Parcels
Parcels are external file representations of packages.
An Examples Browser is provided as a parcel in the examples directory. Several image level switches are available to specify parcel loading on image startup. The parcel path is the list of directories where VisualWorks looks for parcels. This can be set using the System Settings tool.
Parcels provide the component technology for VisualWorks. Packages and bundles organize the code and model the contents of parcels. Parcels are created by publishing packages/bundles. The term components, in the VisualWorks sphere, is used to refer to parcels, packages, and bundles when it is not necessary to be specific.
The parcel code's organization on loading is determined by its creation. If it was created by publishing a package, it is loaded into the same package. If created from a bundle, it can be reloaded as the bundle or as one package.
The load sequence for a package is:
- Any prerequisite components are loaded.
- Any defined pre-load action is performed (e.g. undeclared variables initialized).
- Objects in the package are installed.
- Every class in the parcel is sent message postLoad: thePackage, and any action executed. This is often an application launch.
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