Training Video:Virtual Fields

Introduction

Walkthrough of adding a metadata field to a repository.

Virtual Meta Fields are fields that are not stored in the database, instead their input and output can be programmed. They can be used whenever a default displayed value is not what the user needs. Since their value is calculated their uses are limited by one's imagination. It should be stressed out that Virtual Fields are not only limited to displaying values, they can be used for setting values as well.

Except from Virtual Fields, this video touches other useful areas of EPrints as well, like how to write an EPrints script using the API, how fields are rendered, etc.

What you will learn

Watching this video will teach you:

• How and when to use Virtual Fields
• How to add a new field (Virtual Field in this example)
• How a Virtual Field's value is rendered
• How to correctly override an EPrints' function (render_value in this example)
• How to use the Core API Wiki
• How abstracts are refreshed and re-generated
• How the citation's summary page is edited
• How to create and run a simple script using EPrints' API
• How to return a value from a Virtual Field
• How to inherit MetaField.pm class to create a new field type and override some of its functions
• How to create a virtual field based on a newly generated field type

What you should already know

• basic understanding of EPrints tree structure (http://wiki.eprints.org/w/EPrints_Directory_Structure_Tree)
• basic understanding of EPrints configuration files (http://wiki.eprints.org/w/EPrints_Directory_Structure/eprints3/archives/ARCHIVEID/cfg/cfg.d)
• basic understanding of Eprints administrative commands (http://wiki.eprints.org/w/API:bin/epadmin)

More Reading

• Metatada fields (http://wiki.eprints.org/w/Category:EPrints_Metadata_Fields)