fop-core

XSL-FO document parser and property system for the COOLJAPAN FOP ecosystem. This crate reads XSL-FO XML and produces a typed, arena-allocated FO tree with property inheritance.

Version: 0.1.1 | Release Date: 2026-04-20

Features

• 294 XSL-FO 1.1 properties as a compile-time enum (PropertyId)
• Property inheritance with parent chain lookup and caching
• Arena-allocated FO tree with index-based handles (no Rc<RefCell<>>)
• SAX-like streaming parser built on quick-xml
• 29 FO element types covering pages, blocks, tables, lists, graphics
• Shorthand expansion for margin, padding, border shorthands
• Nesting validation per XSL-FO 1.1 specification rules

Installation

Add fop-core to your Cargo.toml:

[dependencies]
fop-core = "0.1"

Or via the command line:

cargo add fop-core

Usage

Parsing an XSL-FO Document

use fop_core::FoTreeBuilder;
use std::io::Cursor;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let xml = r#"<?xml version="1.0"?>
<fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">
    <fo:layout-master-set>
        <fo:simple-page-master master-name="A4"
            page-width="210mm" page-height="297mm">
            <fo:region-body margin="1in"/>
        </fo:simple-page-master>
    </fo:layout-master-set>
    <fo:page-sequence master-reference="A4">
        <fo:flow flow-name="xsl-region-body">
            <fo:block font-size="14pt">Hello, FOP!</fo:block>
        </fo:flow>
    </fo:page-sequence>
</fo:root>"#;

    let builder = FoTreeBuilder::new();
    let arena = builder.parse(Cursor::new(xml))?;

    for (id, node) in arena.iter() {
        println!("{}: {}", id, node.data.element_name());
    }

    Ok(())
}

Property Inheritance

Properties are looked up through a parent chain. Inheritable properties (like font-size, color) automatically propagate from parent to child:

use fop_core::{PropertyId, PropertyValue, PropertyList};
use fop_types::Length;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mut parent = PropertyList::new();
    parent.set(PropertyId::FontSize, PropertyValue::Length(Length::from_pt(14.0)));

    let child = PropertyList::with_parent(&parent);
    // child inherits font-size=14pt from parent
    if let Some(size) = child.get(PropertyId::FontSize) {
        println!("Inherited font-size: {:?}", size);
    }

    Ok(())
}

Architecture

Modules

properties/ — Property System

tree/ — FO Tree

xml/ — XML Parsing

elements/ — Element Definitions

Total: 4,157 lines across 16 files

Supported FO Elements (29 types)

Page Layout: Root, LayoutMasterSet, SimplePageMaster, RegionBody, RegionBefore, RegionAfter

Page Sequence: PageSequence, Flow, StaticContent

Block Level: Block, BlockContainer

Inline Level: Inline, Character, PageNumber, PageNumberCitation

Table: Table, TableColumn, TableHeader, TableFooter, TableBody, TableRow, TableCell

List: ListBlock, ListItem, ListItemLabel, ListItemBody

Other: ExternalGraphic, BasicLink, Leader, Wrapper

Tests

41 unit tests covering:

• Property ID name/number mapping
• Property value parsing (lengths, colors, enums)
• Property inheritance chains
• Shorthand expansion (margin, padding, border)
• XSL-FO document parsing (simple and complex)
• Element nesting validation
• XML namespace handling
• Arena allocator operations

Dependencies

Related Crates

License

Apache-2.0

Author

Copyright 2024-2026 COOLJAPAN OU (Team Kitasan)

Repository: https://github.com/cool-japan/fop