD format
-- `alt_text` (required): Accessibility text
+- `alt_text` (required): Accessibility text OR list of alt texts (one per image for multi-image comics)
 - `title` (optional): Comic title (defaults to "#X" if absent)
 - `author_note` (optional): Plain text note
 - `author_note_md` (optional): Markdown file for author note (just filename like "2025-01-01.md" looks in `content/author_notes/`, or path like "special/note.md" relative to `content/`). Takes precedence over `author_note`.
@@ -53,6 +53,16 @@ Comics are stored as a Python list called `COMICS`. Each comic is a dictionary w
 - `plain` (optional): Override global PLAIN_DEFAULT setting (hides header/border)
 - `section` (optional): Section/chapter title (e.g., "Chapter 1: Origins"). Add to first comic of a new section.
 
+**Multi-image comics (webtoon style):**
+- Set `filename` to a list of image filenames: `['page1.png', 'page2.png', 'page3.png']`
+- Set `alt_text` to either:
+  - A single string (applies to all images): `'A three-part vertical story'`
+  - A list matching each image: `['Description 1', 'Description 2', 'Description 3']`
+- If `alt_text` is a list but doesn't match `filename` length, a warning is logged
+- Images display vertically with seamless stacking (no gaps)
+- First image loads immediately; subsequent images lazy-load as user scrolls
+- No click-through navigation on multi-image comics (use navigation buttons instead)
+
 Global configuration in `comics_data.py`:
 - `COMIC_NAME`: Your comic/website name
 - `COPYRIGHT_NAME`: Name to display in copyright notice (defaults to COMIC_NAME if not set)

README.md

@@ -158,6 +158,7 @@ Don't have a server? No problem! Here are beginner-friendly options to get your
 ## Features
 
 - Comic viewer with navigation (First, Previous, Next, Latest)
+- **Multi-image comics** with vertical scrolling (webtoon style) and lazy loading
 - Client-side navigation using JSON API (no page reloads)
 - Keyboard navigation support (arrow keys, Home/End)
 - Archive page with thumbnail grid
@@ -732,10 +733,10 @@ Comics are stored in the `COMICS` list in `comics_data.py`. Each comic entry:
 ```python
 {
     'number': 1,                           # Comic number (required, sequential)
-    'filename': 'comic-001.png',           # Image filename (required)
+    'filename': 'comic-001.png',           # Image filename (required) OR list for multi-image
-    'mobile_filename': 'comic-001-mobile.png',  # Optional mobile version
+    'mobile_filename': 'comic-001-mobile.png',  # Optional mobile version (single-image only)
     'date': '2025-01-01',                  # Publication date (required)
-    'alt_text': 'Alt text for comic',      # Accessibility text (required)
+    'alt_text': 'Alt text for comic',      # Accessibility text (required) OR list for multi-image
     'title': 'Comic Title',                # Title (optional, shows #X if absent)
     'author_note': 'Optional note',        # Author note (optional, plain text)
     'author_note_md': '2025-01-01.md',     # Optional markdown file for author note
@@ -744,6 +745,17 @@ Comics are stored in the `COMICS` list in `comics_data.py`. Each comic entry:
 }
 ```
 
+**For multi-image comics (webtoon style):**
+```python
+{
+    'number': 2,
+    'filename': ['page1.png', 'page2.png', 'page3.png'],  # List of images
+    'alt_text': ['Panel 1 description', 'Panel 2', 'Panel 3'],  # Individual alt texts
+    'date': '2025-01-08',
+    'full_width': True  # Recommended for webtoons
+}
+```
+
 ### Adding a New Comic
 
 **Option 1: Use the script (recommended)**
@@ -800,6 +812,102 @@ The `/about` route renders `content/about.md` as HTML. Edit this file to customi
 
 **Note:** Client-side navigation displays author notes as plain text. Markdown author notes only render properly on initial page load (server-side rendering). For full markdown rendering, users need to refresh the page or navigate directly to the comic URL.
 
+### Multi-Image Comics (Webtoon Style)
+
+Sunday Comics supports vertical scrolling comics with multiple images stacked seamlessly, perfect for webtoon-style storytelling.
+
+**How it works:**
+- Set `filename` to a list of image filenames instead of a single string
+- Images display vertically with no gaps between them
+- First image loads immediately, subsequent images lazy-load as readers scroll
+- No click-through navigation on multi-image comics (use navigation buttons instead)
+
+**Basic Example:**
+```python
+# In comics_data.py
+{
+    'number': 4,
+    'title': 'Webtoon Episode 1',
+    'filename': ['page1.jpg', 'page2.jpg', 'page3.jpg'],  # List of images
+    'alt_text': 'A three-part vertical story',  # Single alt text for all images
+    'date': '2025-01-22',
+}
+```
+
+**Individual Alt Text (Recommended for Accessibility):**
+```python
+{
+    'number': 5,
+    'title': 'Long Scroll Episode',
+    'filename': ['scene1.png', 'scene2.png', 'scene3.png', 'scene4.png'],
+    'alt_text': [
+        'Opening scene showing the city at dawn',
+        'Character walking through the marketplace',
+        'Close-up of the mysterious artifact',
+        'Dramatic reveal of the antagonist'
+    ],  # List must match number of images (or use single string for all)
+    'date': '2025-01-29',
+}
+```
+
+**Important:** If you provide `alt_text` as a list, it should match the number of images in `filename`. If the counts don't match, you'll see a warning in the logs. To use the same alt text for all images, just provide a single string instead of a list.
+
+**Features:**
+- ✅ **Seamless vertical layout** - Images stack with no visible gaps
+- ✅ **Lazy loading** - Only loads images as they scroll into view (performance optimization)
+- ✅ **Responsive** - Works on desktop and mobile devices
+- ✅ **Accessible** - Supports individual alt text for each image panel
+- ✅ **Backward compatible** - Single-image comics continue to work as before
+
+**Best Practices:**
+1. **Image consistency** - Use the same width for all images in a multi-image comic for best results
+2. **Alt text per panel** - Provide individual alt text for each image to describe what's happening in that section
+3. **File naming** - Use descriptive, sequential names like `comic-004-panel-1.png`, `comic-004-panel-2.png`
+4. **Image optimization** - Compress images appropriately since readers will load multiple images per comic
+
+**Example with all options:**
+```python
+{
+    'number': 6,
+    'title': 'Chapter 2: The Journey Begins',
+    'filename': [
+        'ch2-001.png',
+        'ch2-002.png',
+        'ch2-003.png',
+        'ch2-004.png',
+        'ch2-005.png'
+    ],
+    'alt_text': [
+        'Panel 1: Hero packs their bag at sunrise',
+        'Panel 2: Saying goodbye to the village elder',
+        'Panel 3: Walking along the forest path',
+        'Panel 4: Encountering a mysterious stranger',
+        'Panel 5: Accepting a map to the ancient ruins'
+    ],
+    'date': '2025-02-05',
+    'author_note': 'This was so much fun to draw! The journey arc begins.',
+    'full_width': True,  # Recommended for webtoon-style comics
+    'section': 'Chapter 2',  # Optional: mark the start of a new chapter
+}
+```
+
+**Technical Details:**
+- Images appear in the order listed in the `filename` array
+- If `alt_text` is a single string, it applies to all images
+- If `alt_text` is a list, it must match the length of `filename` (or it will pad with empty strings)
+- The first image in the array is used as the thumbnail in the archive page
+- Lazy loading uses Intersection Observer API with 50px margin for smooth loading
+
+**When to use multi-image:**
+- Long-form vertical scrolling stories (webtoons, manhwa style)
+- Comics with natural panel breaks across multiple images
+- Stories that benefit from vertical pacing and reveals
+
+**When to stick with single images:**
+- Traditional comic strip or page layouts
+- Self-contained single-panel comics
+- When you want click-through navigation on the comic image
+
 ## Production Deployment
 
 For production, you should **NOT** use Flask's built-in development server. Choose one of the following deployment methods:

app.py

@@ -3,6 +3,7 @@
 # Licensed under the MIT License - see LICENSE file for details
 
 import os
+import logging
 from datetime import datetime
 from flask import Flask, render_template, abort, jsonify, request
 from comics_data import (
@@ -13,6 +14,10 @@ from comics_data import (
 )
 import markdown
 
+# Configure logging
+logging.basicConfig(level=logging.WARNING)
+logger = logging.getLogger(__name__)
+
 app = Flask(__name__)
 
 # Configuration
@@ -117,6 +122,47 @@ def enrich_comic(comic):
     enriched['plain'] = is_plain(comic)
     enriched['formatted_date'] = format_comic_date(comic['date'])
 
+    # Normalize filename to list for multi-image support
+    if isinstance(comic.get('filename'), list):
+        enriched['filenames'] = comic['filename']
+        enriched['is_multi_image'] = True
+    else:
+        enriched['filenames'] = [comic['filename']] if 'filename' in comic else []
+        enriched['is_multi_image'] = False
+
+    # Normalize alt_text to list matching filenames
+    if isinstance(comic.get('alt_text'), list):
+        enriched['alt_texts'] = comic['alt_text']
+
+        # Warn if alt_text list doesn't match filenames length
+        if len(enriched['alt_texts']) != len(enriched['filenames']):
+            logger.warning(
+                f"Comic #{comic['number']}: alt_text list length ({len(enriched['alt_texts'])}) "
+                f"doesn't match filenames length ({len(enriched['filenames'])}). "
+                f"Tip: Use a single string for alt_text to apply the same text to all images, "
+                f"or provide a list matching the number of images."
+            )
+    else:
+        # If single alt_text string, use it for all images (this is intentional and valid)
+        alt_text = comic.get('alt_text', '')
+        enriched['alt_texts'] = [alt_text] * len(enriched['filenames'])
+
+    # Ensure alt_texts list matches filenames length (pad with empty strings if too short)
+    while len(enriched['alt_texts']) < len(enriched['filenames']):
+        enriched['alt_texts'].append('')
+
+    # Trim alt_texts if too long (extra ones won't be used anyway)
+    if len(enriched['alt_texts']) > len(enriched['filenames']):
+        enriched['alt_texts'] = enriched['alt_texts'][:len(enriched['filenames'])]
+
+    # Keep original filename and alt_text for backward compatibility (first image)
+    if enriched['filenames']:
+        enriched['filename'] = enriched['filenames'][0]
+
+    # Ensure alt_text is always a string (use first one if it's a list)
+    if enriched['alt_texts']:
+        enriched['alt_text'] = enriched['alt_texts'][0]
+
     # Check for explicitly specified markdown author note file
     if 'author_note_md' in comic and comic['author_note_md']:
         markdown_note = get_author_note_from_file(comic['author_note_md'])

static/css/style.css

@@ -431,6 +431,30 @@ main {
     margin: 0 auto;
 }
 
+/* Multi-image comics (webtoon style) */
+.comic-image-multi {
+    padding: 0; /* Remove padding for seamless stacking */
+}
+
+.comic-image-multi img {
+    display: block;
+    width: 100%;
+    margin: 0;
+    padding: 0;
+    vertical-align: bottom; /* Removes tiny gap below images */
+}
+
+/* Lazy-loaded images - placeholder while loading */
+.comic-image-multi img.lazy-load {
+    min-height: 200px;
+    background: var(--color-hover-bg);
+}
+
+.comic-image-multi img.lazy-load.loaded {
+    min-height: auto;
+    background: none;
+}
+
 /* Comic Navigation */
 .comic-navigation {
     border-top: var(--border-width-thin) solid var(--border-color);

static/js/comic-nav.js

@@ -5,6 +5,7 @@
     let totalComics = 0;
     let comicName = '';  // Will be extracted from initial page title
     let currentComicNumber = 0;
+    let lazyLoadObserver = null;
 
     // Fetch and display a comic
     async function loadComic(comicId) {
@@ -79,8 +80,15 @@
         const comicImageDiv = document.querySelector('.comic-image');
         updateComicImage(comicImageDiv, comic, title);
 
-        // Update or create/remove the link wrapper
+        // Update or create/remove the link wrapper (only for single-image comics)
+        if (!comic.is_multi_image) {
             updateComicImageLink(comic.number);
+        }
+
+        // Initialize lazy loading for multi-image comics
+        if (comic.is_multi_image) {
+            initLazyLoad();
+        }
 
         // Update author note
         let transcriptDiv = document.querySelector('.comic-transcript');
@@ -137,12 +145,72 @@
         }
     }
 
+    // Initialize lazy loading for multi-image comics
+    function initLazyLoad() {
+        // Disconnect existing observer if any
+        if (lazyLoadObserver) {
+            lazyLoadObserver.disconnect();
+        }
+
+        // Create Intersection Observer for lazy loading
+        lazyLoadObserver = new IntersectionObserver((entries) => {
+            entries.forEach(entry => {
+                if (entry.isIntersecting) {
+                    const img = entry.target;
+                    const src = img.getAttribute('data-src');
+                    if (src) {
+                        img.src = src;
+                        img.removeAttribute('data-src');
+                        img.classList.add('loaded');
+                        lazyLoadObserver.unobserve(img);
+                    }
+                }
+            });
+        }, {
+            rootMargin: '50px' // Start loading 50px before image enters viewport
+        });
+
+        // Observe all lazy-load images
+        document.querySelectorAll('.lazy-load').forEach(img => {
+            lazyLoadObserver.observe(img);
+        });
+    }
+
     // Update or create comic image with optional mobile version
     function updateComicImage(comicImageDiv, comic, title) {
         // Clear all existing content
         comicImageDiv.innerHTML = '';
 
+        // Update container class for multi-image
+        if (comic.is_multi_image) {
+            comicImageDiv.classList.add('comic-image-multi');
+        } else {
+            comicImageDiv.classList.remove('comic-image-multi');
+        }
+
         // Create new image element(s)
+        if (comic.is_multi_image) {
+            // Multi-image comic (webtoon style)
+            comic.filenames.forEach((filename, index) => {
+                const img = document.createElement('img');
+
+                if (index === 0) {
+                    // First image loads immediately
+                    img.src = `/static/images/comics/${filename}`;
+                    img.loading = 'eager';
+                } else {
+                    // Subsequent images lazy load
+                    img.setAttribute('data-src', `/static/images/comics/${filename}`);
+                    img.classList.add('lazy-load');
+                    img.loading = 'lazy';
+                }
+
+                img.alt = comic.alt_texts[index] || '';
+                img.title = comic.alt_texts[index] || '';
+                comicImageDiv.appendChild(img);
+            });
+        } else {
+            // Single image comic
             if (comic.mobile_filename) {
                 // Create picture element with mobile source
                 const picture = document.createElement('picture');
@@ -168,6 +236,7 @@
                 comicImageDiv.appendChild(img);
             }
         }
+    }
 
     // Update comic image link for click navigation
     function updateComicImageLink(currentNumber) {
@@ -377,7 +446,17 @@
             const dateDisplay = document.querySelector('.comic-date-display');
             const formattedDate = dateDisplay ? dateDisplay.textContent : null;
             updateNavButtons(currentNumber, formattedDate);
+
+            // Check if current comic is multi-image
+            const comicImageDiv = document.querySelector('.comic-image');
+            const isMultiImage = comicImageDiv && comicImageDiv.classList.contains('comic-image-multi');
+
+            if (!isMultiImage) {
                 updateComicImageLink(currentNumber);
+            } else {
+                // Initialize lazy loading for multi-image comics on page load
+                initLazyLoad();
+            }
         }
 
         // Handle browser back/forward

templates/comic.html

@@ -37,7 +37,18 @@
     </div>
     {% endif %}
 
-    <div class="comic-image" id="comic-image-focus" tabindex="-1">
+    <div class="comic-image{% if comic.is_multi_image %} comic-image-multi{% endif %}" id="comic-image-focus" tabindex="-1">
+        {% if comic.is_multi_image %}
+            {# Multi-image layout (webtoon style) - no click-through on individual images #}
+            {% for i in range(comic.filenames|length) %}
+            <img src="{% if loop.first %}{{ url_for('static', filename='images/comics/' + comic.filenames[i]) }}{% endif %}"
+                 {% if not loop.first %}data-src="{{ url_for('static', filename='images/comics/' + comic.filenames[i]) }}" class="lazy-load"{% endif %}
+                 alt="{{ comic.alt_texts[i] }}"
+                 title="{{ comic.alt_texts[i] }}"
+                 loading="{% if loop.first %}eager{% else %}lazy{% endif %}">
+            {% endfor %}
+        {% else %}
+            {# Single image with click-through to next comic #}
             {% if comic.number < total_comics %}
             <a href="{{ url_for('comic', comic_id=comic.number + 1) }}" aria-label="Click to view next comic">
                 {% if comic.mobile_filename %}
@@ -69,6 +80,7 @@
                      loading="eager">
                 {% endif %}
             {% endif %}
+        {% endif %}
     </div>
 
     <div class="comic-navigation">

templates/index.html

@@ -16,7 +16,17 @@
         <p class="comic-date">{{ comic.date }}</p>
     </div>
 
-    <div class="comic-image" id="comic-image-focus" tabindex="-1">
+    <div class="comic-image{% if comic.is_multi_image %} comic-image-multi{% endif %}" id="comic-image-focus" tabindex="-1">
+        {% if comic.is_multi_image %}
+            {# Multi-image layout (webtoon style) - no click-through on individual images #}
+            {% for i in range(comic.filenames|length) %}
+            <img src="{% if loop.first %}{{ url_for('static', filename='images/comics/' + comic.filenames[i]) }}{% endif %}"
+                 {% if not loop.first %}data-src="{{ url_for('static', filename='images/comics/' + comic.filenames[i]) }}" class="lazy-load"{% endif %}
+                 alt="{{ comic.alt_texts[i] }}"
+                 title="{{ comic.alt_texts[i] }}"
+                 loading="{% if loop.first %}eager{% else %}lazy{% endif %}">
+            {% endfor %}
+        {% else %}
             {% if comic.mobile_filename %}
             <picture>
                 <source media="(max-width: 768px)" srcset="{{ url_for('static', filename='images/comics/' + comic.mobile_filename) }}">
@@ -29,6 +39,7 @@
                  alt="{{ comic.title if comic.title else '#' ~ comic.number }}"
                  title="{{ comic.alt_text }}">
             {% endif %}
+        {% endif %}
     </div>
 
     <div class="comic-navigation">