openehr-sdt

The openEHR Simplified Formats for Rust: FLAT and STRUCTURED composition reading and writing, Web Template building, TDD import, template-independent RM-instance validation, and the SMART on openEHR scope grammar. Hand-written over the openehr-its wire layer (Apache-2.0).

The name comes from the Simplified Data Template specification (docs/specs/openehr/ITS-REST/docs/simplified_data_template/), the ITS-REST document family these formats grew out of. As of ITS-REST Release 1.1.0 that document is marked RETIRED in favour of the Simplified Formats specification, and Simplified Formats is what this crate implements.

What it provides

• openehr_sdt::flat: the Simplified Formats. FLAT and STRUCTURED data instances, the Web Template model and builder, and the TDD to COMPOSITION converter. The authority is the STABLE ITS-REST 1.1.0 Simplified Formats specification (docs/specs/openehr/ITS-REST/docs/simplified_formats/): master04 for field identifiers, the node-id algorithm and the FLAT/STRUCTURED algorithms, master05 for the per-RM-type mapping tables, master06 for the ctx/ vocabulary. The entry points are in flat::convert: composition_from_flat, composition_to_flat, composition_from_structured, composition_to_structured, flat_to_structured and structured_to_flat, each converting against a flat::webtemplate::model::WebTemplate. The submitted_composition_from_flat and submitted_composition_from_structured variants add the master04 §Validation input-side checks a submitted body runs.
• openehr_sdt::rm_instance: template-independent validation of a whole RM instance tree. validate_rm_and_terminology runs the RM-invariant and terminology passes, validate_composition composes the template-driven pass of flat::validation over them, and both report ValidationMessage values.
• openehr_sdt::smart_scopes: the SMART on openEHR resource-scope grammar (docs/specs/openehr/ITS-REST/docs/smart_app_launch/master08-scopes.adoc), plus the launch-context scopes of master07 §Context Selection and master09 §Experimental: Episode Context. The parser is total: a scope string the grammar does not recognise becomes SmartScope::Other and is kept inert.

The SM SIM-B and SDF model documents are DEVELOPMENT-state and are not implemented; their terse string encodings are not accepted. No vendor implementation is used as an oracle.

Parsing a scope claim

use openehr_sdt::smart_scopes::SmartScope;

let scopes = SmartScope::parse_all("openid patient/composition-*.cru");
for scope in &scopes {
    if let SmartScope::Resource(resource) = scope {
        assert!(resource.permissions.read);
        assert!(!resource.permissions.delete);
    }
}

Features

With default-features = false and nothing else the crate compiles to smart_scopes alone, with no dependency of any kind. A browser client can then parse SMART scope strings with the same grammar a server enforces.

On wasm32-unknown-unknown

$ cargo add openehr-sdt --no-default-features --features flat

That selection carries the Simplified Formats and the RM-instance validation; cache stays out. For the scope grammar alone, drop --features flat. FerroEHR's CI checks both selections for that target on every code change.

Hand-written, not generated

Everything in this crate is hand-written. The specifications it implements are prose sub-specifications of ITS-REST with no machine-readable model to generate from. It consumes the generated openehr-rm and openehr-am types and the canonical JSON entry points of openehr-its directly, and never re-models the RM.

Versioning

The package version is the crate's own independent SemVer line. It tracks this implementation's code and moves freely with fixes and improvements, never with the vendored openEHR specification. The implemented spec version is available at runtime as the crate-level constant openehr_sdt::SPEC_VERSION ("1.1.0", the ITS-REST release that Simplified Formats and SMART App Launch belong to), independent of the package version.

Minimum supported Rust version

Rust 1.98 (edition 2024).

License

Business Source License 1.1 (LICENSE, SPDX BUSL-1.1), the licence of the FerroEHR application: all non-production use is free, production use is free for Non-Commercial Purposes, and any other production use, hosting for third parties or distribution for a fee needs a commercial licence from the Licensor, Cadasto B.V.: write to info@cadasto.com or use https://www.cadasto.com/contact/. Each version becomes Apache License 2.0 four years after it is published. The crate is hand-written; the openEHR specification text it implements is the authority but is not embedded in the package. The crate was first published at 0.0.68, built against the 0.0.67 siblings; from 0.0.69 it moves in lockstep with them. Its code was published as part of openehr-its before that.

Part of FerroEHR

This crate is the Simplified Formats layer of FerroEHR, a pure-Rust, openEHR-spec-conformant Clinical Data Repository (ITS-REST 1.1.0 + AQL 1.1 on PostgreSQL 18). The crates are usable standalone; FerroEHR is the reference consumer.