EPScript/Data Types

EPrints 3 Reference: Directory Structure - Metadata Fields - Repository Configuration - XML Config Files - XML Export Format - EPrints data structure - Core API - Data Objects

---

XML Configuration: EPScript - Control Format (EPC) - Citation - Workflow - Phrase - Template - XPAGE (static pages)

Data Types

EPScript has various data types, both primitive (strings, integers and booleans) and Data Objects for the various concepts that can be represented within an EPrints repository.

Primitive Types

Strings

STRING is contained within either double quotes ("") or single quotes (''). There is no difference between the two, but it may be easier to use one sort when inside an XML attribute. For example:

 <when test="type = 'patent'">
   ...
 </when>

Integers

INTEGER is defined as a string of numbers from 0-9, (e.g. 300). Leading zeros do not have any effect, and decimal values are currently not supported.

Booleans

BOOLEAN is either true or false.

Dates

DATE is defined as a string that conforms to the ISO date format (e.g. 2022-02-20),

Data Objects

Data Objects include most of the key EPrints objects - whether an EPrint itself, documents related to the EPrint, or a user. EPScript treats all of these data objects the same, with a simple approach to retrieve properties. When an EPScript is executed, a 'main' object is supplied. In the case of a citation file, this will be the item for which the citation is being created. For a workflow, this will be the object on which the workflow acts (e.g. an EPrint or a user). Properties of main objects can be accessed using a shortened approach - the following example is from a user workflow, so the usertype property is available:

 <if test="usertype = 'editor'">
   ...
 </if>

There are cases, however, where two or more data objects may be provided - such as an EPrint and a user. Here the main object can still be accessed in the short form, but other objects use a dollar notation. In this example, the EPrint is available as $eprint:

 <if test="$eprint.ispublished.one_of('unpub', 'submitted', 'inpress')"> (<print expr="$eprint.ispublished" />)</if>

Field Values

Values associated with a data object field. The field which the value belongs to can effect how it is rendered, and compared to other values.

Hashes

This currently only used by the $config parameter to give access to configuration options. Get values out of it the same way you get values from a dataobject, eg. $config{'base_url'}

Note: To use the `$config`, you may need to wrap the whole expression in braces e.g.:

  <component>
    <field ref="a_set_or_named_set_field" options="{$config{default_value_for_field}}" required="yes" />
  </component>

which would reference (in a cfg/cfg.d/example.pl file):

$c->{default_value_for_field} = "amstrad";

XHTML

The citation method returns a pre-rendered value. You can't do anything with XHTML other than print it.