NAME XAO::ImageCache - Images caching by URLs stored in XAO::FS database SYNOPSIS use XAO::ImageCache; # Making new instance of Image Cache object my $image_Cache = XAO::ImageCache->new( list => $odb->fetch("/Products"), cache_path => "/var/httpd/shop/product/images/", cache_url => "/products/images/", source_url_key => "source_img", ) || die "Can't make Image cache!"; # Init new empty Cache $image_cache->init() || die "Can't init new cache!"; # Start images checking and downloading to cache $image_cache->check(); DESCRIPTION When we store images links on own database we have no real images on own site. Some time it may be a problem cause images may have no right dimension or may be deleted from source site. XAO::ImageCache made for cache locally images his URL stored in XAO Founsation Server. Also, images may be resized automaticaly. This module provide easy methods to scan XAO Foundation Server data lists, to extract images source URLs from data objects, to download images to local cache, to resize a local copy of the image to fit into given dimensions and to store the new local URL of the image back to the data object. METHODS new($%) The constructor returns a new "XAO::ImageCache" object. You can use it to make new images cache or check images of already existent cache. my $image_cache = XAO::ImageCache->new( cache_path => "cache", # set cache directory to './cache/' source_path => "cache/source", # set source directory to './cache/source/' local_path => "images/copy", # (optional) try to resolve local urls cache_url => "images/", # set cached images (relative) path to 'images/' list => $odb->fetch("/Products"), source_url_key => 'source_image_url', dest_url_key => 'dest_image_url', filename_key => 'product_id', min_width => 50, # Source image is ignored if smaller min_height => 50, size => { width => 320, height => 200, save_aspect_ratio => 1, }, thumbnails => { path => '/var/httpd/shop/product/images/tbn', url => '/products/images/tbn/' geometry => "25%", url_key => 'thumbnail_url', }, autocreate => 1, useragent => { agent => 'My Lovely Browser/v13.01', timeout => 30, }, force_download => 1, # to enforce re-downloads force_scale => 1, # to enforce re-scaling clear_on_error => 0, # don't clear DB properties even on permanent errors ) || die "Image cache creation failure!"; A number of configuration parameters can be passed to XAO::ImageCache to tune functionality. autocreate cache_path cache_url clear_on_error dest_url_key force_download force_scale list source_url_key size thumbnails useragent Follow to CONFIGURATION PARAMETERS section to see what each parameter does. If any required parameter is not present an error will be thrown. init($) Cache structure initialization. Executed automaticaly if "autocreate" parameter present. Create image cache directory if non existent and thumbnail cache directory if non existent and defined as initialization parameter. check($) Goes through given XAO FS data list, downloads images from source url to cache and puts cache url into destination url key and thumbnail url key (where applicable). XAO::ImageCache->download() will be executed for downloading each image. download($$) Downloads image into cache directory. If "thumbnails" contains "cache_path" parameter, thumbnail is either downloaded into thumbnail cache directory or created from downloaded image. Source image URL should be passed as parameter. Source thumbnail URL is an optional parameter: $img_cache->download($image_source_url, $thumbnail_source_url); Downloaded image is resized if "size" parameter present. Thumbnail is resized as specified by "thumbnails" "geometry" parameter. When "force_download" configuration parameter is not set to True value, image will be downloaded into cache only if image is not already cached or if cached image has a later modification date than source image. scale_large($$$) Scaling image to given size. scale_thumbnail($$$) Creates thumbnail image from given source image. remove_cache($) Removing the ENTIRE cache directory from disk. Be carefully to use this method!!! Cache structure will be removed from disk completely! Set "force_download" parameter to True value to download images to cache without any conditions. get_filename($) File name generation for cached images. Source image URL should be passed. Returned file name is an MD5 digest of the source URL converted to Base64 string with all non alpha numeric characters are converted to "_". Example. Location: http://localhost/icons/medbutton.jpeg provide file name: 4aFNA1utpmCNG2wEIF69mg.jpeg treat_filename($) Makes sure only file name friendly characters are present: all non alpha numeric characters are converted to "_". CONFIGURATION PARAMETERS The set of configuration parameters contain required and optional parameters. Required parameters should be defined. Execution will be stoped if required parameter not present. Optional parameters just configure aditional functionality and may not present. Required parameters cache_path - Path string where the cache should be placed. May be absolute or relative from current execution directory path. For example. Set it to "./cache" if you whant to place cache in "cache" subdirectory of your script working directory. cache_url - complet URL (or relative location) to cached images. Place here your URL reflection of cache directory in condition with your HTTP server configuration. For example. Set it to "http://my.host.com/images/" if your HTTP server configured for provide access to your cache directory by hostname "my.host.com" and location "images/". Cached images names will be added to image URL automaticaly. list - reference to "XAO::DO::FS::List" object containing the data objects with Image source URL Meaning, your data look like a XAO Foundation Server list of objects with references to images. This parameter should contain reference to to XAO::DO::FS::List object. This reference may be result of XAO::Objects->fetch() methode. XAO::ImageCache will process each record of this list. source_url_key - data key containing the URL of source image. Contain the name of key of data object containing the source image reference. Optional parameters dest_url_key - data key for storing URL of image in cache. Optional parameter cause image name in cache will be a MD5 Base64 digest of source image path where "=" character removed, "\" and "+" translated to "_" and "-" simultaniosely. To get cached image name size - Prefered image size may set as "geometry" equal to "geometry" parameter of Image::Magick module to pass it dirrectly to Image::Magick Scale function. Other way to set the image size is set a width and height keys to preffered values. If one of image dimension is not defined then corresponding parameter of original image will be used. This way, image will be resized with same aspect ratio (same proportions) to the original image if "save_aspect_ratio" parameter present. Image width and height will be resized exactly to given size if "save_aspect_ratio" parameter not present. Parameter "geometry" has higher priority and other parameters has no effects if "geometry" peresent. For example. # Size 320x200 as geometry settings %params = (size => {geometry => "320x200!"} ); # Size 320x200 as dimensions settings %params = (size => {width => 320, height => 200} ); # Fit size into 320x200 with saving image proportions %params = ( size => { width => 320, height => 200, save_aspect_ratio => 1, } ); autocreate - create or check cache content automaticaly. If non zero value present, cache directory will be created and images checking will be runned. Otherwithe you should run init() and check() methodes manualy. Existent cache directory will not be removed. You may do it manualy using remove_cache() methode. force_download - each image should be reloaded to cache and processed without dependance of source image modification time. Any conditions ignored. thumbnail - thumbnails creator configuration Some thubnails configuration parameters may be set for automatic thumbnails creation. This parameter should contain the reference to hash with thumbnails configuration parameters. Only "path" parameter is required. Other parameters are optional. path path where thumbnail images should be placed. url URL for access to thumbnails directory. Same way as "cache_url". url_key Data object key name where thumbnail URL should be stored. geometry Geometry string to set thumbnail images size in Image Magick geometry format. May be set as dimension ("320x200!") or as persent of actual size of cached image ("25%"). Default value is "50%" the half of actual image size. useragent - configuration parameters hash for LWP::UserAgent agent Default value "XAO-ImageCache/#.##" env_proxy Default value 1 keep_alive Default value 1 timeout Default value 30 For more information please follow to LWP::UserAgent SEE ALSO Specifics of List API can be found in XAO::DO::FS::List. For additional information please see XAO::DO::FS::Glue, XAO::DO::FS::Global, XAO::DO::FS::Glue::MySQL_DBI, Refer to Image::Magick documentation for additional information about setting of image scaling parameters. Refer to LWP::UserAgent documentation for additional information about user agent parameters. BUGS Please, inform me about found bugs. AUTHORS The XAO::ImageCache package maintained by Konstantin Safronov . Specification by Andrew Maltsew