Proper handling for non existing covers in calibre database

cps/templates/detail.html

@@ -4,8 +4,10 @@
   <div class="row">
     <div class="col-sm-3 col-lg-3 col-xs-12">
       <div class="cover">
-        {% if entry.has_cover is defined %}
+        {% if entry.has_cover %}
           <img src="{{ url_for('get_cover', cover_path=entry.path.replace('\\','/')) }}" />
+        {% else %}
+          <img src="{{ url_for('static', filename='generic_cover.jpg') }}" />
         {% endif %}
       </div>
     </div>

cps/templates/edit_book.html

@@ -3,8 +3,10 @@
 {% if book %}
 <div class="col-sm-3 col-lg-3 col-xs-12">
   <div class="cover">
-    {% if book.has_cover is defined %}
+    {% if book.has_cover %}
       <img src="{{ url_for('get_cover', cover_path=book.path) }}" />
+    {% else %}
+      <img src="{{ url_for('static', filename='generic_cover.jpg') }}" />
     {% endif %}
   </div>
 </div>

cps/templates/index.html

@@ -8,11 +8,13 @@
     {% for entry in random %}
     <div class="col-sm-3 col-lg-2 col-xs-6 book">
       <div class="cover">
-        {% if entry.has_cover is defined %}
           <a href="{{ url_for('show_book', id=entry.id) }}">
-            <img src="{{ url_for('get_cover', cover_path=entry.path.replace('\\','/')) }}" />
+            {% if entry.has_cover %}
+              <img src="{{ url_for('get_cover', cover_path=entry.path.replace('\\','/')) }}" />
+            {% else %}
+              <img src="{{ url_for('static', filename='generic_cover.jpg') }}" />
+            {% endif %}
           </a>
-        {% endif %}
       </div>
       <div class="meta">
         <p class="title">{{entry.title|shortentitle}}</p>
@@ -41,11 +43,13 @@
     {% for entry in entries %}
     <div class="col-sm-3 col-lg-2 col-xs-6 book">
       <div class="cover">
-        {% if entry.has_cover is defined %}
           <a href="{{ url_for('show_book', id=entry.id) }}">
-            <img src="{{ url_for('get_cover', cover_path=entry.path.replace('\\','/')) }}" />
+            {% if entry.has_cover %}
+              <img src="{{ url_for('get_cover', cover_path=entry.path.replace('\\','/')) }}" />
+            {% else %}
+              <img src="{{ url_for('static', filename='generic_cover.jpg') }}" />
+            {% endif %}
           </a>
-        {% endif %}
       </div>
       <div class="meta">
         <p class="title">{{entry.title|shortentitle}}</p>