goodboy008/labelize/zpl-reference

ZPL Official Reference Lookup

Purpose

Fetch and interpret ZPL command specifications from the official Zebra Programming Guide to resolve ambiguities in labelize's ZPL parser and renderer.

When to Use

• A rendered label doesn't match expected output
• Implementing or fixing a ZPL command parser
• Unsure about parameter defaults, ranges, or optional values
• Command interaction behavior is unclear (e.g., ^FO vs ^FT, ^BY defaults)
• Adding support for a new ZPL command

Official Documentation

Base URL: https://docs.zebra.com/us/en/printers/software/zpl-pg/c-zpl-zpl-commands.html

Command Page URL Pattern

Each ZPL command has a dedicated page. The URL follows this pattern:

https://docs.zebra.com/us/en/printers/software/zpl-pg/c-zpl-zpl-commands/r-zpl-<slug>.html

Common Command Slugs

Supplementary Pages

Procedure

1. Identify the command — Extract the ZPL command prefix (e.g., ^BC, ^FO, ^GB) from the user's question or from the parser code.

1. Fetch the official doc — Use the #tool:fetch_webpage tool to load the command's page:

`` https://docs.zebra.com/us/en/printers/software/zpl-pg/c-zpl-zpl-commands/r-zpl-<slug>.html ``

1. Extract key details:

• Parameter list with positions, types, defaults, and valid ranges
• Interaction notes (e.g., "this command is affected by ^BY")
• Default behavior when parameters are omitted

1. Compare with labelize implementation:

• Search the parser for how the command is parsed: grep_search for the command prefix in src/parsers/
• Check the element struct in src/elements/
• Check the renderer logic in src/drawers/renderer.rs

1. Report discrepancies between the official spec and labelize's implementation.

Example

User asks: "Why is my Code 128 barcode too wide?"

1. Fetch https://docs.zebra.com/us/en/printers/software/zpl-pg/c-zpl-zpl-commands/r-zpl-bc.html
2. Check ^BC parameters: orientation, height, print interpretation line, above/below, UCC check digit, mode
3. Fetch https://docs.zebra.com/us/en/printers/software/zpl-pg/c-zpl-zpl-commands/r-zpl-by.html
4. Check ^BY defaults: module width (default 2), wide-to-narrow ratio (default 3.0), bar height (default 10)
5. Search labelize parser for ^BY handling — verify defaults match
6. Report findings