The CompileApp -js flag converts the 4GL modules (applications consisting of userclasses and procedures) into JavaScript modules, storing them in the specified file path. If you use -js without the -c (component) flag, all modules in the application will be transpiled (compiled and translated) into JavaScript. The -js flag implicitly forces 4GL modules to be recompiled, thus you need not specify -f (forcecompile). If the 4GL code cannot be compiled successfully for a component, no JavaScript will be generated for it.

For more information about transpiling JavaScript from 4GL, see How You Can Transpile JavaScript Modules from Your 4GL Components and Applications and Command Line Method for Compiling Applications (CompileApp).