Add simple tag to provide fallback if original image doesn't exist

This commit is contained in:
Joachim 2021-08-03 17:45:52 +02:00
parent 2370f60436
commit ce4553b367
2 changed files with 73 additions and 24 deletions

View file

@ -3,6 +3,7 @@
{% load i18n %}
{% load static %}
{% load imagekit %}
{% load utilities %}
{% if book.cover %}
<picture class="cover-container {{ cover_class }}">
@ -21,93 +22,130 @@
<source
media="(max-width: 768px)"
type="image/webp"
srcset="{{ book.cover_bw_book_xsmall_webp.url }}"
srcset="{% get_book_cover_thumbnail book=book size='xsmall' ext='webp' %}"
/>
<source
media="(max-width: 768px)"
type="image/jpg"
srcset="{{ book.cover_bw_book_xsmall_jpg.url }}"
srcset="{% get_book_cover_thumbnail book=book size='xsmall' ext='jpg' %}"
/>
{% elif size_mobile == 'small' %}
<source
media="(max-width: 768px)"
type="image/webp"
srcset="{{ book.cover_bw_book_small_webp.url }}"
srcset="{% get_book_cover_thumbnail book=book size='small' ext='webp' %}"
/>
<source
media="(max-width: 768px)"
type="image/jpg"
srcset="{{ book.cover_bw_book_small_jpg.url }}"
srcset="{% get_book_cover_thumbnail book=book size='small' ext='jpg' %}"
/>
{% elif size_mobile == 'medium' %}
<source
media="(max-width: 768px)"
type="image/webp"
srcset="{{ book.cover_bw_book_medium_webp.url }}"
srcset="{% get_book_cover_thumbnail book=book size='medium' ext='webp' %}"
/>
<source
media="(max-width: 768px)"
type="image/jpg"
srcset="{{ book.cover_bw_book_medium_jpg.url }}"
srcset="{% get_book_cover_thumbnail book=book size='medium' ext='jpg' %}"
/>
{% elif size_mobile == 'large' %}
<source
media="(max-width: 768px)"
type="image/webp"
srcset="{{ book.cover_bw_book_large_webp.url }}"
srcset="{% get_book_cover_thumbnail book=book size='large' ext='webp' %}"
/>
<source
media="(max-width: 768px)"
type="image/jpg"
srcset="{{ book.cover_bw_book_large_jpg.url }}"
srcset="{% get_book_cover_thumbnail book=book size='large' ext='jpg' %}"
/>
{% elif size_mobile == 'xlarge' %}
<source
media="(max-width: 768px)"
type="image/webp"
srcset="{{ book.cover_bw_book_xlarge_webp.url }}"
srcset="{% get_book_cover_thumbnail book=book size='xlarge' ext='webp' %}"
/>
<source
media="(max-width: 768px)"
type="image/jpg"
srcset="{{ book.cover_bw_book_xlarge_jpg.url }}"
srcset="{% get_book_cover_thumbnail book=book size='xlarge' ext='jpg' %}"
/>
{% elif size_mobile == 'xxlarge' %}
<source
media="(max-width: 768px)"
type="image/webp"
srcset="{{ book.cover_bw_book_xxlarge_webp.url }}"
srcset="{% get_book_cover_thumbnail book=book size='xxlarge' ext='webp' %}"
/>
<source
media="(max-width: 768px)"
type="image/jpg"
srcset="{{ book.cover_bw_book_xxlarge_jpg.url }}"
srcset="{% get_book_cover_thumbnail book=book size='xxlarge' ext='jpg' %}"
/>
{% endif %}
{% if size == 'xsmall' %}
<source type="image/webp" srcset="{{ book.cover_bw_book_xsmall_webp.url }}"/>
<source type="image/jpg" srcset="{{ book.cover_bw_book_xsmall_jpg.url }}"/>
<source
type="image/webp"
srcset="{% get_book_cover_thumbnail book=book size='xsmall' ext='webp' %}"
/>
<source
type="image/jpg"
srcset="{% get_book_cover_thumbnail book=book size='xsmall' ext='jpg' %}"
/>
{% elif size == 'small' %}
<source type="image/webp" srcset="{{ book.cover_bw_book_small_webp.url }}"/>
<source type="image/jpg" srcset="{{ book.cover_bw_book_small_jpg.url }}"/>
<source
type="image/webp"
srcset="{% get_book_cover_thumbnail book=book size='small' ext='webp' %}"
/>
<source
type="image/jpg"
srcset="{% get_book_cover_thumbnail book=book size='small' ext='jpg' %}"
/>
{% elif size == 'medium' %}
<source type="image/webp" srcset="{{ book.cover_bw_book_medium_webp.url }}"/>
<source type="image/jpg" srcset="{{ book.cover_bw_book_medium_jpg.url }}"/>
<source
type="image/webp"
srcset="{% get_book_cover_thumbnail book=book size='medium' ext='webp' %}"
/>
<source
type="image/jpg"
srcset="{% get_book_cover_thumbnail book=book size='medium' ext='jpg' %}"
/>
{% elif size == 'large' %}
<source type="image/webp" srcset="{{ book.cover_bw_book_large_webp.url }}"/>
<source type="image/jpg" srcset="{{ book.cover_bw_book_large_jpg.url }}"/>
<source
type="image/webp"
srcset="{% get_book_cover_thumbnail book=book size='large' ext='webp' %}"
/>
<source
type="image/jpg"
srcset="{% get_book_cover_thumbnail book=book size='large' ext='jpg' %}"
/>
{% elif size == 'xlarge' %}
<source type="image/webp" srcset="{{ book.cover_bw_book_xlarge_webp.url }}"/>
<source type="image/jpg" srcset="{{ book.cover_bw_book_xlarge_jpg.url }}"/>
<source
type="image/webp"
srcset="{% get_book_cover_thumbnail book=book size='xlarge' ext='webp' %}"
/>
<source
type="image/jpg"
srcset="{% get_book_cover_thumbnail book=book size='xlarge' ext='jpg' %}"
/>
{% elif size == 'xxlarge' %}
<source type="image/webp" srcset="{{ book.cover_bw_book_xxlarge_webp.url }}"/>
<source type="image/jpg" srcset="{{ book.cover_bw_book_xxlarge_jpg.url }}"/>
<source
type="image/webp"
srcset="{% get_book_cover_thumbnail book=book size='xxlarge' ext='webp' %}"
/>
<source
type="image/jpg"
srcset="{% get_book_cover_thumbnail book=book size='xxlarge' ext='jpg' %}"
/>
{% endif %}
{% endif %}
<img
alt="{{ book.alt_text|default:'' }}"
class="book-cover"
itemprop="thumbnailUrl"
src="{% if img_path is None %}{% get_media_prefix %}{% else %}{{ img_path }}{% endif %}{{ book.cover }}"

View file

@ -3,6 +3,7 @@ import os
from uuid import uuid4
from django import template
from django.utils.translation import gettext_lazy as _
from django.templatetags.static import static
register = template.Library()
@ -50,3 +51,13 @@ def truncatepath(value, arg):
except ValueError: # invalid literal for int()
return path_list[-1] # Fail silently.
return "%s/…%s" % (path_list[0], path_list[-1][-length:])
@register.simple_tag(takes_context=False)
def get_book_cover_thumbnail(book, size, ext):
"""Returns a book thumbnail at the specified size and extension, with fallback if needed"""
try:
cover_thumbnail = getattr(book, "cover_bw_book_%s_%s" % (size, ext))
return cover_thumbnail.url
except OSError:
return static("images/no_cover.jpg")