Refactor thumbnails

inventory-app/inventory.py

@@ -1,6 +1,7 @@
 import boto3
 import pymongo
 from datetime import datetime
+from botocore.exceptions import ClientError
 from bson.objectid import ObjectId
 from flask import Blueprint, abort, g, make_response, redirect, render_template, request
 from jpegtran import JPEGImage
@@ -33,17 +34,23 @@ def view_inventory_view(item_id):
         can_audit = "k-space:janitors" in user["groups"]
         can_edit = check_edit_permission(item_id)
         is_using = item_user and item_user == user["username"]
-    bucket=get_bucket()
-    photo_url = bucket.generate_presigned_url(
-        ClientMethod='get_object',
-        Params={
-            'Bucket': const.BUCKET_NAME,
-            'Key': item_id
-        },
-        ExpiresIn=3600
-    )
+    photo_url = get_image_url(item_id)
     return render_template(template , **locals())
 
+def get_image_url(item_id):
+    bucket=get_bucket()
+    try:
+        return bucket.generate_presigned_url(
+            ClientMethod='get_object',
+            Params={
+                'Bucket': const.BUCKET_NAME,
+                'Key': item_id
+            },
+            ExpiresIn=3600
+        )
+    except ClientError:
+        return None
+
 def fetch_members_select():
     choices = [(None, None)]
     for username, user in g.users_lookup.items():
@@ -284,6 +291,10 @@ def upload_photo(item_id):
         return "File is not valid", 400
 
 
+@page_inventory.app_template_filter('thumbnail')
+def thumbnail_filter(item_id, dimension):
+    return get_scaled_photo(item_id, dimension)
+
 @page_inventory.route("/m/photo/<item_id>/<dimension>")
 def get_scaled_photo(item_id=None, dimension=0, retry=2):
     dimension = int(dimension) #why
@@ -296,21 +307,15 @@ def get_scaled_photo(item_id=None, dimension=0, retry=2):
         return abort(404)
     if item.get("thumbs", {}).get(str(dimension)):
         thumb = item["thumbs"][str(dimension)]
-        img = get_item(thumb["name"])
-        if not img:
+        img_url = get_image_url(thumb["name"])
+        if not img_url:
             delete_thumbs(item)
             return get_scaled_photo(item_id, dimension, retry - 1)
-        img = JPEGImage(blob=img)
     else:
         make_thumb(item, dimension)
         return get_scaled_photo(item_id, dimension, retry - 1)
 
-    response = make_response(img.as_blob())
-    response.headers.set('Content-Type', 'image/jpeg')
-    response.cache_control.public = True
-    response.cache_control.immutable = True
-    response.cache_control.max_age = 31536000
-    return response
+    return img_url
 
 def get_item(key):
     try:

inventory-app/templates/inventory_grid.html

@@ -8,7 +8,7 @@
         <div class="col s4">
             <div class="card medium">
                 <div class="card-image">
-                    <img src="{% if item.has_photo %}/m/photo/{{ item._id }}/576{% else %}/static/No_image_available.svg{% endif %}" alt="no photo" loading="lazy">
+                  <img src="{% if item.has_photo %}{{ item._id | thumbnail(576)}}{% else %}/static/No_image_available.svg{% endif %}" alt="no photo" loading="lazy">
                 </div>
                 <div class="card-content">
                   <span class="line-clamp card-title activator grey-text text-darken-4">{{ item.name }}</span>