Crate kael_office 

kael_office

kael_office is Kael’s portable, byte-only OOXML/OPC foundation for .docx, .xlsx, and .pptx files. The same crate runs on native targets and wasm32-unknown-unknown: it detects the package type, validates and lists ZIP parts, reads and safely mutates raw parts, exposes core properties and package relationships, extracts common document/sheet/slide text, and writes a deterministic archive.

use kael_office::{OfficePackage, OfficeText};

let package = OfficePackage::open(bytes)?;
match package.extract_text()? {
    OfficeText::Document(document) => println!("{} paragraphs", document.paragraphs.len()),
    OfficeText::Spreadsheet(book) => println!("{} sheets", book.sheets.len()),
    OfficeText::Presentation(deck) => println!("{} slides", deck.slides.len()),
}
let deterministic_download = package.to_bytes()?;

Security and resource bounds

Input and exported packages are limited to 256 MiB, with at most 65,536 parts, 64 MiB per expanded part, 256 MiB total expanded data, a bounded compression ratio, validated UTF-8 relative part names, no duplicate names, no encrypted entries, no path traversal, and bounded XML event/depth/output work. DTDs are rejected. These checks substantially reduce accidental and hostile resource amplification, but applications handling adversarial files should still parse in a worker or sandbox.

Deliberate compatibility boundary

This crate is an OPC container and extraction layer, not a Word, Excel, or PowerPoint rendering engine. It does not implement Office layout, formulas, calculation, charts, macros, tracked changes, embedded-object execution, pagination, font substitution, or pixel-faithful import. Text extraction covers Word paragraph text, ordinary/shared/inline spreadsheet cell values, and slide paragraph text. Raw unknown parts and relationship parts are preserved byte for byte when the package is rewritten, while ZIP ordering, compression, metadata, and timestamps are normalized for deterministic output.

Part mutation is intentionally low level. Callers are responsible for keeping [Content_Types].xml, relationship parts, and semantic references consistent when adding or removing parts. replace_part is the safest editing primitive because it preserves the package graph.

License

Licensed under the Apache License, Version 2.0.

Structs

CellText

One extracted spreadsheet cell.

CoreProperties

Dublin Core and OPC core properties from docProps/core.xml.

DocumentText

Extracted Word paragraph content.

OfficePackage

A bounded in-memory OOXML/OPC package shared by desktop and browser builds.

OfficePart

Metadata for one OPC package part.

PackageRelationship

One OPC relationship entry.

PresentationText

Extracted presentation content.

SheetText

Extracted cells for one worksheet.

SlideText

Extracted content for one slide.

SpreadsheetText

Extracted workbook content.

Enums

OfficeFormat

The detected OOXML application format.

OfficeText

Format-specific text extracted without performing layout or calculation.