mrm-server

An OSLC 3.0 server for the MISA Municipal Reference Model (MRM). It exposes MRM domain resources -- Programs, Services, Processes, Resources, Outcomes, Organization Units, Target Groups, and Needs -- as linked data through standard OSLC and LDP interfaces. The server is built on the oslc-service Express middleware with Apache Jena Fuseki as the triple store backend.

Prerequisites

• Node.js v22.11.0 or later
• Apache Jena Fuseki running with a dataset named mrm (or matching the jenaURL in config.json)
• The oslc4js workspace dependencies installed (this module depends on oslc-service, ldp-service-jena, and storage-service from the monorepo)

Build

From the workspace root (oslc4js/):

npm install
npm run build --workspace=mrm-server

Or from within mrm-server/:

npm run build

This runs tsc and emits compiled JavaScript to dist/.

Configuration

The server reads config.json at startup, with environment variables taking precedence where applicable.

Field	Type	Default	Description
scheme	string	"http"	URL scheme for the server base URI
host	string	"localhost"	Hostname the server binds to
port	number	3002	Port the server listens on
context	string	"/"	LDP context path (root of the OSLC service)
jenaURL	string	"http://localhost:3030/mrm/"	SPARQL endpoint URL for the Jena Fuseki dataset

The following environment variables override config.json values:

Variable	Overrides
LDP_BASE	Derives scheme, host, port, and context from a single base URL
HOSTNAME	host
VCAP_APP_HOST	Listen host (Cloud Foundry)
VCAP_APP_PORT	Listen port (Cloud Foundry)

Running

1. Start Apache Jena Fuseki with an mrm dataset:

   fuseki-server --mem /mrm

2. Start the server:

   npm start --workspace=mrm-server

   The server will print its configuration and listen on http://localhost:3002/ by default.

Web UI

mrm-server includes the oslc-browser web application, served as static files from public/. After starting the server, open your browser to:

http://localhost:3002/

The UI provides an interactive column browser for navigating MRM service providers, resources, and their relationships. To rebuild the UI after changes to oslc-browser:

cd mrm-server/ui
npm run build

This builds the Vite app shell into mrm-server/public/.

What It Does

MRM Domain Resources

The MRM (Municipal Reference Model) defines a set of resource types for describing municipal government service delivery:

Resource Type	RDF Type	Description
Program	mrm:Program	A municipal program
Service	mrm:Service	A service delivered by a program
Process	mrm:Process	A process that implements a service
Resource	mrm:Resource	A resource used by processes
Outcome	mrm:Outcome	An outcome or result of a program or service
Organization Unit	mrm:OrganizationUnit	An organizational unit responsible for delivery
Target Group	mrm:TargetGroup	A target group served by a program or service
Need	mrm:Need	A need addressed by programs or services

OSLC Capabilities

For each resource type above, the server provides:

• Creation Factories -- POST a new resource to create it in the triple store
• Query Capabilities -- GET with OSLC query syntax to find resources
• Resource Shapes -- defined in config/shapes/MRMS-Shapes.ttl (referenced but managed by oslc-service)
• Delegated UI Dialogs -- creation dialogs for each resource type, served from the dialog/ directory

Diagram Support

The server also supports OMG DD (Diagram Definition) diagrams via the dd: namespace. Diagram creation factories and creation dialogs are provided for:

Organization Unit, Program, Service, Process, Resource, Need, Outcome, Output, Target Group, PLM, and SIAM diagrams.

Diagram shapes are defined in config/shapes/MRMS-DiagramShapes.ttl. A selection dialog is also available for choosing existing diagrams.

Architecture

mrm-server
  |-- src/app.ts           Entry point: creates Express app, mounts oslc-service
  |-- src/env.ts           Configuration resolution (config.json + env vars)
  |-- config.json          Default server configuration
  |-- config/
  |     |-- catalog-template.ttl    OSLC ServiceProviderCatalog template
  |     +-- shapes/                 Resource shape definitions (Turtle)
  +-- public/              Static files (built navigator UI)

The server is a thin domain-specific layer on top of two shared libraries:

• oslc-service -- Express middleware that reads catalog-template.ttl and provides the OSLC ServiceProviderCatalog, ServiceProviders, creation factories, query capabilities, resource shapes, and delegated UI dialogs.
• ldp-service-jena -- JenaStorageService implementation of the StorageService interface. Handles all LDP container and resource CRUD operations against a Jena Fuseki SPARQL endpoint.

The catalog-template.ttl file in config/ defines the full OSLC service description using placeholder URIs (urn:oslc:template/...). At startup, oslc-service processes this template, replaces placeholders with the server's actual base URL, and exposes the resulting catalog at the server root.

REST API

The server exposes standard LDP and OSLC 3.0 REST endpoints:

• GET / -- OSLC ServiceProviderCatalog
• GET /serviceProviders/{id} -- Individual ServiceProvider
• GET /shapes/{shapeName} -- Resource shape documents
• POST /{container}/ -- Create a resource (via creation factory)
• GET /{container}/ -- Query resources (supports oslc.where, oslc.select, oslc.prefix)
• GET /{container}/{resourceId} -- Read a single resource
• PUT /{container}/{resourceId} -- Update a resource
• DELETE /{container}/{resourceId} -- Delete a resource

Content negotiation supports text/turtle, application/ld+json, and application/rdf+xml.

See the oslc-server README for detailed LDP and OSLC protocol documentation.

License

Apache-2.0