Example using SimpleDB and the logging server

comment.html

<p>Submitted an automated comment to that image.
Go <a href="http://imaj.lddi.org/view?imagekey=$key">view it</a>.</p>

<p><a href="/simpldb">Return</a></p>

index.html

<p>The most recent image has imagekey $key. You can view it 
<a href="http://imaj.lddi.org/view?imagekey=$key">here</a>.</p>

<p><a href="/simpledb/comment">Submit a comment for this image</a></p>

simpledb.py

import uuid
import time
import boto
import funcs
import urllib
import urllib2
from Cheetah.Template import Template

AWSKey = "{redacted}"
AWSSecret = "{redacted}"
imageDomain = "picture"
commentDomain = "comment"

#################################################
# SimpleDB: Image domain
#################################################
def index(req):
    # Get the imagekey of the most recently submitted image
    image = _getMostRecentImage()
    imagekey = image.name

    # Return the response in a template
    t = Template(file='/var/www/examples/index.html')
    t.key = imagekey
    req.content_type = "text/html"
    return t.__str__()

def _getImageDomain():
    sdb = boto.connect_sdb(AWSKey, AWSSecret)
    domain = sdb.lookup(imageDomain)
    return domain

def _getMostRecentImage():
    domain = _getImageDomain()
    # Query for all approved images with any submit date (magic number), sorted by submit date
    query = "['submitdate' <= '2900'] intersection ['status' = 'approved'] sort 'submitdate' desc"
    # Get one row
    numRows = 1
    # Run the query
    result = domain.query(query, numRows)
    # Result is a generator; get 
    recentImages = [i for i in result]

    return recentImages[0]


#################################################
# SimpleDB: Comment domain
#################################################
def comment(req):
    image = _getMostRecentImage()
    imagekey = image.name

    # Generate a UUID for this comment
    commentkey = uuid.uuid1()

    # Create a new item in the comment domain
    domain = _getCommentDomain()
    c = domain.new_item(commentkey)
    c['submituser'] = 'ExampleServer'
    c['imagekey'] = imagekey
    c['comment'] = 'This is an automated comment from an example server'
    c['submitdate'] = time.strftime("%Y-%m-%dT%H:%M:%S", time.gmtime())
    c.save()
    
    # Put the comment in the approval queue (implementation not important for Lab 3)
    funcs.addCommentToQueue(commentkey, c)

    # Return the response in a template
    t = Template(file='/var/www/examples/comment.html')
    t.key = imagekey
    req.content_type = "text/html"
    req.write(t.__str__())

def _getCommentDomain():
    sdb = boto.connect_sdb(AWSKey, AWSSecret)
    domain = sdb.lookup(commentDomain)
    return domain


#################################################
# Logging
#################################################
def log(req):
    return _postProcessingMessage()

def _postProcessingMessage():
    params = urllib.urlencode({'student': 'ExampleServer', \
        'type': 'INFO', \
        'system': 'appserver', \
        'message': 'This is a test logging message sent for example purposes'})
    return urllib2.urlopen('{redacted}', params).read()

The AWS keys and the location of the logging server endpoint were redacted.