Show/hide toggle for long book descriptions

bookwyrm/templates/snippets/book_description.html

@@ -1,2 +1,20 @@
-<blockquote class="content">{% if book.description %}{{ book.description }}{% elif book.parent_work.description %}{{ book.parent_work.description }}{% endif %}</blockquote>
-
+{% load fr_display %}
+{% with book|book_description as full %}
+    {% with full|text_overflow as trimmed %}
+    {% if trimmed != full %}
+    <div>
+        <input type="radio" name="show-hide-{{ book.id }}" id="show-{{ book.id }}" class="toggle-control" checked>
+        <blockquote class="content toggle-content hidden">{{ trimmed }}
+        <label class="button is-small" for="hide-{{ book.id }}">show more</label></blockquote>
+    </div>
+    <div>
+        <input type="radio" name="show-hide-{{ book.id }}" id="hide-{{ book.id }}" class="toggle-control">
+        <blockquote class="content toggle-content hidden">{{ full }}
+        <label class="button is-small" for="show-{{ book.id }}">show less</label></blockquote>
+    </div>
+    {% else %}
+    <blockquote class="content">{{ full }}
+    </blockquote>
+    {% endif %}
+    {% endwith %}
+{% endwith %}

bookwyrm/templatetags/fr_display.py

@@ -106,6 +106,25 @@ def get_edition_info(book):
     return ', '.join(i for i in items if i)
 
 
+@register.filter(name='book_description')
+def get_book_description(book):
+    ''' use the work's text if the book doesn't have it '''
+    return book.description or book.parent_work.description
+
+
+@register.filter(name='text_overflow')
+def text_overflow(text):
+    ''' dont' let book descriptions run for ages '''
+    char_max = 500
+    if len(text) < char_max:
+        return text
+
+    trimmed = text[:char_max]
+    # go back to the last space
+    trimmed = ' '.join(trimmed.split(' ')[:-1])
+    return trimmed + '...'
+
+
 @register.simple_tag(takes_context=True)
 def shelve_button_identifier(context, book):
     ''' check what shelf a user has a book on, if any '''