Home Library 2.0 API Framework Specification

Home Library 2.0 API

The Home Library is a library to manage and persist the user home folders that supports file sharing.

Any Home Library user is presented with a personal Workspace [Add link to the workspace portlet], 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.

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 build on the top of the Jackrabbit web application. 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 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.

Objects removed

• AquaMapsItem
• Annotation
• DocumentLink
• ImageDocumentLink
• PDFDocumentLink
• Annotation
• TabularDataLink
• ExternalResourceLink
• WorkflowReport
• WorkflowTemplate

Objects mapped to gCubeItem

• Document
• ImageDocument
• Metadata
• PDFDocument
• UrlDocument

Use the next section to keep code compatible with both old and new API.

Compatibility

There is some pattern to know during the transition period to keep code base compatible with both old and new API.

If using old API 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());

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

How to

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>

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