Add type checks for demo ID and ensure string conversion in template data attributes

Author: ianlintner

flask_app/app.py

@@ -249,7 +249,9 @@ def get_categories() -> dict[str, list[dict]]:
 @app.context_processor
 def utility_processor():
     def get_card_type(category, demo):
-        if category == 'visualizations' or demo['id'].startswith('viz.'):
+        # Add a check for the existence of 'id' and its type
+        demo_id = demo.get('id')
+        if category == 'visualizations' or (isinstance(demo_id, str) and demo_id.startswith('viz.')):
             return 'visualization-card'
         if 'leetcode' in category:
             return 'leetcode-card'

flask_app/templates/index.html

@@ -85,7 +85,7 @@ <h3>No demos discovered</h3>
                        data-category="{{ category }}" 
                        data-id="{{ d.id }}"
                        data-status="{{ get_demo_status(d) }}"
-                       data-search-text="{{ (d.title + ' ' + category + ' ' + d.id)|lower }}">
+                       data-search-text="{{ (d.title + ' ' + category + ' ' + d.id|string)|lower }}">
 
                 <!-- Card Header -->
                 <header class="card-header">
@@ -136,7 +136,7 @@ <h3 class="card-title">{{ d.title }}</h3>
 
                 <!-- Card Actions -->
                 <footer class="card-actions">
-                  {% if category == 'visualizations' or d.id.startswith('viz.') %}
+                  {% if category == 'visualizations' or (d.id|string).startswith('viz.') %}
                     {% if d.id == 'viz.sorting' %}
                       <a class="btn-primary" href="{{ url_for('viz_sorting') }}">Launch</a>
                     {% elif d.id == 'viz.graph' %}