EPrints 3 Technical Overview

1
EPrints 3 Technical Overview

• EPrints 3 Briefing
• 8th December 2006, London

2
Overview

• Getting EPrints 3 up and running
• Installation
• Upgrading
• Configuring deposit process
• workflow
• autocompletion
• Plugging in functionality
• import, export, screen, input component
• New XML Format
• Improved indexer
• Web service interface

3
Installation

• Download from releases section of
  files.eprints.org
• Platform requirements
• Unix (Red Hat Linux recommended)
• Core software requirements
• apache 2, mod_perl, perl, mysql
• Expertise requirements
• basic webmaster skills
• some Unix experience
• confident editing text and XML configuration
  files

4
Installation Run epadmin Tool

• Walks you through creating an EPrints 3
  repository
• core configuration
• hostname, repository name
• database configuration
• creates database
• creates EPrints 3 tables in database
• creates an initial user account
• username, user type, password
• creates repository Web pages
• Open repository homepage in browser log in

5
Upgrading

• EPrints 3 is a very significant upgrade
• You will need to migrate your EP2 configuration
  to EP3
• But dont worry, there is a tool to help you
  migrate
• install EP3 on same server as your EP2 repository
• run migration tool
• creates copy of your database and configuration
• converts them to EP3
• run EP2 and EP3 in parallel
• make sure all the changes you made to your EP2
  repository are reapplied to your EP3 repository
• switch to EP3 as your production repository
• Vanilla repositories will migrate with little or
  no intervention
• More advanced repository configurations will need
  some manual inspection

6
Running an EPrints Repository

• Keep operating system patched
• Keep EPrints and plugins up to date
• Regularly back up repository data and
  configuration

7
Getting Help with Installation/Migration

• Step by step instructions
• wiki.eprints.org
• Technical mailing list
• www.eprints.org/software/
• EPrints Services
• Build and host
• Assess and manage migration process
• www.eprints.org/services/

8
Configuring Deposit Process

• Workflow flexibility
• Autocompletion options

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Workflow Flexibility

• EP3 workflows should feel familiar
• defined using XML
• divided into stages (pages)
• More flexible
• group related fields together
• file upload can appear at any stage in workflow
• fields or groups can be collapsed by default
• text can be inserted into the workflow
• e.g. additional instructions, notices

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Workflow Flexibility Flow Control

• EP3 also supports conditional workflow
• eg. workflow variations for
• different types of eprint
• different sorts of users
• different kinds of journals
• different publication stages
• eg. if unpublished dont need volume, number pages

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Workflow Flexibility Example

• A department within your institution wants to use
  its own classification scheme in addition to your
  default scheme
• Add new scheme to workflow with conditional
• check which department the depositor comes from
• if the department matches maths then include
  the additional classification scheme in the
  workflow

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Workflow Flexibility Example XML
ltstage name"subjects"gt ltcomponent
type"FieldSubject"gt ltfield ref"subjects"
required"yes" /gt lt/componentgt ltepcif
test"userid.as_item()department maths'"gt
ltcomponent type"FieldSubject"gt ltfield
refmaths_subjects" required"yes"/gt
lt/componentgt lt/epcifgt lt/stagegt
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Autocompletion

• EPrints 3 autocompletes
• author names
• journal title
• also fills in publisher and ISSN
• ISSN
• also fills in journal title and publisher
• conference title
• also fills in location and date
• Where are these being looked up?
• existing eprints in the repository
• the more populated your repository, the more
  suggestions users will see

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Autocompletion Custom Lookups

• Provide a text file (authority list)
• a list of names, titles, ...
• additional display information
• eg. ROMEO authority list
• list of journal titles
• publisher policy also displayed
• community will share at files.eprints.org
• Write a custom lookup script to
• query external resource/service
• eg. staff database
• eg. Library of Congress name authority service

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Autocompletion Workflow

• Autocompletion can be combined with workflow
  conditionals
• eg. if user is from School of Medicine, look up
  grant name (and id) in MRC database
• eg. if user is from Computer Science department
  look up authors in ACM authority list

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Autocompletion How Lookup Works

• Lookup script is passed the characters that the
  depositor has typed
• Must return matching results as HTML list items

ltligt J Smith (author of 6 items in this
repository) ltulgt ltli id"forvaluerelative
_name_family"gtSmithlt/ligt ltli
id"forvaluerelative_name_given"gtJlt/ligt
ltli id"forvaluerelative_id"gtjs_at_gmail.comlt/ligt
lt/ulgt lt/ligt
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Plugging In Functionality

• EPrints 3 functionality can be extended with
  plugins
• import and export
• get data in and out of the repository
• interface screens
• add new tools and reports to UI
• input components
• add new ways for users to enter data
• Key design goals
• Easy to build
• minimal coding
• Easy to share
• drop in and go
• distribute independently of EPrints

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Plugins Writing an Export Plugin

• Register
• name
• will appear on search results page
• what it can handle
• lists of records or single records (or both)
• type of record (eprint, user, subject...)
• who can use it
• Define 2 core functions
• how EPrints record maps to export record
• field mapping
• how to serialise export record into export format

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Plugins Import Plugins

• Reading input can be harder than writing output
• detect and handle errors in input
• But there are many existing libraries available
  for parsing a wide variety of file formats

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Plugins Writing an Import Plugin

• Register
• name
• what it can handle
• who can use it
• Define 2 core functions (export backwards)
• deserialise import record from import format
• map import record to eprints record

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Plugins Screen Plugins

• Drop new tools, actions and reports into the
  EPrints UI

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Plugins Writing Screen Plugins

• Register
• where it appears in UI
• who can use it
• Define functionality
• for example...

23
Plugins Writing Screen Plugins (2)

• New tool available to users
• eg. RAE utilities

User tools list
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Plugins Writing Screen Plugins (2)

• New action to be invoked on an eprint
• eg. scan documents for viruses

Eprint actions list for depositors (there is also
an actions list for editors)
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Plugins Writing Screen Plugins (3)

• New report about an eprint
• eg. show download statistics

Eprint tabs list (each tab is a single screen
plugin)
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Plugins Input Component Plugins

• Drop custom input controls into the deposit
  workflow
• eg. pick latitude and longitude coordinates from
  a map
• eg. draw a molecule in an applet

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Plugins Writing Input Component Plugins

• Define 2 core functions
• how to render input control(s)
• how to update the record based on what the user
  entered
• Optionally define
• how to check the user input is valid

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EPrints 3 XML Format

• New XML format for import and export
• Much more succinct than EP2 format
• Embedded documents
• document metadata alongside eprint metadata
• files themselves can be included inline
• base64 encoded
• export your whole repository as 1 single XML file
• All record types can be imported/exported in this
  format
• eprints, users, subjects, history, access log...

29
EPrints 3 Indexer

• EP2 indexer used the Forth bridge model
• index everything then start again
• EP3 introduces index queue
• on-demand indexing
• much less resource intensive!
• queues individual metadata fields or files to be
  indexed rather than entire records
• whenever a record changes, the values that got
  changed are added to the queue
• Deposits are indexed sooner

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EPrints 3 Web Service

• Deposit, retrieve, search and remove records
  remotely
• Currently not part of EPrints 3 core
• development team working on security model
• ensure actions only carried out by authorised
  users
• testing with various platforms
• available on request

31
Contributing to EPrints 3

• files.eprints.org
• for the latest
• plugins
• authority lists and autocomplete lookup scripts
• subject trees
• translations
• themes (skins)
• other tools, utilities