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Fedora In-context: �Front-ends

Islandora, Hydra and Custom

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Learning Outcomes

Front-end options (Hydra, Islandora, custom)

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Similarities and differences

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Opportunities for interoperability

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Islandora

From 1.x into the CLAW

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  • Launched in 2006 at the University of Prince Edward Island
  • Islandora Foundation created in 2013 as steward of code
  • Provides a standards-based, open source platform with a sustainable approach to long-term data stewardship
  • Provides a sustainable software ecosystem via an active and diverse community of developers and users
  • 60+ Solution Packs and two yearly releases

Introduction to Islandora

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Islandora 7.x-1.x Software Stack

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DRUPAL 7.X �(CMS, Presentation, Workflows)

Islandora (MIDDLEWARE)

Fedora 3.8.1 (Storage and preservation)

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Islandora CLAW Ecosystem

Multi Language

Distributed

Role Separation

Not a layer

https://github.com/Islandora-CLAW

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Islandora CLAW Ecosystem

Chullo PHP Fedora 4 Connector/Wrapper class - client

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Crayfish Silex Microservice, uses Chullo and exposes REST endpoints

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PDX Silex Microservice, uses Crayfish and exposes PCDM utility REST endpoints

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Alpaca Event-driven middleware based on Apache Camel that synchronizes Drupal content to a triple store.

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Salmon Event-driven middleware based on Apache Camel that synchronizes a Fedora 4 repository with a Drupal instance.

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Islandora CLAW Design Goals

  • We have a MVP to rule them all!

Big picture: Utilize Fedora 4/ Drupal 8 to their fullest

  • Easier to install
  • Easier to develop and contribute
  • Expose Linked Data
  • Easier to use
    • Enhanced user experience
    • Faster searching, display, and ingest
    • Expose more control of your repository through UI

● Easier to scale



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Islandora CLAW Methods

  • Installation bash scripts or Docker
  • Vagrant development environment
  • Tight Drupal 8 integration / UX RDF to Entities Mapping
  • Modal bi-directional Sync / JSON-LD based REST API
  • Asynchronous interactions via Camel
  • Transformation logic in the UI
  • Decoupling
  • Independent PHP Microservices / Silex
  • Data modelling out of the Source Code

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Using Apache Camel

Camel is a framework for building middleware

  • Provides workflow-like structure for the code
  • Routes can be written in multiple languages
  • Message splitting, transformations, concurrent processing, error handling / redelivery
  • Works out of the box with everything you can think of
  • Used by Islandora for JMS Processing, bi-directional Sync and more
  • Runs on Karaf/ OSGI

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CLAW Diagram

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PHP Microservices and Silex

Slim/Lightweight Fedora 4 RESTful API wrappers

  • Silex apps deal with HTTP/Routing/LDP �and upper level Resource constructs
  • Chullo: Fedora 4 Client Library deals with Fedora 4 interaction
  • Modern PHP, based on a Kernel and Event propagation
  • Dependency Injection allows further decoupling
  • Microservices can live in a distributed system
  • Simple to code, extendable and fast (PHP7)
  • Drupal 8 is Symfony. Silex is subset of Symfony

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https://github.com/Islandora-CLAW/CLAW

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Hydra

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What is Hydra?

  • A robust repository fronted by feature-rich, tailored applications and workflows (“heads”)
    • One body, many heads
  • Collaboratively built “solution bundles” that can be adapted and modified to suit local needs
  • A community of developers and adopters extending and enhancing the core
    • If you want to go fast, go alone. If you want to go far, go together.

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Ruby on Rails

  • Rapid application development for web applications: “Convention over configuration”
  • Supportable: MVC (Model-View-Controller) and Rails framework make code well-structured, predictable
  • Testable: RSpec and Cucumber give powerful, automatable, testing tools
  • Learnable: Stanford went from 1 to 8 Ruby savvy developers in one year (no new hires)

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Current Developments

  • PCDM modeling
  • Layered approach for configurability
  • Rails isn't required until CurationConcerns
  • Sufia and CurationConcerns may merge
  • Makes a deep stack even deeper

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For More Information

Duraspace Wiki:

ProjectHydra:

  • https://projecthydra.org/ (may be outdated)

GitHub:

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Custom Implementations

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Extending Fedora

Islandora and Hydra are not the only options

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REST-API can be used to build customizations

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Extending Fedora 4 presentations on Day 3

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Interoperability

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Interoperability Considerations

  • Common Fedora, can view all resources
  • Common recipes for Camel integrations
    • Indexing: Triplestore, Solr, etc.
    • derivative generation: PCDM Use Extension
  • Common structural Ontologies, like PCDM (primer)

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Where are we now?

  • Adopting WebAC as an authorization standard
  • Discussing common PCDM usage
  • Next: Common services?
    • API-X

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Current Fedora 4 Implementations

A list of known Fedora 4 implementations can be found on the wiki:

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https://wiki.duraspace.org/display/FF/Fedora+4+Implementations