Webimages

This library can be used to download webimages in parallel before establishing products to reduce renderingtime due to serial downloads. Images should be placed with frame::image( ... updateFlags=16)

Get started by initializing an WebImageBundle Object. Takes a list of urls (optional) and a URLMarker-Enum (optional). URLs can be added individually or existing ones overridden as well after initializing the Object.
To download the webimages, use download_queue. This saves the images to the filesystem and saves the url-paths to the corresponding Webimages in the "queue".
When placing the image into a frame, the url should be processed by the function get_webimage_url with parameter check_preloads = True.

If an asset referenced in the datafile is not a webimage but sent with the payload of the renderpdf-request to priint:cloud (as zip-file), the path of the file can be retrieved by using the function get_path_of_zip_payload.

Enum URLMarker

These Enums contain the keys for "nameflags" for webimages as described in the comet-docu. It is recommended to use some way of filename-shortening (for example "only hash" or "ellipsize end") to avoid runnung into problems with too long filepaths.

Enum	Value
NONE	""
ELLIPSIZE_START	"kEllipsizeStart"
ELLIPSIZE_MIDDLE	"kEllipsizeMiddle"
ELLIPSIZE_END	"kEllipsizeEnd"
NO_HASH_ELLIPSIZE_END	"kNoHashkEllipsizeEnd"
NO_HASH	"kNoHash"
ONLY_HASH	"kOnlyHash"

Functions

get_webimage_url(...)

(url, check_preloads = True, add_mediaproxy = True, nameflag = URLMarker.ONLY_HASH)

Retrieves the webimage-url of a given URL. If a file from that URL was preloaded using the WebImageBundle-class, an absolute path is retrieved from the cached URL / path-values. If no local path can be returned, the mediaproxy and specified nameflag are added to the URL.

Parameters:	url (str) The webimage-URL that should be processed by this function.
	check_preloads (bool) Whether or not to retrieve the local filepath of a preloaded file.
	add_mediaproxy (bool) Whether or not to append the url to the mediaproxy-url of priint:cloud.
	nameflag (URLMarker) The URLMarker, that should be appended to the url, to modify the filename-length. It is recommended to use a URLMarker to avoid problems due to too long filepaths. For the available _URLMarker_s check URLMarker-Enum.
Returns:	A url with added components or local filepath of preloaded file.
Return Type:	str

get_urlmarker(...)

(urlmarker_str)

Retrieves an Enum by its string-value from the URLMarker-Enum.

Parameters:	urlmarker_str (str) A string-value of a URLMarker-Enum.
Returns:	An Enum of URLMarker.
Return Type:	URLMarker

get_path_of_zip_payload(...)

(relative_path)

Retrieves a path of a file from a zip-payload sent with the renderpdf-request. The files of zip-payloads are stored in the priint:cloud-ticket's folder and can be accessed by giving a relative path for the structure in the zip-file.

Parameters:	relative_path (str) A relative path to a file in the structure of the zip-file sent as ticket-palyoad.
Returns:	The absolute path of the file in the ticket-folder.
Return Type:	str

Class WebImage

WebImage(...)

(url, nameflag = URLMarker.NONE, add_mediaproxy = True)

Creates an instance of WebImage.

Parameters:	url (str) The URL of a webimage.
	nameflag (URLMarker) The nameflag / URLMarker to add to the URL.
	add_mediaproxy (bool) Whether or not to use the priint:cloud-mediaproxy with the url.
Returns:	Instance of WebImage
Return Type:	WebImage

create_download_url()

Create a download-url of this WebImage using the url-, nameflag- and add_mediaproxy-properties.

Returns:	A URL with components as given at object initialization.
Return Type:	str

get_download_url()

Get the download-url of this WebImage. If not created yet, it will be created using the url-, nameflag- and add_mediaproxy-properties.

Returns:	A URL with components as given at object initialization.
Return Type:	str

Class WebImageBundle

WebImageBundle(...)

(urls = None, nameflag = URLMarker.NONE, add_mediaproxy = True, clear_cache = False)

Parameters:	urls (list[str]) A list of URLs for webimages.
	nameflag (URLMarker) A URLMarker that should be applied to all URLs to modify filename-length. Default is URLMarker.ONLY_HASH
	add_mediaproxy (bool) Whether or not to use the priint:cloud's mediaproxy for downloads.
	clear_cache (bool) Whether or not to remove all previously cached urls / paths.
Returns:	Instance of WebImageBundle.
Return Type:	WebImageBundle

add_to_queue(...)

(item, override_duplicates = True)

Adds a WebImage-object to the internal queue-property of the object. Can override or omit in case of duplicates.

Parameters:	item (WebImage) The WebImage-object to be added to the queue.
	override_duplicates (bool) Whether or not to override an existing WebImage with the same url in the queue. Can be used to change the nameflag- or mediaproxy-options of a WebImage that is already in the queue.
Returns:	Instance of WebImageBundle.
Return Type:	WebImageBundle

download_queue()

Download all queue-items by creating their-webimage-urls as inputs and using the function comet.file.downloadWebImages. Saves the filepaths from the function's results and saves the final item-list in the comet module's variable comet.my_webimages_vars["preload_cache"].

Returns:	Instance of WebImageBundle.
Return Type:	WebImageBundle

evaluate_downloads(...)

(download_results)

Adds the local filepaths of downloaded files to the WebImage-objects from the queue by matching URLs.

Parameters:	download_results (List[Tuple[str, str, int]]) The result returned by comet.file.downloadWebImages: A list of results containing [URL, Path to local result file, Error code]
Returns:	The updated queue-list.
Return Type:	list[WebImage]

get_cached_path(...)

(url)

Retrieves the cached file system path for a given URL from the preloaded cache.

Parameters:	url (str) The URL for which the cached path is requested
Returns:	The corresponding file system path if the URL exists in the cache; otherwise, None.
Return Type:	str|None

get_cached_results()

Returns the current dictionary of preloaded URL-to-path mappings from the comet module's variable: comet.my_webimages_vars["preload_cache"].

Returns:	A dictionary mapping URLs (str) to their respective local file system paths (str).
Return Type:	dict

cache_results()

Populates and stores a URL-to-path mapping in the shared module cache. Iterates through the current processing queue (self.queue) and builds a dictionary of image URLs and their corresponding file system paths. This mapping is then stored in comet.my_webimages_vars["preload_cache"] for future retrieval.

Returns:	None
Return Type:	None

clear_cache()

Removes all previously cached urls / paths from the variable of the comet-module: comet.my_webimages_vars["preload_cache"]

Returns:	None
Return Type:	None