def buildCacheKey(self, width, height):
"""
Build cache key for result image data.
This varies by width and height if we know them.
If we don't know, then we user agent string itself as a part of the key,
so that different mobiles don't get wrong image from the cache.
"""
# We know the user agent so we know the resulting width and height in this stage
if self.ua:
key = str(width) + "-" + str(height) + "-"
else:
key = get_user_agent_hash(self.request)
def add_param(key, value):
key += "-"
key += str(value)
return key
key = add_param(key, self.cache_key)
key = add_param(key, self.conserve_aspect_ration)
key = add_param(key, self.padding_width)
return key
def getImageDownloadURL(self, url, properties={}):
"""
Return download URL for image which is put through image resizer.
@param url: Source image URI, relative to context, or absolite URL
@param properties: Extra options needed to be given to the resizer, e.g. padding, max width, etc.
@return: String, URL where to resized image can be downloaded. This URL varies
by the user agent.
"""
self.init()
url = self.mapURL(url)
# Prepare arguments for the image resizer view
new_props = {"conserve_aspect_ration" : "true"}
new_props.update(properties)
new_props["url"] = url
if self.isUserAgentSpecific(url, new_props):
# Check if the result may vary by user agnt
new_props["user_agent_md5"] = get_user_agent_hash(self.request)
new_props = self.finalizeViewArguments(new_props)
return self.site.absolute_url() + "/" + VIEW_NAME + "?" + urllib.urlencode(new_props)
def getImageDownloadURL(self, url, properties={}):
"""
Return download URL for image which is put through image resizer.
@param url: Source image URI, relative to context, or absolite URL
@param properties: Extra options needed to be given to the
resizer, e.g. padding, max width, etc.
@return: String, URL where to resized image can be downloaded.
This URL varies by the user agent.
"""
self.init()
url = self.mapURL(url)
path = self.cache.makePathKey(url)
file = self.cache.get(path)
if file is None:
helper = ResizeViewHelper(self.context, self.request)
helper.init()
helper.parseParameters({'conserve_aspect_ration': True, 'url': url})
width, height = helper.resolveDimensions()
tool = getUtility(IImageInfoUtility)
logger.debug(
"Resizing image to mobile dimensions %d %d" % (
width, height)
)
data, format = tool.getURLResizedImage(url, width, height,
conserve_aspect_ration=True)
# Mercifully cache broken images from remote HTTP downloads
if data is None:
value = ""
else:
value = data.getvalue()
self.cache.set(path, value)
# Prepare arguments for the image resizer view
new_props = {"conserve_aspect_ration" : "true"}
new_props.update(properties)
new_props["key"] = path
if self.isUserAgentSpecific(url, new_props):
# Check if the result may vary by user agnt
new_props["user_agent_md5"] = get_user_agent_hash(self.request)
new_props = self.finalizeViewArguments(new_props)
return (self.site.absolute_url() + "/" + VIEW_NAME + "?" +
urllib.urlencode(new_props))
def getUserAgentBasedResizedImageURL(context, request, *args, **kwargs):
""" Get device-sensitive image URL.
Add device user agent hash to image URL so that caches won't mix different user agent images.
"""
context = aq_inner(context)
# Will raise ComponentLookUpError
name = "mobile_image_resizer"
view = getMultiAdapter((context, request), name=name)
view = view.__of__(context)
# Make user that each user agent gets its own logo version and not cached version for some other user agent
user_agent_md5 = get_user_agent_hash(request)
kwargs["user_agent_md5"] = user_agent_md5
return getResizedImageURL(*args, **kwargs)
