Home Library 2.0 API Framework Specification
Contents
Introduction
The Home Library is a library to manage and persist the user home folder that supports file sharing.
Any Home Library user is presented with a personal Workspace, where users can collaborate, share information, and access project resources using special folders. This module describes the model of Home Library 2.0 and how to use the new API interface.
Design Model
The design model for Home Library identifies a core set of capabilities to work on Jackrabbit content. The goal of Home Library 2.0 is to expose content in the content repository as HTTP resources, fostering a RESTful style of application architecture. Home Library 2.0 is 10 times faster on average in comparison with the previous version.
The Home Library 2.0 is composed by:
- HomeLibrary: the API interface.
- HomeLibrary JCR: an HomeLibrary implementation based on JCR 2.0 (Java Content Repository JSR 283).
- HomeLibrary WebApp: a webService built on the top of the Jackrabbit web application.
- Home Library Model: a library to shared information between clients and Web App. It includes ACLType, FolderItemType, NodeProperty, WorkspaceItemType, etc.
Workspace Items
Each element contained in a workspace area is a WorkspaceItem.The workspace items are the effective user objects.
The following figure shows the WorkspaceItem model.
Prior HL 2.0 Objects that have been removed
- AquaMapsItem
- Annotation
- DocumentLink
- ImageDocumentLink
- PDFDocumentLink
- Annotation
- TabularDataLink
- ExternalResourceLink
- WorkflowReport
- WorkflowTemplate
Prior HL 2.0 Objects that have been mapped to the new model (GCubeItem)
- Document
- ImageDocument
- Metadata
- PDFDocument
- UrlDocument
Use the next section to migrate your components to the new Home Library API.
Compatibility
There is some pattern to know to keep code compatible with new API.
If you were working on Document, ImageDocument, Metadata, PDFDocument or UrlDocument, using new API your are going to work on GCubeItem that is a generic gCube Object.
But old context and model are still available using the following sections.
Document
Home Library 2.0 API to retrieve Document Objects:
import org.gcube.common.homelibrary.home.workspace.folder.items.gcube.Document; Document document = (Document) item; becomes: import org.gcube.common.homelibary.model.items.type.NodeProperty; import org.gcube.common.homelibrary.home.workspace.folder.items.GCubeItem; GCubeItem document = (GCubeItem) item;
How to retrieve properties:
document.getAlternatives(); -> document.getProperties().getProperties().get((NodeProperty.ALTERNATIVES.toString()); document.getAnnotation(); -> document.getProperties().getProperties().get((NodeProperty.ANNOTATIONS.toString()); document.getCollectionName(); -> document.getProperties().getProperties().get((NodeProperty.COLLECTION_NAME.toString()); document.getData(); -> document.getProperties().getProperties().get((NodeProperty.DATA.toString()); document.getFolderItemType(); -> document.getProperties().getProperties().get((NodeProperty.FOLDER_ITEM_TYPE.toString()); document.getLength(); -> document.getProperties().getProperties().get((NodeProperty.SIZE.toString()); document.getMetadata(); -> document.getProperties().getProperties().get((NodeProperty.METADATA.toString()); document.getMimeType(); -> document.getProperties().getProperties().get((NodeProperty.MIME_TYPE.toString()); document.getParts(); -> document.getProperties().getProperties().get((NodeProperty.PARTS.toString()); document.getURI(); -> document.getProperties().getProperties().get((NodeProperty.OID.toString()); document.getWorkflowData(); -> document.getProperties().getProperties().get((NodeProperty.WORKFLOW_DATA.toString()); document.getWorkflowId(); -> document.getProperties().getProperties().get((NodeProperty.WORKFLOW_ID.toString()); document.getWorkflowStatus(); -> document.getProperties().getProperties().get((NodeProperty.WORKFLOW_STATUS.toString());
ImageDocument
New Home Library API to retrieve ImageDocument Objects:
import org.gcube.common.homelibrary.home.workspace.folder.items.gcube.ImageDocument; ImageDocument document = (ImageDocument) item; becomes: import org.gcube.common.homelibary.model.items.type.NodeProperty; import org.gcube.common.homelibrary.home.workspace.folder.items.GCubeItem; GCubeItem document = (GCubeItem) item;
To retrieve properties, use the API for Document Object and the following API:
document.getHeight(); -> document.getProperties().getProperties().get((NodeProperty.IMAGE_HEIGHT.toString()); document.getWidth(); -> document.getProperties().getProperties().get((NodeProperty.IMAGE_WIDTH.toString()); document.getThumbnailHeight(); -> document.getProperties().getProperties().get((NodeProperty.THUMBNAIL_HEIGHT.toString()); document.getThumbnailWidth(); -> document.getProperties().getProperties().get((NodeProperty.THUMBNAIL_WIDTH.toString()); document.getThumbnail(); -> document.getProperties().getProperties().get((NodeProperty.THUMBNAIL_DATA.toString()); document.getThumbnailLength(); -> document.getThumbnail().getSize();
Metadata
New Home Library API to retrieve Metadata Objects:
import org.gcube.common.homelibrary.home.workspace.folder.items.gcube.Metadata; Metadata document = (Metadata) item; becomes: import org.gcube.common.homelibary.model.items.type.NodeProperty; import org.gcube.common.homelibrary.home.workspace.folder.items.GCubeItem; GCubeItem document = (GCubeItem) item;
To retrieve properties:
document.getURI(); -> document.getProperties().getProperties().get((NodeProperty.OID.toString()); document.getWorkflowData(); -> document.getProperties().getProperties().get((NodeProperty.WORKFLOW_DATA.toString()); document.getWorkflowId(); -> document.getProperties().getProperties().get((NodeProperty.WORKFLOW_ID.toString()); document.getWorkflowStatus(); -> document.getProperties().getProperties().get((NodeProperty.WORKFLOW_STATUS.toString()); document.getSchemaName(); -> document.getProperties().getProperties().get((NodeProperty.SCHEMA.toString()); document.getXML(); -> document.getProperties().getProperties().get((NodeProperty.ALTERNATIVES.toString()); document.getCollectionName(); -> document.getProperties().getProperties().get((NodeProperty.COLLECTION_NAME.toString()); document.getURI(); -> document.getProperties().getProperties().get((NodeProperty.OID.toString());
PDFDocument
New Home Library API to retrieve PDFDocument Objects:
import org.gcube.common.homelibrary.home.workspace.folder.items.gcube.PDFDocument; PDFDocument document = (PDFDocument) item; becomes: import org.gcube.common.homelibary.model.items.type.NodeProperty; import org.gcube.common.homelibrary.home.workspace.folder.items.GCubeItem; GCubeItem document = (GCubeItem) item;
To retrieve properties, use the API for Document Object and the following API:
document.getNumberOfPages(); -> document.getProperties().getProperties().get((NodeProperty.NUMBER_OF_PAGES.toString()); document.getVersion(); -> document.getProperties().getProperties().get((NodeProperty.VERSION.toString()); document.getAuthor(); -> document.getProperties().getProperties().get((NodeProperty.AUTHOR.toString()); document.getTitle(); -> document.getProperties().getProperties().get((NodeProperty.PDF_TITLE.toString()); document.getProducer(); -> document.getProperties().getProperties().get((NodeProperty.PRODUCER.toString());
UrlDocument
New Home Library API to retrieve UrlDocument Objects:
import org.gcube.common.homelibrary.home.workspace.folder.items.gcube.UrlDocument; UrlDocument document = (UrlDocument) item; becomes: import org.gcube.common.homelibary.model.items.type.NodeProperty; import org.gcube.common.homelibrary.home.workspace.folder.items.GCubeItem; GCubeItem document = (GCubeItem) item;
To retrieve properties, use the API for Document Object and the following API:
document.getUrl(); -> document.getProperties().getProperties().get((NodeProperty.URL.toString());
Properties and Types
Properties and Types are in Home Library Model, so update the package as follows:
org.gcube.common.homelibrary.home.workspace.WorkspaceItemType -> org.gcube.common.homelibary.model.items.type.WorkspaceItemType org.gcube.common.homelibrary.home.workspace.folder.FolderItemType -> org.gcube.common.homelibary.model.items.type.FolderItemType org.gcube.common.homelibrary.home.workspace.accessmanager.ACLType -> org.gcube.common.homelibary.model.items.type.ACLType
Implementation Framework
The Home Library 2.0 API is a set of components that uses Apache Jackrabbit, to store and manage content.
Home Library 2.0 uses Java servlets to process HTTP requests in a RESTful way.
Home Library is implemented in terms of the JCR API. The default implementation for Apache Jackrabbit is provided out of the box.
Through code sharing, the framework reduces development costs and ensures the consistency and correctness of library implementations.
Management Model
The core of Home Library 2.0 is a web application built on top of Jackrabbit.
Home Library WebApp uses Java servlets to process HTTP requests coming from clients. The servlets are a frontend to the actual operations and they support the following operations:
- retrieve content
- create content
- modify existing content
- remove existing content
- move existing content to a new location
- copy existing content to a new location
Using the Home Library
To use Home Library 2.0, import the following dependencies:
<dependency> <groupId>org.gcube.common</groupId> <artifactId>home-library-jcr</artifactId> <version>[2.0.0-SNAPSHOT,3.0.0-SNAPSHOT)</version> </dependency> <dependency> <groupId>org.gcube.common</groupId> <artifactId>home-library</artifactId> <version>[2.0.0-SNAPSHOT,3.0.0-SNAPSHOT)</version> </dependency>
How to retrieve the user Home
Firs of all is necessary to retrieve an instance of HomeManagerFactory, this can be done using the static methods from HomeLibrary class.
HomeManagerFactory factory = HomeLibrary.getHomeManagerFactory();
Obtained the factory you can retrieve the HomeManager:
HomeManager manager = factory.getHomeManager();
Then we retrieve the User home:
User user = manager.createUser(portalLogin); Home home = manager.getHome(user,scope);
Where portalLogin is the user username used to login into the portal (for test you can use any username) and scope can be a GCUBEScope object or a GCUBEScope expression (for test you can use any expression).
At this point we can get the Workspace with his root:
Workspace ws = home.getWorkspace(); WorkspaceFolder root = ws.getRoot();