BizTalk - How to preserve the trailer when debatching a flat file?

So I'm parsing flat files using 3 separate schemas - a header, t开发者_JS百科railer and body. I know that you can go into flat file disassembler properties and flip "Preserve header" to true and the header is injected into the context collection... but how can I do something similar for the footer?

This is sometimes difficult to do since BizTalk reads forward only it cannot just locate the footer, so you'll need to either use a tag identifier or build a custom disassembly component based on content of the footer record.