XRechnung-for-Delphi now runs on FreePascal

[sh17]

Hey folks,

quick heads-up: I've started porting https://github.com/LandrixSoftware/XRechnung-for-Delphi (GPL lib for German/EU e-invoices — XRechnung 3.0, ZUGFeRD/Factur-X, Peppol BIS 3.0) to FreePascal. First stage is done and it actually works.

The FPC code sits next to the Delphi code via {$IFDEF FPC}, so it's one source tree. The Delphi Xml.XMLDoc write path is mapped onto fcl-xml through a tiny shim — plain FPC ≥ 3.2.2, no Lazarus needed.

And it's verified, not just "compiles": the Delphi version produces golden XML files, the FPC build regenerates them, and a canonical DOM compare says:


PASS: 102/102 golden files identical
Two FPC gotchas that ate my afternoon, in case they save yours:

umlauts in string literals → you need {$codepage utf8} in the unit (-FcUTF8 and a BOM didn't cut it for UnicodeString literals on 3.2.2).
TStringStream.DataString reinterpreted my UTF-8 as UTF-16 → garbage. TMemoryStream + UTF8ToString fixed it (same trap with Base64).
Right now it's the write path only (enough to emit every format), Windows/x86_64 tested. If there's interest, I'd be happy to tackle the read/parse path next (currently MSXML-based, hence Windows-only) and maybe take a swing at porting https://github.com/LandrixSoftware/ZUGFeRD-for-Delphi too.

Let me know if that'd be useful to anyone — and shout if you've got a preferred approach for the reader (fcl-xml XPath vs. manual DOM walk).

Sven

[zeljko]

Cool, as I can see validation cannot be done without saxon (java) ? I've done it for HR UBL 2.1 few months ago, but at the end I've created java service to do validation since calling jvm and saxon per process is pretty slow.

[sh17]

Yes, that’s true. For proper validations, I rely on valitool.org; that way, I’m certain everything is correct.

[Thaddy]

Reminds me about a time about 10 years ago where I rewrote our internal tools from Delphi to FPC...
(That was/is a BIG shop) and then we rewrote most of it in C# and the performance dropped...

Cause: licensing issue with Embarcadero for big shops....

Yes, Margreet, that was a big loss to you, I Know. I am almost out of T-shirts, do you have some?

[sh17]

I'm currently switching from Delphi to FPC. AI makes it possible—finally.