Some time ago, we posted an overview blog article on Adobe Content Server Permissions. As one of the three follow-up posts, this blog will cover what happens when you apply certain combinations of permissions to a book and try to do certain things with that book. This post in particular is the second in the series and will cover printing permissions. It is not dependent upon the previous post covering reading or the next post covering copying. However, if you are new to ACS permissions, it may help to read our permissions overview blog first.
We’ll start with the glossary to define some terms, followed by a few use cases. Afterwards we’ll explain some of the caveats and best practices for using reading permissions.
Before getting into things, it might be helpful to cover some basic terminology. Some of these may be obvious, but it’s worth listing them out to clear up any ambiguity between similar terms. (This glossary is the same in the other parallel blog posts, so skip it if you’ve read those.)
ACSM File – the download token generated when the user clicks the GB Link at the store.
Fulfill – to open an ACSM file and have the reader application communicate with the ACS server to download a book.
Open – to “double-click” an ACSM file or to perform a similar device-specific operation on the file, which does not necessarily imply a complete fulfillment; it is possible that opening an ACSM file will result in fulfillment errors in which case a fulfillment may not occur.
Side-load – to copy a book from a desktop reader application (like Adobe Digital Editions) to a tethered device connected via a USB port. Or, in more general terms, copy a fulfilled book from one device to another.
Re-download – to download an ACSM file using a new link; the new link will use the same resource ID and transaction ID (and thus have all the same restrictions) as the original download link, but will count as a “fresh” link as far as link expiration is concerned.
Below are the results of applying certain permissions to a book, then attempting to fulfill and perform actions on the book. For these tests, unless otherwise specified, the books were fulfilled in ADE first on one desktop computer, then an attempt was made to fulfill them on a second computer. Under unrestricted conditions, the book would open fine on both devices.
Print 1 page, any number of devices, no expiration:
• Can print a single page as expected. Can’t print more than one copy of the same page.
• The page gets decremented as soon as it’s sent to the printer. If printing is interrupted, the page will still remain decremented. However, if ADE is closed before the page is printed, the page will usually not print and will not cause a decrement. In some cases, however, the page may be printed but not decremented.
• Closing ADE after the printer has actually started printing will result in the proper number of pages being decremented.
• The second device will always have 0 pages available. This is the case whether the first device has actually printed pages or not, or whether the book has been side-loaded or re-downloaded. Since the page counts are stored locally, ACS must assume that the first device used up (or will use up) the allowed pages. Otherwise, it would be very easy for a customer to print more pages than you want them to simply by downloading to multiple devices.
• If the book is downloaded twice on the same device, some reader applications will display two instances of the book separately (ADE is one of these). In that case, both instances of the book will initially display 1 page. However, when one page is printed from either instance, both instances will display 0 pages available. The two instances are essentially the same book but just happen to be displayed twice.
Print 5 pages, any number of devices, no expiration:
• On the first device printing works as expected and works similarly to a single page. Printing multiple copies of the same page results in the allowed pages being decremented for each copy.
• If ADE is closed before all pages can be sent to the printer, only the sent pages will be decremented. Similarly to printing a single page, it’s possible that not all pages will be decremented. In this case, there will only ever be a single page discrepancy between printed pages and decremented pages. At no time will all 5 pages print with 0 pages decremented.
• Similar to a single page, a second device will always start at 0 pages allowed.
Print 5 pages, accrue 1 page per minute, 5 pages max (any devices, no expiration):
• First 5 print operations on first device behave as above.
• When the book is opened on the second device, it will still start with 0 pages available, regardless of how many pages were printed on the first device. However, it will accrue 1 page per minute up to 5 available pages maximum. Afterward, it will behave as normal.
• If the book is fulfilled twice on the same device, if the app displays the book as two separate instances, it will behave similarly to the case where only one page was available. The two instances will behave as if they’re a single book, with pages decrementing and accruing in unison.
Notes on Printing Permissions
The same notes that apply to reading also apply to printing. Expiration times and allowed pages can’t be reset by re-downloading the book.
Aside from that, the most important thing to remember is that page counts are stored locally and, if accrual isn’t set, will only be available on the first device to which the book is downloaded.
Additionally, it should be noted that books will re-accrue pages after they have been used up. This results in the user being able to print a single page per accrual period indefinitely, or at least until the expiration of the print permissions. The “maximum” number only applies to how many pages can be “saved up”. If you set accrual, you will not be able to set a limit on how many pages can ultimately be printed, but only how quickly they can be printed.
Finally, ADE (the released version as of this posting) has a little quirk in one corner case of how it displays allowed pages. If you happen to have two copies of the same book — the exact same book, with the same resource ID, downloaded with the same transaction ID — then the number of allowed pages displayed between them will be cumulative. However, printing pages from one of these books will decrement the counter on both books. In reality, the user will not get extra printable pages, though it may look like it at first.
That concludes our look at the more detailed side of printing permissions. The final blog in this series will follow this same format and cover specific use cases and caveats for the copying permission set.