diff core/images/upload.py @ 971:4f265f61874b

Hotlink image form is functioning. The user can now submit a URL via a form and the URL will be downloaded and uploaded to a S3 bucket if it is an image. Tests to follow.
author Brian Neal <bgneal@gmail.com>
date Tue, 22 Sep 2015 20:23:50 -0500 (2015-09-23)
parents core/image_uploader.py@51a2051588f5
children 7fc6c42b2f5b
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line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/core/images/upload.py	Tue Sep 22 20:23:50 2015 -0500
@@ -0,0 +1,94 @@
+"""This module contains a function to upload an image file to a S3Bucket.
+
+The image can be resized and a thumbnail can be generated and uploaded as well.
+
+"""
+from base64 import b64encode
+import logging
+from io import BytesIO
+import os.path
+import uuid
+
+from PIL import Image
+
+from .utils import orient_image
+
+
+logger = logging.getLogger(__name__)
+
+
+def make_key():
+    """Generate a random key suitable for a filename"""
+    return b64encode(uuid.uuid4().bytes, '-_').rstrip('=')
+
+
+def upload(filename, bucket, metadata=None, new_size=None, thumb_size=None):
+    """Upload an image file to a given S3Bucket.
+
+    The image can optionally be resized and a thumbnail can be generated and
+    uploaded as well.
+
+    Parameters:
+        filename - The path to the file to process. The filename should have an
+                   extension, and this is used for the uploaded image & thumbnail
+                   names.
+        bucket - A core.s3.S3Bucket instance to upload to.
+        metadata - If not None, must be a dictionary of metadata to apply to the
+                   uploaded file and thumbnail.
+        new_size - If not None, the image will be resized to the dimensions
+                   specified by new_size, which must be a (width, height) tuple.
+        thumb_size - If not None, a thumbnail image will be created with the
+                     dimensions specified by thumb_size, which must be a (width,
+                     height) tuple. The thumbnail will use the same metadata, if
+                     present, as the image. The thumbnail filename will be the
+                     same basename as the image with a 't' appended. The
+                     extension will be the same as the original image.
+
+    A tuple is returned: (image_url, thumb_url) where thumb_url will be None if
+    a thumbnail was not requested.
+    """
+
+    logger.info('Processing image file: %s', filename)
+
+    unique_key = make_key()
+    ext = os.path.splitext(filename)[1]
+
+    # Re-orient if necessary
+    image = Image.open(filename)
+    changed, image = orient_image(image)
+    if changed:
+        image.save(filename)
+
+    # Resize image if necessary
+    if new_size:
+        image = Image.open(filename)
+        if image.size > new_size:
+            logger.debug('Resizing from {} to {}'.format(image.size, new_size))
+            image.thumbnail(new_size, Image.ANTIALIAS)
+            image.save(filename)
+
+    # Create thumbnail if necessary
+    thumb = None
+    if thumb_size:
+        logger.debug('Creating thumbnail {}'.format(thumb_size))
+        image = Image.open(filename)
+        image.thumbnail(thumb_size, Image.ANTIALIAS)
+        thumb = BytesIO()
+        image.save(thumb, format=image.format)
+
+    # Upload images to S3
+    file_key = unique_key + ext
+    logging.debug('Uploading image')
+    image_url = bucket.upload_from_filename(file_key, filename, metadata)
+
+    thumb_url = None
+    if thumb:
+        logging.debug('Uploading thumbnail')
+        thumb_key = '{}t{}'.format(unique_key, ext)
+        thumb_url = bucket.upload_from_string(thumb_key,
+                                              thumb.getvalue(),
+                                              metadata)
+
+    logger.info('Completed processing image file: %s', filename)
+
+    return (image_url, thumb_url)