Michael R Sweet, the author of the CUPS printing system, introduced the release of PAPPL 1.3, a framework for developing printing applications based on the IPP Everywhere protocol, which is recommended for use instead of traditional printer drivers. The framework's code is written in C and is distributed under the Apache 2.0 license with an exception allowing linking to code under GPLv2 and LGPLv2 licenses.
The PAPPL framework was originally developed to support the LPrint printing system and Gutenprint drivers, but can be used to implement support for any printers and drivers when printing on desktop, server, and embedded systems. PAPPL is expected to help accelerate the adoption of IPP Everywhere technology instead of classic drivers and simplify support for other IPP-based applications, such as AirPrint and Mopria.
PAPPL includes a built-in implementation of the IPP Everywhere protocol, providing means to access printers locally or over a network and handle print requests. IPP Everywhere operates in a driverless mode and, unlike PPD drivers, does not require static configuration files to be created. It supports interaction with printers both directly via local USB printer connections and over the network using AppSocket and JetDirect protocols. Data can be sent to the printer in JPEG, PNG, PWG Raster, Apple Raster, and raw formats.
PAPPL can be built for POSIX-compatible operating systems, including Linux, macOS, QNX, and VxWorks. Dependencies include Avahi (for mDNS/DNS-SD support), CUPS, GNU TLS, JPEGLIB, LIBPNG, LIBPAM (for authentication), and ZLIB. Based on PAPPL, the OpenPrinting project develops a universal PostScript Printer Application that can work with both modern IPP-compatible printers (which use PAPPL) that support PostScript and Ghostscript, as well as older printers that have PPD drivers (using cups-filters and libppd).
Among the changes in the new version:
- The ability to hold and resume print jobs has been added.
- Debug logging for device management operations has been added.
- Support for scaling PNG images with built-in resolution information has been added.
- The capability to output a localized banner at the top of web pages with information about the printer and system has been provided.
- An API has been added for managing the execution of periodically scheduled tasks.
- Network configuration through callback calls has been implemented.
- An API has been added to limit the maximum size of JPEG and PNG images.
- Support for building with Clang/GCC in ThreadSanitizer mode (-enable-tsanitizer) has been added.
- A button to show the password has been added to the Wi-Fi password input field.
Source: opennet.ru
