Deciding Which Runtime Packages to Use

Several runtime packages, including rtl and vcl (VCL application) , supply basic language and component support. The vcl (VCL) package contains the most commonly used components; the rtl package includes all the non-component system functions and Windows interface elements. It does not include database or other special components, which are available in separate packages.

To create a client/server database application that uses packages, you need several runtime packages, including vcl, vcldb, rtl, and dbrtl (VCL) . If you want to use visual components in your application, you also need vclx (VCL) . To use these packages, choose ProjectOptions, select the Packages tab, and make sure the following list is included in the Runtime Packages edit box. You need netclx for Web server applications, as well as baseclx and probably visualclx.

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vcl;rtl;vcldb;vclx; //For VCL applications

Note: In VCL applications, you don't have to manually include vcl and rtl, because they are referenced in the Requires clause of vcldb. Your application compiles just the same whether or not vcl and rtl are included in the Runtime Packages edit box.

Another way you can determine which packages are called by an application is to run it then review the event log (choose ViewDebug WindowsEvent Log). The event log displays every module that is loaded including all packages. The full package names are listed. So, for example, for vcl90.bpl , you would see a line similar to the following in a VCL application:

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Module Load: vcl90.bpl Has Debug Info. Base Address $400B0000. Process Project1.exe ($22C)