PowerBuilder’s Web Service prowess has increased significantly in recent releases from Appeon - in particular, PB2017 R2 and R3 release. These PowerBuilder releases have given us a new HTTP Client and RESTful Client capabilities that can utilize the newer JSON (JavaScript Object Notation) data format and the ever-popular XML (Extensible Markup Language) data format as well. When processing standard data type information in either the JSON or XML format, the ease of data exchange is very high. However, when trying to transfer binary data, the JSON and XML formats and the supporting HTTP transport layer for RESTful web services will not readily handle binary data.
To address this binary dilemma in the JSON and XML realm, today’s applications utilize the Base64 binary-to-text encoding mechanism to convert binary data into ASCII text sequences of the data. This allows the converted data to be injected into the JSON or XML schema and transmitted without upsetting the HTTP transport protocol. While it does increase the overall transmission data length when utilizing this encoding scheme, it is necessary in order to achieve the end goal of data exchange with these technologies.
In PB2017 R3, PowerBuilder will be updated to include new functions to both encode and decode binary data to and from the Base64 encoding scheme. The new PB built-in Base64Encode and Base64Decode commands can now perform the encoding in and out of the Base64 scheme using the standard PowerBuilder run-time engine support. For example, the PB Base64 PNG image used in this article would look like the following in a hexadecimal editor:
Figure 1- PowerBuilder Base64 Image in Hex
Using the new built-in Base64Encode method, the PNG image binary data is converted into a set of ASCII character sequences which can now be easily transmitted or even read by a simple text editor, as follows:
PowerBuilder’s prowess to be able to create Portable Document Format (PDF), has been supported for a long time in the product’s history. PDF documents have become the gold standard for delivering information, especially in the form of reports. PowerBuilder’s PDF generation capabilities are as follows (in historical order of their introduction):
External DLL – third party solutions that can be called via PB external method declarations in the early days of PB.XLSFO (Extensible Stylesheet Language Formatting Objects) - a Java-based solution included with the PB run-time and supported by the DataWindow, which was introduced in PB 7.PostScript Printer – third party printer solutions that do not require a PB interface but only require a PB app to print to an MS-Windows installed printer.GhostScript – an open source solution that PB can utilize via a specially installed printer definition named “Sybase DataWindow PS”, which was introduced in PB 9.NativePDF – a built-in PDF solution (i.e. doesn’t require separate licensing or installation of third-party solutions), which was introduced in PB 2017.All the above PDF generation mechanisms are still in place today (for backwards compatibility) in PB 2017. However, it is important to understand the advantages and disadvantages of these PDF generation mechanisms and use the appropriate one for your project, especially considering the enhancements made to the NativePDF option in the upcoming PB 2017 R3 release. In this blog, we’ll attempt to get a better perspective on these PDF options.
A variety of external PDF solutions exists for PowerBuilder and are commonly used in many existing projects. However, they often come with a significant extra price tag. They also come with the requirement to define external functions and maintain PowerScript code to support the external connectivity. Since these are developed and maintained by third party vendors, if you chose an unreliable vendor or the vendor ceases to continue the product then to move to a new vendor’s product usually will require a significant re-programming effort. On the plus side, if you choose a good third-party product, it produces a high-quality rendering and supports advanced PDF features.