Hl7.Cql.Packager

HL7 CQL Packager

A .NET tool that packages CQL, ELM, and build outputs into a FHIR Library resource.

Overview

The HL7 CQL Packager performs the following steps:

1. Translation: Converts ELM JSON files into Linq.Expressions, then translates these expressions into C# code. Each ELM file is converted into a class, with each function within that file becoming a public method in the class.
2. Compilation: Compiles the generated C# code into a single assembly per ELM file.
3. Packaging: Packages the assembly (and optionally the original CQL, ELM, and C# source code) into a FHIR Library resource, creating one resource per original ELM file.

Getting Started

Installation

Install the packager tool globally using the following command:

dotnet tool install Hl7.Cql.Packager --global --prerelease

Note: The --prerelease option is required because only prerelease versions are currently available.

Prerequisites

The tool does not convert CQL into ELM. You need to use the existing Java-based tooling for this conversion.

Usage

Run the tool with the following command:

cql-package --elm <directory> --cql <directory> [options]

Mandatory Parameters

• --elm <directory>: Specifies the root directory for the ELM files. This parameter is required.
• --cql <directory>: Specifies the root directory for the CQL files. This parameter is required.

Optional Parameters

• [--fhir <directory>]: Specifies the output directory for the FHIR resources
• [--cs <directory>]: Specifies the output directory for generated C# code
• [--cs-typeformat <var|explicit>]: Specifies whether to use 'var' (default) or explicit types in the generated C# output
• [--dll <directory>]: Specifies the DLL output directory
• [--log-debug <true|false>]: Enable debug logging or not (default)
• [--canonical-root-url <url>]: Specifies the root url used for the resource canonical. If omitted a '#' will be used.
• [--override-utc-date-time <ISO8601-date-time>]: Defines the UTC date to override in the generated FHIR resource libraries (example: 2000-12-31T23:59:59.99Z). If omitted the current date time will be used.

Example

cql-package --elm Elm\json --cql Cql\input --fhir c:\packager-output-fhir --cs c:\packager-output-cs

This command packages the ELM and CQL files from the specified directories and writes the generated FHIR Resources and C# code to the respective directories.

Further Reading

The CQL Packager tool is part of the Firely CQL SDK. More information can be found at Firely’s documentation site.