ESciDoc Container Toc

TOC Representation based on RSS 1.0

In eSciDoc hierarchical structures are build by means of container resources. A container resource refers to its members which are again containers or items. The set of references is represented as structural map (struct-map) inside the representation of a container resource. Additionally a container may contain a table of content (TOC) which contains an ordered selection of members. The TOC does not allow the grouping of members. It contains only direct members of the container resource. Grouping of direct members is not necessary; a hierarchical structure is build by container resources wich are linked as members.

The only reason to provide more than one TOC for a container resource would be to have different selections of the container resource members. It is assumed that there is no use case for different selections of members of one single container.

A TOC consists of a RSS items element which is "an RDF table of contents" Template:Citation containing an ordered list of member resources. The items element contains an RDF sequence (rdf:Seq) with RDF list items (rdf:li). A list item referes to a member resource by the RDF resource attribute.

<rss:items>
	<rdf:Seq>
		<rdf:li rdf:resource="http://localhost:8080/ir/item/escidoc:234"/>
		<rdf:li rdf:resource="http://localhost:8080/ir/container/:111"/>
	</rdf:Seq>
</rss:items>

toc-view

If the toc-view of a container resource is requested, a RSS channel is generated for delivery. The channels about attribute is set to the containers URL; title and description are set to the containers title and description. The link element of the channel contains the URL of the requested toc-view. Further the content of the containers TOC is added (rss:items) and a RSS item for each TOC entry is added.

An item element contains information about the refered member (rdf:about attribute). At least an item contains the title, description and URL of the member resource as rss:title, rss:description and rss:link. Additionally all DC entries from the triplestore pertaining the refered member are added.

<?xml version="1.0"?>
<rdf:RDF 
    xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" 
    xmlns:rss="http://purl.org/rss/1.0/" 
    xmlns:dc="http://purl.org/dc/elements/1.1/">

  <rss:channel rdf:about="http://localhost:8080/ir/container/escidoc:123">
    <rss:title>The containers title</rss:title>
    <rss:link>http://localhost:8080/ir/container/escidoc:123/resources/toc-view</rss:link>
    <rss:description>A selected list of the members of the container.</rss:description>

    <!--
      From RDF Site Summary (RSS) 1.0 (http://web.resource.org/rss/1.0/spec#s5.3.5)
  
      5.3.5 <items>
      An RDF table of contents, associating the document's items [5.5] 
      with this particular RSS channel. Each item's rdf:resource {item_uri}
      must be the same as the associated item element's rdf:about {item_uri}.

      An RDF Seq (sequence) is used to contain all the items rather than an 
      RDF Bag to denote item order for rendering and reconstruction. 
    -->
    <rss:items>
      <rdf:Seq>
        <rdf:li rdf:resource="http://localhost:8080/ir/item/escidoc:234"/>
        <rdf:li rdf:resource="http://localhost:8080/ir/container/:111"/>
      </rdf:Seq>
    </rss:items>
		
    <rss:item rdf:about="http://localhost:8080/ir/item/escidoc:234">
      <rss:title>Title of the refered resource</rss:title>
      <rss:link>http://localhost:8080/ir/item/escidoc:234</rss:link>
      <rss:description>Description from the refered resource</rss:description>
      <!-- All dc metadata entries from triplestore. -->
      <dc:title>Title from DC</dc:title>
      <dc:identifier>Identifier from DC</dc:identifier>
    </rss:item>

    <rss:item rdf:about="http://localhost:8080/ir/container/escidoc:111">
      <!-- ... -->
    </rss:item>

  </rss:channel>
</rdf:RDF>

Questions & Discussion

• we have discovered a new use case (coming up from VIRR project, for more info please check VIRR Pages) for table of contents (the TOC for e.g. scanned books should contain the whole structure of a container i.e. there is one single TOC for the whole top-level container e.g. book)
• we would probably need to remove the TOC datastream from Containers (as it is valid for a single level only) and count with a separate "TOC object"
• in case we create separate TOC objects that can be related to a container, we should also provide a utility to "generate initial TOC" based on the Container structure (starting from a specific container node and traversing through all other nodes). The utility in fact can generate (RSS lists as depicted already with the toc-view? METS document?).
• syncronization of TOC objects with the Container structure
  • alternative: generated TOC is not automatically in sync with the real structure of the container. Utility for validating the TOC structure based on the container structure can be provided. The modification of a container is not automatically changing/invalidating the TOC.
  • alternative: generated TOC is always in sync with the real structure of the container. Modification of a container validates related TOC objects (is not modifying them but marks them as invalid). Users who are then responsible for TOC object editing should re-generate the TOC object by using a system utility.
  • alternative: generated TOC is always in sync with the real structure of the container. Modification of a container validates related TOC objects, removes nodes no longer existing in the container structure and adds nodes new in the container structure. Users who are then responsible for TOC object editing may manually remove TOC object node(s).

• another requirement coming up from the same project: we need to establish "logical" order of elements in the container (in addition to the "structural" grouping. The logical order should depict something like book with book pages (both sides of a page in case the page is printed only one-sided and on the back side there are some remarks, comments):
  • previous object
  • current object
    • current object-recto
    • current object-verso
  • next object
    • next object-recto
    • next object-verson

In a real example, this would mean that the logical order is the "labeling" (in the example marked with bold), and the physical order is the "numbered order as understood by a machine" (in the example marked with italic) e.g. :

Example 1:

• Book (top level node, no labeling, no numbering yet)
  • Book Chapter I - 1
  • Book Chapter II - 2
    • Page A - 2.1
    • Page B - 2.2
    • Page B-1 - 2.3
  • Book Chapter III -3

Example 2:

• Encyclopedia (top level node, no labeling, no numbering yet)
  • Part A-M - 1
  • Part N-T - 2
  • Part U-Z - 3

Example 3a:

• Architectural drawings collection of N.N. (top level node, no labeling, no numbering yet)
  • • Drawing XII - 1.1 - foreface - recto
    • Drawing XII - 1.2 - backface - verso

Example 3b:

• Architectural drawings collection of N.N. (top level node, no labeling, no numbering yet)
  • • Drawing XII - 1 - (image of foreface, image of backface)

Note: example 3 (a, b) is here not very well thought trough: as we are not yet certain if both foreface and backface would be considered as separate objects like depicted above or as separate components of a same object.

Whether we do it in a container or we try to depict it with the TOC object only - it is something we need to clarify.

• TOC objects - to be considered as a possibility to have more than one TOC object for a container? What happens with TOC (html), TOC(rtf)? etc. Is this subject to the representation of the TOC only?

Table of Contents

Really Simple Syndication

Enhanced Scientific Documentation

Resource Description Framework

Uniform Resource Locator

Dublin Core

Virtueller Raum Reichsrecht

Metadata Encoding and Transmission Standard