Registering Identifier Patterns

When writing unpackers, OFRAK Contributors can leverage the MagicMimeIdentifier and MagicDescriptionIdentifier by registering mappings between resource tags and mime or description patterns. Doing so will ensure that Resource.unpack automatically calls their custom unpacker.

For example, consider the following magic description identification registration in the file containing a UImageUnpacker:

MagicDescriptionIdentifier.register(UImage, lambda s: s.startswith("u-boot legacy uImage"))

This line ensures that the MagicDescriptionIdentifier adds a UImage tag to resources matching that description pattern. As a result, any unpackers targeting a UImage will automatically run when Resource.unpack is run.

Handling External Dependencies

If the Identifier makes use of tools that are not packaged in modules installable via pip from PyPI (commonly command-line tools), these dependencies must be explicitly declared as part of the identifier's class declaration. See the Components Using External Tools doc for information on how to do that.