Difference between revisions of "Structure"
|Line 1:||Line 1:|
Revision as of 12:21, 3 January 2007
|This page is under development as part of the EPrints 3.4 manual. It may still contain content specific to earlier versions.|
This is a definition of some terms used in the eprints documentation and comments. Many of these are "objects" within the code and the perl module which handle them is listed.
An archive is a eprints archive with it's own website configuration and data. One install of the eprints software can run serveral seperate archives. Sharing code but with totally different configurations. Before EPrints 2.4 this was known as EPrints::Archive. This was changed to avoid confusion with the eprint status of "archive".
A session is created every time a cgi script or a bin script is executed, and terminated afterwards.
An eprint is a record in the system which has one or more documents and some metadata. Usually, more than one document is to provide the same information in multiple formats, although this is not compulsary. Pre 2.4 this was known as EPrints::EPrint.
A document is a single format of an eprint, eg. HTML, PDF, PS etc. It can contain more than one file, for example HTML may contain more than one html page + image files. The actual files are stored in the filesystem. Pre 2.4 this was known as EPrints::Document.
A user registered with the system. (NOT necesarily the author of the eprints they deposit). Pre 2.4 this was known as EPrints::User
A subject has an id and a list of who it's parents are. There is a build in subject with the id "ROOT" to act as the top level. A subject can have more than one parent to allow you to create a rich lattice, rather than just a tree, but loops are not allowed.
- type or usertype or eprinttype
- users, eprints and documents all have a "type". This controls how they are "cited" and also for users and eprints it controls what fields may be edited, and which are required.
dataobj (aka "item")
The "super class" of subjects, users, eprints and documents etc. In the very core of the system these are all treated identically and much of the configuration and methods of these classes of "thing" are identical. We use the term item to speak about the general case.
A dataset is a collection of items of the same type. It can be searched.
Some datasets all have the same "config id". The "config id" is used to get information about the dataset from the archive config - inbox, buffer, archive and deletion all have the same metadata fields and types.
Core datasets are:
|eprint||EPrint records are the core of the system.|
|user||Users registered with the system.|
|subject||The subject tree.|
|document||Documents belonging to EPrints. Every document is part of an EPrint record.|
|subscription||Subscriptions made by users. Every subscription is a part of a Subscription record.|
|history||Stores actions performed on records.|
In addtion to these datasets are four virtual datasets: inbox, buffer, archive and deletion. These act just like "eprint" except that they are filtered to only contain records with those status.
Note that prior to 2.4 the "eprint" dataset was virtual, rather than "inbox", "buffer" etc. The History dataset was introduced in 2.4.
The connection to the MySQL back end. datasets are stored in the MySQL system, but you do not have to address it directly.
fields (or "metadata fields")
A single field in a dataset. Each dataset has a few "system" fields which eprints uses to manage the system and then any number of archive specific fields which you may configure.
Some software refers to this concept as "alerts".
A stored search which is performed every day/week/month and any new results are the mailed to the user who owns the subscription.
This diagram does not show "Subscription". Subscription is a subclass of DataObj (like EPrint, User etc.). A Subscription is associated with one User. A User is associated with 0..n Subscription's.