Elevate Web Builder supports basic compiler define functionality. Compiler defines are symbols used to conditionally include or exclude code in the compilation process, and can be tested at compile-time to make such a determination. Compiler defines are taken into account during the parsing phase of the compilation process.

Defining Symbols

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You can create a compiler define using the following syntax:

{$DEFINE <Symbol>}

Once a symbol has been defined, it will be effective for the remaining code in the current unit. Defining a symbol that is already defined does nothing.


You can use the Project Options in the IDE to create application-wide compiler defines. Please see the Modifying Project Options topic for more information.

Un-Defining Symbols

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You can remove a compiler define using the following syntax:

{$UNDEF <Symbol>}

Testing for Defined Symbols

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To test whether a symbol has been defined, you can use the following syntax:

{$IFDEF <Symbol>}
// Include this code if the symbol is defined
[{$ELSE}]
// Include this code if the symbol is not defined (optional)
{$ENDIF}

To test whether a symbol has not been defined, you can use the following syntax:

{$IFNDEF <Symbol>}
// Include this code if the symbol is not defined
[{$ELSE}]
// Include this code if the symbol is defined (optional)
{$ENDIF}

An IFDEF or IFNDEF test must always be terminated with an ENDIF. The ELSE conditional branch is optional.

Built-In Defines

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Elevate Web Builder includes several built-in compiler defines that control various aspects of how the component library and applications are built:


Example

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The following is code from the standard component library that tests for the special DESIGN symbol to determine whether to use the WebDesign (IDE run-time) or the WebDOM (browser run-time) unit:

{$IFDEF BROWSER}
uses WebDOM;
{$ENDIF}
{$IFDEF SERVER}
uses WebSrvr;
{$ENDIF}