Using dynamic libraries
You can store the objects used in your PowerBuilder application
in more than one library and, when you run the application, dynamically
load any objects that are not contained in the application’s
executable file. This allows you to break the application into smaller
units that are easier to manage and makes the executable file smaller.
You do this by using dynamic libraries. If you compile using Pcode,
PowerBuilder builds PowerBuilder dynamic libraries (PBD files).
If you use machine code, PowerBuilder builds Dynamic Link Libraries (DLL
files).
When you distribute your application to users, you distribute
the executable, the dynamic libraries, and PowerBuilder runtime
DLLs. For more information about deployment and a list of PowerBuilder
runtime DLLs, see Application Techniques.
Dynamic library names
PowerBuilder dynamic libraries are given the name of the PBL with the extension .pbd.
For example, the Pcode library built from test.pbl is
named test.pbd.
Machine-code dynamic libraries are given the extension .dll.
For example, the machine-code library built from test.pbl is
named test.dll.
Reducing the size of dynamic libraries
When PowerBuilder builds a dynamic library, it copies the
compiled versions of all objects from the source
library (PBL file) into the
dynamic library.
The easiest way to specify source libraries is simply to use
your standard PowerBuilder libraries as source libraries. However,
using this technique can make your dynamic libraries larger than
they need to be, because they include all objects from the source
library, not just the ones used in your application. You can create
a PowerBuilder library that contains only the objects that you want
in a dynamic library.
To create a source library to be used as a dynamic
library:
-
In the Library painter, place in one standard
PowerBuilder library (a PBL file)
all the objects that you want in the dynamic library.If you need to create a new library, select Entry>Library>Create
from the menu bar, then drag or move the objects into the new library. -
Make sure the application’s library search
path includes the new library.
Multiple dynamic libraries
You can use as many dynamic libraries as you want in an application.
To do so, create a source library (PBL file)
for each of them.
Specifying the dynamic libraries in your project
When you define your project, you tell PowerBuilder which
of the libraries in the application’s library search path
will be dynamic by checking the PBD or DLL check box next to the
library name in the Project painter.
Including
additional resources for a dynamic library
When building a dynamic library, PowerBuilder does not inspect
the objects; it simply copies the compiled form of the objects into
the dynamic library. Therefore, if any of the objects in the library
use resources (pictures, icons, and pointers)—either
specified in a painter or assigned dynamically in a script—and
you do not want to provide these resources separately, you must
list the resources in a PowerBuilder resource (PBR) file. Doing
so enables PowerBuilder to include the resources in the dynamic
library when it builds it.
To reference additional resources:
-
List the resources in a PBR file, as described
in “Using PowerBuilder
resource files”. -
Use the Resource File Name box in the Project
painter workspace to reference the PBR file in the dynamic library.