A converter must not crash on bad input. Implement:
Log every conversion: input XML fingerprint, output ZPL size, warnings (e.g., "Text truncated").
The most practical deployment is a lightweight web server (Flask/FastAPI in Python, or Express in Node.js). The endpoint accepts XML and returns ZPL:
POST /convert Content-Type: application/xml<order>...your xml...</order>
--- Response --- Content-Type: text/plain ^XA^LL400...^XZxml to zpl converter
Your warehouse software can then POST the XML and pipe the response directly to the printer using a raw socket connection.
Store a JSON mapping file that defines the ZPL structure and variable injection points:
"template": "^XA^LL400^PW800",
"fields": [
"xml_path": "shipping/recipient/name", "zpl": "^FO50,50^A0,40^FDvalue^FS" ,
"xml_path": "shipping/recipient/address", "zpl": "^FO50,100^A0,30^FDvalue^FS" ,
"xml_path": "order/items/item/sku", "zpl": "^FO600,300^BY3^BQN,100^FDQA,value^FS"
],
"footer": "^XZ"
Your converter then walks the XML, replaces value in the template, and concatenates the results. A converter must not crash on bad input
Use this if you are reviewing an open-source script, API, or NuGet package.
Title: Lightweight and Functional, but Needs Documentation Rating: ★★★☆☆
Summary: This library provides a bare-bones approach to converting XML to ZPL. It handles the basics well but lacks the robustness required for complex enterprise labeling without significant modification.
What Works:
Room for Improvement:
Conclusion: A great starting point for simple projects. If you need to print basic address labels from an XML feed, this works out of the box. For complex RFID labeling or image handling, be prepared to fork the repo and write your own extensions.
| Feature | Why it matters |
|---------|----------------|
| Printer-specific tuning | ZPL differs between Zebra GK420d and ZT610 (^MD, ^PR) |
| RFID encoding | XML → ^RF block for EPC Gen2 |
| PDF417 split across labels | Large data + small label |
| Digital signature injection | For compliance labels (GS1, UDI) |
| Metric ↔ dots conversion | Input mm → internal dots (e.g., 203 DPI = 8 dots/mm) |