LDP

This package allows you to setup LDP containers in which LDP resources can be manipulated.

Features

• Handles triples, turtle and JSON-LD format
• Automatic creation of containers on server start
• Full container management: create, attach resources, detach, clear, delete...

Dependencies

• ApiGateway
• JsonLDService
• OntologiesService
• TripleStoreService

Sub-services

• LdpResourceService
• LdpContainerService
• LdpLinkHeaderService
• LdpRegistryService
• LdpApiService (internal)
• LdpCacheService (internal)

Mixins

• ControlledContainerMixin
• DocumentTaggerMixin
• ImageProcessorMixin
• DisassemblyMixin

Install

$ yarn add @semapps/ldp

Usage

const { LdpService } = require('@semapps/ldp');

module.exports = {
  mixins: [LdpService],
  settings: {
    baseUrl: 'http://localhost:3000/',
    containers: [
      {
        path: '/resources'
        // Specific container options (See below)
      }
    ],
    defaultContainerOptions: {
      // See below
    }
  }
};

Settings

Property	Type	Default	Description
baseUrl	String	required	Base URL of the LDP server
containers	[Object]	required	List of containers to set up, with their options (see below)
defaultContainerOptions	[Object]		Default options for all containers (see below)
mirrorGraphName	String	"http://semapps.org/mirror"	Name of the RDF graph where to store mirrored data
podProvider	Boolean	false	Set to true if your server is a POD provider
preferredViewForResource	Function		Function called to generate a redirect to the preferred view (see below)
resourcesWithContainerPath	Boolean	true	If true, the URI of all new resources will include the container path

Container options

The following options can be set for each container, or they can be set in the defaultContainerOptions settings.

Property	Type	Default	Description
accept	String	"text/turtle"	Type to return (application/ld+json, text/turtle or application/n-triples)
acceptedTypes	Array		RDF classes accepted in this container. This is not enforced but used by some services to identify containers.
excludeFromMirror	Boolean	false	If true, other servers will not be able to mirror this container.
activateTombstones	Boolean	true	If true, and if the ActivityPubService setting is also true, Tombstones will replace deleted resources.
permissions	Object \| (webId, ctx) => Permissions		If the WebACL service is activated, permissions of the container itself. For the permissions object shape, see webacl.resource.addRights action.
newResourcesPermissions	Object \| (webId, ctx) => Permissions		If the WebACL service is activated, permissions for new resources. See the docs here
readOnly	Boolean	false	Do not set POST, PATCH, PUT and DELETE routes for the container and its resources
preferredView	String		A part of the final URL for redirecting to the preferred view of the resource (see below).
controlledActions	Object		Use custom actions instead of the LDP ones (post, list, get, create, put, patch, delete). Used by the ControlledContainerMixin

API routes

These catch-all routes are automatically added to the ApiGateway service.

Method	LDP resource	LDP container
GET	ldp.resource.get	ldp.container.get
POST	ldp.resource.post	ldp.container.post
PUT	ldp.resource.put	-
PATCH	ldp.resource.patch	ldp.container.patch
DELETE	ldp.resource.delete	ldp.container.delete

Note: If the readOnly container option is set (see above), only GET routes are added.

Redirecting to a frontend app

When a browser visits the URL of an LDP resource, for example https://data.yourserver.com/users/alice, with an Accept header containing text/html, you have the ability to redirect the browser to your preferred view on the frontend of your application.

In order to configure this feature, you should add the following configurations :

1. For each container that you want to setup a redirect, add the preferredView option:

const containers = [
  {
    path: '/users',
    preferredView: '/Person/',
    // Other container options...
  },
  { ... }
];

2. Set the preferredViewForResource setting with a function like this one which will receive the preferredView option set above:

function preferredViewForResource(resourceUri, containerPreferredView) {
  if (!containerPreferredView) return resourceUri;
  return 'https://yourfrontend.com' + containerPreferredView + encodeURIComponent(resourceUri) + '/show';
}

The function should return the redirect link. It can be async. Return resourceUri if you want to cancel the redirect.

Actions

The following service actions are available:

getBaseUrl

Allow other services to get access to the baseUrl setting of the LDP server.

Return values

The baseUrl setting.