Extension Repeater Registry entry

Output a row for each value in a table of values when exporting extension data.1

Description

A standard is defined in EMu through the creation and maintenance of two types of record in the Standards module:

Record Type	Details
Term Definition	A Term Definition record associates one or more EMu fields with a term in a standard. Multiple Term Definition records are created for each standard.
Standard	A Standard record groups Term Definitions into a single export format compliant with a particular standard.

Using the EMu Scheduled Exports facility, it is then possible to export EMu data compliant with that standard. While a typical export from EMu allows data to be exported from one or more columns, data is exported as is; it cannot be manipulated, formatted or combined with other values as it is exported. When exporting to a standard it is possible to combine, manipulate and format values from two or more columns to produce a single export value.

When we define a Standards record that groups Term Definitions for a standard, Dublin Core for instance, all of the Term Definition records must use the same module (e.g. object data from ecatalogue). If it is necessary to include records from other modules in the output of data, we define another Standard record, Audubon Core for instance (grouping relevant Term Definitions from another module, e.g. multimedia data from emultimedia) and use the Extension process to combine the two (or more) standards when defining the export.

It is only possible to combine the export of two standards if a Standard Extension Registry entry defines the relationship between the two standards.

The purpose of the Extension Repeater Registry entry

When exporting to a Standard and an extension, if one of the fields in the extension is a table of values, the values in that table are exported as a single pipe-delimited value. With the Extension Repeater Registry entry, each value in the table is exported independently of the other values.

Note: The Extension Repeater Registry entry is available in EMu 9.1 onwards.

An example will clarify what is meant by this.

We want to export object data (from ecatalogue) to the Darwin Core standard with an extension of the Audubon Core standard in order to include multimedia data (from emultimedia).

Data is exported to the Darwin Core standard from five fields. The Term Definitions for these are:

dwc:DateCreated
dwc:DateCreatedUTC
dwc:Identifier
dwc:Title
dwc:Material

Alongside this data, a pair of fields is exported from the extension. The Term Definitions for these are:

aud:Title
aud:ObjectIdentfier

aud:ObjectIdentfier is a table of values.

When the table includes more than one value, the values are exported together, typically separated by a pipe. In this example, aud:ObjectIdentfier holds two values and the exported XML is:

<!-- Row 1 -->

<tuple>

   <atom name="dwc:DateCreated">2014-06-25</atom>

   <atom name="dwc:DateCreatedUTC">2014-06-25T02:31:04.000+01:00</atom>

   <atom name="dwc:Identifier">2d5fcbee-9f26-4e0e-ab07-4259fdeb7d52</atom>

   <atom name="dwc:Title">[Painting] Man standing in field</atom>

   <atom name="dwc:Material">Canvas|Oil Paint</atom>

   <table>

   <!-- Row 1 -->

      <tuple>

         <atom name="aud:Title">Man standing in field</atom>

         <atom name="aud:ObjectIdentfier">2d5fcbee-9f26-4e0e-ab07-4259fdeb7d52|7c8f5f4a-63f1-11ee-8c99-0242ac120002</atom>

      </tuple>

   </table>

</tuple>

With the Extension Repeater Registry entry, the values in the table are exported separately. A row is added to the export file for each pair of fields in the extension:

<tuple>

   <atom name="dwc:DateCreated">2014-06-25</atom>

   <atom name="dwc:DateCreatedUTC">2014-06-25T02:31:04.000+01:00</atom>

   <atom name="dwc:Identifier">2d5fcbee-9f26-4e0e-ab07-4259fdeb7d52</atom>

   <atom name="dwc:Title">[Painting] Man standing in field</atom>

   <atom name="dwc:Material">Canvas|Oil Paint</atom>

   <table>

   <!-- Row 1 -->

      <tuple>

         <atom name="aud:Title">Man standing in field</atom>

         <atom name="aud:ObjectIdentfier">2d5fcbee-9f26-4e0e-ab07-4259fdeb7d52</atom>

      </tuple>

   <!-- Row 2 -->

      <tuple>

         <atom name="aud:Title">Man standing in field</atom>

         <atom name="aud:ObjectIdentfier">7c8f5f4a-63f1-11ee-8c99-0242ac120002</atom>

      </tuple>

   </table>

</tuple>

Note the replication of aud:Title.

The complete xml for this example

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE table

   <!ELEMENT table       (tuple)*>

   <!ATTLIST table

      name        CDATA #REQUIRED

   <!ELEMENT tuple       (table|tuple|atom)*>

   <!ATTLIST tuple

      name        CDATA #IMPLIED

   <!ELEMENT atom        (#PCDATA)*>

   <!ATTLIST atom

      name        CDATA #REQUIRED

      type        CDATA "text"

      size        CDATA "short"

<?schema

   table "Darwin Core"

      text long dwc:DateCreated

      text long dwc:DateCreatedUTC

      text long dwc:Identifier

      text long dwc:Title

      text long dwc:Material

      table "Audubon Core"

         text long aud:Title

         text long aud:ObjectIdentifier

end

end

?>

<!-- Data -->

<table>

   <!-- Row 1 -->

   <tuple>

      <atom name="dwc:DateCreated">2014-06-25</atom>

      <atom name="dwc:DateCreatedUTC">2014-06-25T02:31:04.000+01:00</atom>

      <atom name="dwc:Identifier">2d5fcbee-9f26-4e0e-ab07-4259fdeb7d52</atom>

      <atom name="dwc:Title">[Painting] Man standing in field</atom>

      <atom name="dwc:Material">Canvas|Oil Paint</atom>

      <table>

         <!-- Row 1 -->

         <tuple>

            <atom name="aud:Title">Man standing in field</atom>

            <atom name="aud:ObjectIdentfier">2d5fcbee-9f26-4e0e-ab07-4259fdeb7d52</atom>

         </tuple>

         <!-- Row 2 -->

         <tuple>

            <atom name="aud:Title">Man standing in field</atom>

            <atom name="aud:ObjectIdentfier">7c8f5f4a-63f1-11ee-8c99-0242ac120002</atom>

         </tuple>

      </table>

   </tuple>

   <!-- Row 2 -->

   <tuple>

      <atom name="dwc:DateCreated">2014-06-26</atom>

      <atom name="dwc:DateCreatedUTC">2014-06-26T00:37:25.000+01:00</atom>

      <atom name="dwc:Identifier">7c8f5f4a-63f1-11ee-8c99-0242ac120002</atom>

      <atom name="dwc:Title">[Paintings] Landscapes with people standing in fields</atom>

      <atom name="dwc:Material">Canvas|Oil Paint</atom>

      <table>

         <!-- Row 1 -->

         <tuple>

            <atom name="aud:Title">Man standing in field</atom>

            <atom name="aud:ObjectIdentfier">2d5fcbee-9f26-4e0e-ab07-4259fdeb7d52</atom>

         </tuple>

         <!-- Row 2 -->

         <tuple>

            <atom name="aud:Title">Man standing in field</atom>

            <atom name="aud:ObjectIdentfier">7c8f5f4a-63f1-11ee-8c99-0242ac120002</atom>

         </tuple>

      </table>

   </tuple>

</table>

Usage

Key	User	Group	Group
Key 1	`User`	`Group`	`Group`
Key 2	user	group	`Default`
Key 3	`Table`
Key 4	`estandards`
Key 5	`Extension Repeater`
Key 6	Standard name
Key 7	Extension name
Value	Core Term;Extension Term

In pipe-delimited format:

`User`	user	`Table`	`estandards`	`Extension Repeater`	Standard name	Extension name	Core Term;Extension Term
`Group`	group	`Table`	`estandards`	`Extension Repeater`	Standard name	Extension name	Core Term;Extension Term
`Group`	`Default`	`Table`	`estandards`	`Extension Repeater`	Standard name	Extension name	Core Term;Extension Term

where:

Standard name

is the name of a standard recorded (Record Type = Standard) in the Standards module. The name of the standard is recorded in Name: (Extract Name).

Extension name

is the name of another standard recorded (Record Type = Standard) in the Standards module. The name of the standard is recorded in Name: (Extract Name).

Core Term;Extension Term

where:

Core Term is a field in Standard name which uniquely identifies an exported record (e.g. Object Number).
Extension Term is a field in Extension name which is a table of values.

When the Core Term is matched in Extension Term (the table of values), a row is output in the XML export file.

Explanation

In the Catalogue module:

Object A (ID1) is attached to two records in the Multimedia module, Image 1 and Image 2
Object B (ID2) is also attached to these two Multimedia records, Image 1 and Image 2

A table of values in the Multimedia records lists which objects the images are attached to:

Image 1 lists two Catalogue records:
- ID1
- ID2
Image 2 lists two Catalogue records:
- ID1
- ID2

When Aududon is an extension and we export data from this table of values, four values would be exported for Object A as the table of values in Image 1 holds two records and the table of values in Image 2 holds two records:

Image 1 from Object A (ID1)
Image 2 from Object A (ID1)
Image 1 from Object B (ID2)
Image 2 from Object B (ID2)

This is why we pair Core Term with Extension Term.

Matching Core Term (the object ID in this example) in Extension Term (the table of values) ensures that only data associated with a specific object is exported. By matching ID1 in the table of values, the output for Object A is:

Image 1 from Object A (ID1)
Image 2 from Object A (ID1)

and the output for Object B is:

Image 1 from Object B (ID2)
Image 2 from Object B (ID2)

Example

When exporting data from the Audubon Core extension, an individual row is exported for each ac:Id which is associated with the dwc:Id:

Key	Setting
Key 1	Group
Key 2	Default
Key 3	Table
Key 4	estandards
Key 5	`Extension Repeater`
Key 6	Darwin Core
Key 7	Audubon Core
Value	dwc:Id;ac:Id