Elm bindings for Morphir


Keywords
morphir, elm, business-logic, code-generation, modeling
License
Apache-2.0
Install
npm install morphir-elm@2.32.0

Documentation

morphir-elm

morphir-elm

Morphir is a multi-language system built on a data format that captures an application's domain model and business logic in a technology agnostic manner. This repo contains tools that allow you to write your business logic in Elm, parse it into Morphir IR and transpile it to other languages like Scala or visualize it to your business users using Elm.

We publish it both as an NPM and an Elm package:

Package Overview

  • The NPM package contains the CLI for running the tools as part of your build.
  • The Elm package supports multiple use-cases:
    • It includes SDK functions that you can use while writing your business logic beyond the default elm/core support.
    • It provides a type-safe API to work with the Morphir IR directly. You can use this to add your own logic builder, visualization or language transpiler.
    • It also provides access to the frontend that parses the Elm source code and returns Morphir IR. You could use this to embed a business logic editor in your web UI.

NPM package

npm version

The morphir-elm NPM package provides a CLI to run the tooling.

Installation

npm install -g morphir-elm

Usage

All the features can be accessed through sub-commands within the morphir-elm command:

Usage: morphir-elm [options] [command]

Options:
  -v, --version  output the version number
  -h, --help     output usage information

Commands:
  make           Translate Elm sources to Morphir IR
  gen            Generate code from Morphir IR
  develop        Start up a web server and expose developer tools through a web UI
  help [cmd]     display help for [cmd]

Each command has different options which are detailed below:

morphir-elm make

This command reads Elm sources, translates to Morphir IR and outputs the IR into JSON.

Usage: morphir-elm make [options]

Translate Elm sources to Morphir IR

Options:
  -p, --project-dir <path>  Root directory of the project where morphir.json is located. (default: ".")
  -o, --output <path>       Target file location where the Morphir IR will be saved. (default: "morphir-ir.json")
  -h, --help                output usage information

Important: The command requires a configuration file called morphir.json located in the project root directory with the following structure:

{
    "name": "My.Package",
    "sourceDirectory": "src",
    "exposedModules": [
        "Foo",
        "Bar"
    ]
}
  • name - The name of the package. The package name should be a valid Elm module name and it should be used as a module prefix in your Elm models. If your package name is My.Package all your module files should either be directly under that or in submodules.
  • sourceDirectory - The directory where your Elm sources are located.
  • exposedModules - The list of modules in the public interface of the package. Module names should exclude the common package prefix. In the above example Foo refers to the Elm module My.Package.Foo.

Examples

If you want to try the make command you can use the reference model we have under tests-integration/reference-model. Simply cd into the directory and run the command.

morphir-elm gen

This command reads the JSON produced by morphir-elm make and generates code into the specified folder:

Usage: morphir-elm gen [options]

Generate code from Morphir IR

Options:
  -i, --input <path>              Source location where the Morphir IR will be loaded from. (default: "morphir-ir.json")
  -o, --output <path>             Target location where the generated code will be saved. (default: "./dist")
  -t, --target <type>             Language to Generate (Scala | SpringBoot | cypher | triples). (default: "Scala")
  -e, --target-version <version>  Language version to Generate. (default: "2.11")
  -c, --copy-deps                 Copy the dependencies used by the generated code to the output path. (default: false)
  -h, --help                      output usage information

Examples

If you want to try the gen command you can use the reference model we have under tests-integration/reference-model. Simply cd into the directory and run the command.

morphir-elm develop

This command relies on the JSON produced by morphir-elm make and brings up a web server to browse the Morphir IR.

Usage: morphir-elm develop [options]

Start up a web server and expose developer tools through a web UI

Options:
  -p, --project-dir <path>  Root directory of the project where morphir.json is located. (default: ".")
  -h, --help                output usage information

Examples

If you want to try the develop server you can use the reference model we have under tests-integration/reference-model. Simply cd into the directory and run the command.

Elm package

Latest version of the Elm package

The finos/morphir-elm package provides various tools to work with Morphir. It contains the following main components:

  • The Morphir SDK which provides the base set of types and functions that Morphir tools support out-of-the-box. (the SDK is a superset elm/core with a few exceptions documented below)
  • A type-safe API for the Morphir IR that allows you to create or inspect it.

Installation

elm install finos/morphir-elm

Morphir SDK

The goal of the Morphir.SDK module is to provide you the basic building blocks to build your domain model and business logic. It also serves as a specification for backend developers that describes the minimum set of functionality each backend implementation should support.

It is generally based on elm/core/1.0.5 and provides most of the functionality provided there except for some modules that fall outside the scope of business knowledge modeling: Debug, Platform, Process and Task.

Apart from the modules mentioned above you can use everything that's available in elm/core/1.0.5 without importing the Morphir SDK. The Elm frontend will simply map those to the corresponding type/function names in the Morphir SDK.

The Morphir SDK also provides some features beyond elm/core/1.0.5. To use those features you have to import the specific Morphir SDK module.

Morphir IR

The Morphir.IR module defines a type-safe API to work with Morphir's intermediate representation. The module structure follows the structure of the IR. Here's a list of concepts in a top-down approach:

  • Distribution is the output of morphir-elm make. It represents a whole package with all of its dependencies.
  • Package represents a set of modules that are versioned together.
  • Module is a container to group types and values.
  • Types allow you to describe your domain model.
  • Values allows you to describe your business logic.
  • Names provide a naming convention agnostic representation for all nodes that can be named: types, values, modules and packages. Names can be composed into hierarchies:
  • AccessControlled is a utility to define visibility constraints for modules, types and values

Contributing

Contribution Guide

  1. Fork it (https://github.com/finos/morphir-elm/fork)
  2. Create your feature branch (git checkout -b feature/fooBar)
  3. Read our contribution guidelines and Community Code of Conduct
  4. Commit your changes (git commit -am 'Add some fooBar')
  5. Push to the branch (git push origin feature/fooBar)
  6. Create a new Pull Request

NOTE: Commits and pull requests to FINOS repositories will only be accepted from those contributors with an active, executed Individual Contributor License Agreement (ICLA) with FINOS OR who are covered under an existing and active Corporate Contribution License Agreement (CCLA) executed with FINOS. Commits from individuals not covered under an ICLA or CCLA will be flagged and blocked by the FINOS Clabot tool. Please note that some CCLAs require individuals/employees to be explicitly named on the CCLA.

Need an ICLA? Unsure if you are covered under an existing CCLA? Email help@finos.org

Publishing new releases

Steps for publishing a new release

License

Copyright 2014 Morgan Stanley

Distributed under the Apache License, Version 2.0.

SPDX-License-Identifier: Apache-2.0