Refactor card badge and multiselect template tags to properly implement and/or improve caching and context handling

- Updated `card_badge` and `card_multiselect` template tags to utilize `reverse_lazy` for URL resolution.
- Enhanced caching mechanisms in `card_badge.html` and `card_multiselect.html` to improve performance.
- Introduced a new template `_card_multiselect_options.html` for rendering multiselect options.
- Improved context management in `card_multiselect` to handle selected cards and dynamic placeholders.
- Added error handling for query hashing in `card_multiselect` to ensure robustness.
- Updated `trade_offer_tags` to optimize database queries using `select_related` for related objects.

cards/templatetags/card_badge.py

@@ -1,41 +1,46 @@
 from django import template
+from django.conf import settings
 from django.template.loader import render_to_string
 from django.utils.safestring import mark_safe
-from django.urls import reverse
+from django.urls import reverse_lazy
 
 register = template.Library()
 
-@register.inclusion_tag("templatetags/card_badge.html")
+@register.inclusion_tag("templatetags/card_badge.html", takes_context=True)
-def card_badge(card, quantity=None, expanded=False):
+def card_badge(context, card, quantity=None, expanded=False):
-    url = reverse('cards:card_detail', args=[card.pk])
+    """
-    return {
+    Renders a card badge.
+    """
+    url = reverse_lazy('cards:card_detail', args=[card.pk])
+    tag_context = {
         'quantity': quantity,
         'style': card.style,
         'name': card.name,
         'rarity': card.rarity_icon,
         'cardset': card.cardset,
         'expanded': expanded,
+        'cache_key': f'card_badge_{card.pk}_{quantity}_{expanded}',
         'url': url,
     }
+    context.update(tag_context)
+    return context
 
 @register.filter
 def card_badge_inline(card, quantity=None):
     """
-    Renders an inline card badge.
+    Renders an inline card badge by directly rendering the template.
     """
-    url = reverse('cards:card_detail', args=[card.pk])
+    url = reverse_lazy('cards:card_detail', args=[card.pk])
-    html = render_to_string("templatetags/card_badge.html", {
+    tag_context = {
         'quantity': quantity,
         'style': card.style,
         'name': card.name,
         'rarity': card.rarity_icon,
         'cardset': card.cardset,
         'expanded': True,
+        'cache_key': f'card_badge_{card.pk}_{quantity}_{True}',
+        'CACHE_TIMEOUT': settings.CACHE_TIMEOUT,
         'url': url,
-    })
+    }
+    html = render_to_string("templatetags/card_badge.html", tag_context)
     return mark_safe(html)
-
-@register.filter
-def addstr(arg1, arg2):
-    """concatenate arg1 & arg2"""
-    return str(arg1) + str(arg2)

cards/templatetags/card_multiselect.py

@@ -1,54 +1,72 @@
+import uuid
 from django import template
 from cards.models import Card
-
+from django.db.models.query import QuerySet
+import json
+import hashlib
+import logging
 register = template.Library()
 
-@register.inclusion_tag('templatetags/card_multiselect.html')
+@register.filter
-def card_multiselect(field_name, label, placeholder, cards=None, selected_values=None, cache_timeout=86400):
+def get_item(dictionary, key):
+    """Allows accessing dictionary items using a variable key in templates."""
+    return dictionary.get(key)
+
+@register.simple_tag
+def fetch_all_cards():
+    """Simple tag to fetch all Card objects."""
+    return Card.objects.order_by('pk').all()
+
+@register.inclusion_tag('templatetags/card_multiselect.html', takes_context=True)
+def card_multiselect(context, field_name, label, placeholder, cards=None, selected_values=None):
     """
-    Renders a multiselect field for choosing cards while supporting quantity data.
+    Prepares context for rendering a card multiselect input.
-    
+    Database querying and rendering are handled within the template's cache block.
-    Updated to allow `card_filter` to be either a dictionary (of lookup parameters) or a QuerySet.
-    This is useful when you want to limit available cards based on your new trades models (e.g. showing only
-    cards that appear in active trade offers).
-    
-    Parameters:
-      - field_name: The name attribute for the select tag.
-      - label: Label text to show above the selector.
-      - placeholder: Placeholder text to show in the select.
-      - selected_values: (Optional) A list of selected values; if a value includes a quantity it should be in the format "card_id:quantity".
-      - cache_timeout: (Optional) Cache timeout (in seconds) for the options block.
-      - cache_key: (Optional) Cache key.
     """
     if selected_values is None:
         selected_values = []
-    # Create a mapping {card_id: quantity}
+
     selected_cards = {}
     for val in selected_values:
         parts = str(val).split(':')
+        if len(parts) >= 1 and parts[0]:
             card_id = parts[0]
             quantity = parts[1] if len(parts) > 1 else 1
-        selected_cards[card_id] = quantity
+            selected_cards[str(card_id)] = quantity
 
-    if cards is None:
+    effective_field_name = field_name if field_name is not None else 'card_multiselect'
-       cards = Card.objects.all()
+    effective_label = label if label is not None else 'Card'
+    effective_placeholder = placeholder if placeholder is not None else 'Select Cards'
 
-    # Loop through available cards and attach pre‑selected quantity
+    selected_cards_key_part = json.dumps(selected_cards, sort_keys=True)
-    for card in cards:
+
-        pk_str = str(card.pk)
+    has_passed_cards = isinstance(cards, QuerySet)
-        if pk_str in selected_cards:
+
-            card.selected_quantity = selected_cards[pk_str]
+    if has_passed_cards:
-            card.selected = True
+        try:
+            query_string = str(cards.query)
+            passed_cards_identifier = hashlib.sha256(query_string.encode('utf-8')).hexdigest()
+        except Exception as e:
+            logging.warning(f"Could not generate query hash for card_multiselect. Error: {e}")
+            passed_cards_identifier = 'specific_qs_fallback_' + str(uuid.uuid4())
     else:
-            card.selected_quantity = 1
+        passed_cards_identifier = 'all_cards'
-            card.selected = False
 
-    return {
+    # Define the variables specific to this tag
-        'field_name': field_name,
+    tag_specific_context = {
-        'field_id': field_name,  # using the name as id for simplicity
+        'field_name': effective_field_name,
-        'label': label,
+        'field_id': effective_field_name,
-        'cards': cards,
+        'label': effective_label,
-        'placeholder': placeholder,
+        'placeholder': effective_placeholder,
-        'selected_values': list(selected_cards.keys()),
+        'passed_cards': cards if has_passed_cards else None,
-        'cache_timeout': cache_timeout
+        'has_passed_cards': has_passed_cards,
+        'selected_cards': selected_cards,
+        'selected_cards_key_part': selected_cards_key_part,
+        'passed_cards_identifier': passed_cards_identifier,
     }
+
+    # Update the original context with the tag-specific variables
+    # This preserves CACHE_TIMEOUT and other parent context variables
+    context.update(tag_specific_context)
+
+    return context # Return the MODIFIED original context

theme/templatetags/_card_multiselect_options.html

@@ -0,0 +1,30 @@
+{% load card_badge card_multiselect %}
+<option value="" disabled>{{ placeholder }}</option>
+{% for card in cards_to_render %}
+  {% with card_id_str=card.pk|stringformat:"s" %} {# Ensure card PK is string for lookup #}
+    {% if card_id_str in selected_cards %}
+        <option
+            value="{{ card.pk }}:{{ selected_cards|get_item:card_id_str }}"
+            data-card-id="{{ card.pk }}"
+            data-quantity="{{ selected_cards|get_item:card_id_str }}"
+            selected
+            data-html-content='<div class="m-2">{{ card|card_badge_inline:selected_cards|get_item:card_id_str }}</div>'
+            data-name="{{ card.name }}"
+            data-rarity="{{ card.rarity_icon }}"
+            data-cardset="{{ card.cardset }}">
+            {{ card.name }} {{ card.rarity_icon }} {{ card.cardset }}
+        </option>
+    {% else %}
+        <option
+            value="{{ card.pk }}:1"
+            data-card-id="{{ card.pk }}"
+            data-quantity="1"
+            data-html-content='<div class="m-2">{{ card|card_badge_inline:"" }}</div>'
+            data-name="{{ card.name }}"
+            data-rarity="{{ card.rarity_icon }}"
+            data-cardset="{{ card.cardset }}">
+            {{ card.name }} {{ card.rarity_icon }} {{ card.cardset }}
+        </option>
+    {% endif %}
+  {% endwith %}
+{% endfor %}

theme/templatetags/card_badge.html

@@ -1,3 +1,5 @@
+{% load cache %}
+{% cache CACHE_TIMEOUT card_badge cache_key %}
   <a href="{{ url }}" @click.stop>
     <div class="relative block">
       {% if not expanded %}
@@ -24,3 +26,4 @@
       {% endif %}
     </div>
   </a>
+{% endcache %}

theme/templatetags/card_multiselect.html

@@ -1,22 +1,16 @@
 {% load cache card_badge %}
+{% load cache card_multiselect %}
+
 <label for="{{ field_id }}" class="label">
   <span class="label-text">{{ label }}</span>
 </label>
 <select name="{{ field_name }}" id="{{ field_id }}" class="select select-bordered w-full card-multiselect" data-placeholder="{{ placeholder }}" multiple x-cloak>
-  {% cache cache_timeout card_multiselect selected_values|join:"," %}
+  {% cache CACHE_TIMEOUT card_multiselect field_name label placeholder passed_cards_identifier selected_cards_key_part %}
-    <option value="" disabled>{{ placeholder }}</option>
+    {% if has_passed_cards %}
-    {% for card in cards %}
+      {% include "templatetags/_card_multiselect_options.html" with cards_to_render=passed_cards selected_cards=selected_cards placeholder=placeholder %}
-      <option 
+    {% else %}
-        value="{{ card.pk }}"
+      {% fetch_all_cards as all_db_cards %}
-        data-card-id="{{ card.pk }}"
+      {% include "templatetags/_card_multiselect_options.html" with cards_to_render=all_db_cards selected_cards=selected_cards placeholder=placeholder %}
-        data-quantity="{{ card.selected_quantity }}"
+    {% endif %}
-        {% if card.selected %}selected{% endif %}
-        data-html-content='<div class="m-2">{{ card|card_badge_inline:"__QUANTITY__" }}</div>'
-        data-name="{{ card.name }}"
-        data-rarity="{{ card.rarity_icon }}"
-        data-cardset="{{ card.cardset }}">
-        {{ card.name }} {{ card.rarity_icon }} {{ card.cardset }}
-      </option>
-    {% endfor %}
   {% endcache %}
 </select>

theme/templatetags/trade_acceptance.html

@@ -1,5 +1,6 @@
 {% load gravatar card_badge %}
 
+{% cache CACHE_TIMEOUT trade_acceptance cache_key %}
   <div class="card card-border bg-base-100 shadow-lg max-w-90 mx-auto">
     <!-- Header -->
     <a href="{% url 'trade_acceptance_update' pk=acceptance.pk %}">
@@ -56,3 +57,4 @@
       </div>
     </a>
   </div> 
+{% endcache %}

theme/templatetags/trade_offer.html

@@ -1,6 +1,6 @@
 {% load gravatar card_badge cache %}
 
-{% cache 60 trade_offer offer_pk %}
+{% cache CACHE_TIMEOUT trade_offer cache_key %}
   <div x-data="{ flipped: {{flipped|lower}}, offerExpanded: {{flipped|yesno:'false,true'}}, acceptanceExpanded: {{flipped|lower}} }" x-ref="tradeOffer" class="transition-all duration-500 trade-offer-card">
     <div class="flip-container">
       <div class="flip-inner grid grid-cols-1 grid-rows-1 card bg-base-100 card-border shadow-lg w-90 transform transition-transform duration-500 ease-in-out{%if flipped %} rotate-y-180{% endif %}"

trades/apps.py

@@ -5,6 +5,5 @@ class TradesConfig(AppConfig):
     name = "trades"
 
     def ready(self):
-        # This import registers the signal handlers defined in trades/signals.py,
+        # Implicitly connect signal handlers decorated with @receiver.
-        # ensuring that denormalized field updates occur whenever related objects change.
         import trades.signals

trades/signals.py

@@ -1,7 +1,7 @@
 from django.db.models.signals import post_save, post_delete, pre_save
 from django.dispatch import receiver
 from django.db.models import F
-from trades.models import TradeOfferHaveCard, TradeOfferWantCard, TradeAcceptance
+from trades.models import TradeOfferHaveCard, TradeOfferWantCard, TradeAcceptance, TradeOffer
 from django.db import transaction
 from accounts.models import CustomUser
 from datetime import timedelta
@@ -12,6 +12,8 @@ from django.core.mail import send_mail
 from django.conf import settings
 from django.template.loader import render_to_string
 from django.contrib.sites.models import Site
+from django.core.cache import cache
+import logging
 
 POSITIVE_STATES = [
     TradeAcceptance.AcceptanceState.ACCEPTED,
@@ -260,3 +262,17 @@ def trade_acceptance_reputation_delete(sender, instance, **kwargs):
         CustomUser.objects.filter(pk=instance.trade_offer.initiated_by.user.pk).update(
             reputation_score=F("reputation_score") + 1
         )
+
+@receiver(post_save, sender=TradeOfferHaveCard)
+@receiver(post_delete, sender=TradeOfferHaveCard)
+@receiver(post_save, sender=TradeOfferWantCard)
+@receiver(post_delete, sender=TradeOfferWantCard)
+@receiver(post_save, sender=TradeAcceptance)
+@receiver(post_delete, sender=TradeAcceptance)
+def bubble_up_trade_offer_updates(sender, instance, **kwargs):
+    """
+    Bubble up updates to the TradeOffer model when TradeOfferHaveCard, TradeOfferWantCard,
+    or TradeAcceptance instances are created, updated, or deleted.
+    """
+    if instance.trade_offer:
+        instance.trade_offer.save(update_fields=['updated_at'])

trades/templatetags/trade_offer_tags.py

@@ -9,8 +9,10 @@ def render_trade_offer(context, offer):
     Renders a trade offer including detailed trade acceptance information.
     Freezes the through-model querysets to avoid extra DB hits.
     """
-    trade_offer_have_cards = list(offer.trade_offer_have_cards.all())
+    trade_offer_have_cards = list(offer.trade_offer_have_cards.select_related('card').all())
-    trade_offer_want_cards = list(offer.trade_offer_want_cards.all())
+    trade_offer_want_cards = list(offer.trade_offer_want_cards.select_related('card').all())
+    acceptances = list(offer.acceptances.select_related('accepted_by__user', 'requested_card', 'offered_card').all())
+
 
     have_cards_available = [
         card for card in trade_offer_have_cards
@@ -21,18 +23,14 @@ def render_trade_offer(context, offer):
         if card.quantity > card.qty_accepted
     ]
 
-    acceptances = list(offer.acceptances.all())
-
-    # Determine if the offer should show its back side (acceptances view) by default.
-    # If either side has no available cards, then flip the offer.
     if not have_cards_available or not want_cards_available:
         flipped = True
     else:
         flipped = False
 
-    return {
+    tag_context = {
         'offer_pk': offer.pk,
-        'flipped': flipped,  # new flag to control the default face
+        'flipped': flipped,
         'offer_hash': offer.hash,
         'rarity_icon': offer.rarity_icon,
         'initiated_by_email': offer.initiated_by.user.email,
@@ -43,19 +41,25 @@ def render_trade_offer(context, offer):
         'want_cards_available': want_cards_available,
         'num_cards_available': len(have_cards_available) + len(want_cards_available),
         'on_detail_page': context.get("request").path.endswith("trades/"+str(offer.pk)+"/"),
+        'cache_key': f'trade_offer_{offer.pk}_{offer.updated_at.timestamp()}_{flipped}',
     }
 
+    context.update(tag_context)
+    return context
+
 @register.inclusion_tag('templatetags/trade_acceptance.html', takes_context=True)
 def render_trade_acceptance(context, acceptance):
     """
     Renders a simple trade acceptance view with a single row and simplified header/footer.
     """
-
+    tag_context = {
-    return {
         "acceptance": acceptance,
-        "request": context.get("request"),
+        'cache_key': f'trade_acceptance_{acceptance.pk}_{acceptance.updated_at.timestamp()}',
     }
 
+    context.update(tag_context)
+    return context
+
 @register.filter
 def get_action_label(acceptance, state_value):
     """