Generic handling of metadata/Faces Implementation

Concepts[edit]

Faces Implementation[edit]

Faces solution will deal with the following metadata profiles each described by using the Dublin Core Application Profile (DCAP) Description Set Profile (DSP) syntax. For more information on DCAP see also DC Application Profile pages.

Natively, as Faces solution is based on the eSciDoc repository, it will be aware of items, components and thus the implementation of this generic metadata editor within Faces is not by default portable to other solutions (as they may have different understanding of properties, version history, relations, item structure etc.). The design however may be used as a template.

Another specialization used in Faces implementation: metadata records are xml-based and they are not expressed as rdf. Therefore the DSPs are expressed in their XML variant.

Faces metadata profile as DSP[edit]

<?xml version="1.0" encoding="UTF-8"?>
<DescriptionSetTemplate xmlns="http://dublincore.org/xml/dc-dsp/2008/01/14" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://dublincore.org/xml/dc-dsp/2008/01/14 E:\eSciDOC\TestMDStore\dcmi-dsp.xsd">
	<DescriptionTemplate ID="face-item" minOccurs="1" maxOccurs="1" standalone="yes">
		<ResourceClass>http://purl.org/escidoc/metadata/profiles/face-item</ResourceClass>
		<StatementTemplate ID="emotion" minOccurs="1" maxOccurs="1" type="nonliteral">
			<Property>http://purl.org/escidoc/metadata/terms/emotion</Property>
			<LiteralConstraint>
				<LiteralOption>happiness</LiteralOption>
				<LiteralOption>anger</LiteralOption>
				<LiteralOption>neutrality</LiteralOption>
				<LiteralOption>sadness</LiteralOption>
				<LiteralOption>fear</LiteralOption>
				<LiteralOption>disgust</LiteralOption>
			</LiteralConstraint>
		</StatementTemplate>
		<StatementTemplate ID="picture-group" minOccurs="1" maxOccurs="1" type="literal">
			<Property>http://purl.org/escidoc/metadata/terms/picture-group</Property>
			<LiteralConstraint>
				<LiteralOption>a</LiteralOption>
				<LiteralOption>b</LiteralOption>
			</LiteralConstraint>
		</StatementTemplate>
		<StatementTemplate ID="identifier" minOccurs="0" maxOccurs="1" type="literal">
			<Property>http://purl.org/dc/elements/1.1/identifier</Property>
		</StatementTemplate>
		<StatementTemplate ID="age" minOccurs="1" maxOccurs="1" type="literal">
			<Property>http://purl.org/escidoc/metadata/terms/age</Property>
		</StatementTemplate>
		<StatementTemplate ID="age-group" minOccurs="1" maxOccurs="1" type="literal">
			<Property>http://purl.org/escidoc/metadata/terms/age-group</Property>
			<LiteralConstraint>
				<LiteralOption>young</LiteralOption>
				<LiteralOption>middle-age</LiteralOption>
				<LiteralOption>old</LiteralOption>
			</LiteralConstraint>
		</StatementTemplate>
		<StatementTemplate ID="gender" minOccurs="1" maxOccurs="1" type="literal">
			<Property>http://purl.org/escidoc/metadata/terms/gender</Property>
			<LiteralConstraint>
				<LiteralOption>female</LiteralOption>
				<LiteralOption>male</LiteralOption>
			</LiteralConstraint>
		</StatementTemplate>
	</DescriptionTemplate>
</DescriptionSetTemplate>

Diamonds metadata profile as DSP[edit]

<?xml version="1.0" encoding="UTF-8"?>
<DescriptionSetTemplate  xmlns="http://dublincore.org/xml/dc-dsp/2008/01/14" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://dublincore.org/xml/dc-dsp/2008/01/14 .\dcmi-dsp.xsd">
	<DescriptionTemplate ID="diamond-item" minOccurs="1" maxOccurs="1" standalone="yes">
		<ResourceClass>http://purl.org/escidoc/metadata/profiles/diamond-item</ResourceClass>
		<StatementTemplate ID="diamond-elements" minOccurs="1" maxOccurs="1" type="literal">
			<Property>http://purl.org/escidoc/metadata/terms/diamond-elements</Property>
		</StatementTemplate>
		<StatementTemplate ID="shape" minOccurs="1" maxOccurs="1" type="literal">
			<Property>http://purl.org/escidoc/metadata/terms/shape</Property>
		</StatementTemplate>
		<StatementTemplate ID="color" minOccurs="1" maxOccurs="1" type="literal">
			<Property>http://purl.org/escidoc/metadata/terms/color</Property>
		</StatementTemplate>
		<StatementTemplate ID="mechanism" minOccurs="1" maxOccurs="1" type="literal">
			<Property>http://purl.org/escidoc/metadata/terms/mechanism</Property>
		</StatementTemplate>
		<StatementTemplate ID="condition" minOccurs="1" maxOccurs="1" type="literal">
			<Property>http://purl.org/escidoc/metadata/terms/condition</Property>
		</StatementTemplate>
		<StatementTemplate ID="temperature" minOccurs="1" maxOccurs="1" type="literal">
			<Property>http://purl.org/escidoc/metadata/terms/temperature</Property>
			<LiteralConstraint></LiteralConstraint>
		</StatementTemplate>
		<StatementTemplate ID="brief-details" minOccurs="1" maxOccurs="1" type="literal">
			<Property>http://purl.org/dc/elements/description</Property>
		</StatementTemplate>
		<StatementTemplate ID="full-details" minOccurs="1" maxOccurs="1" type="literal">
			<Property>http://purl.org/dc/terms/abstract</Property>
		</StatementTemplate>
		<StatementTemplate ID="date" minOccurs="1" maxOccurs="1" type="literal">
			<Property>http://purl.org/dc/elements/date</Property>
			<LiteralConstraint><SyntaxEncodingScheme>http://www.w3.org/TR/NOTE-datetime</SyntaxEncodingScheme></LiteralConstraint>
		</StatementTemplate>
		<StatementTemplate ID="identifier" minOccurs="1" maxOccurs="1" type="literal">
			<Property>http://purl.org/dc/elements/1.1/identifier</Property>
		</StatementTemplate>
		<StatementTemplate ID="creator" minOccurs="0" maxOccurs="1" type="nonliteral">
			<Property>http://purl.org/escidoc/metadata/terms/creator</Property>
			<NonLiteralConstraint descriptionTemplateRef="person"/>
		</StatementTemplate>
	</DescriptionTemplate>
	<DescriptionTemplate ID="person" minOccurs="1" maxOccurs="1" standalone="no">
		<ResourceClass>http://purl.org/escidoc/metadata/profiles/person</ResourceClass>
		<StatementTemplate ID="complete-name" minOccurs="1" maxOccurs="1" type="literal">
			<Property>http://purl.org/escidoc/metadata/terms/complete-name</Property>
		</StatementTemplate>
		<StatementTemplate ID="given-name" minOccurs="1" maxOccurs="1" type="literal">
			<Property>http://purl.org/escidoc/metadata/terms/given-name</Property>
		</StatementTemplate>
		<StatementTemplate ID="family-name" minOccurs="1" maxOccurs="1" type="literal">
			<Property>http://purl.org/escidoc/metadata/terms/family-name</Property>
		</StatementTemplate>
		<StatementTemplate ID="organization" minOccurs="0" maxOccurs="1" type="nonliteral">
			<Property>http://purl.org/escidoc/metadata/terms/organization</Property>
			<NonLiteralConstraint descriptionTemplateRef="organization"/>
		</StatementTemplate>
		<StatementTemplate ID="identifier" minOccurs="1" maxOccurs="1" type="literal">
			<Property>http://purl.org/escidoc/metadata/terms/identifier</Property>
			<LiteralConstraint> 
				<SyntaxEncodingScheme>http://escidoc.mpg.de/metadataprofile/schema/0.1/idtypes</SyntaxEncodingScheme>
			</LiteralConstraint> 
		</StatementTemplate>
	</DescriptionTemplate>
	<DescriptionTemplate ID="organization" minOccurs="1" maxOccurs="1" standalone="no">
		<ResourceClass>http://purl.org/escidoc/metadata/profiles/organization</ResourceClass>
		<StatementTemplate ID="organization-name" minOccurs="1" maxOccurs="1" type="literal">
			<Property>http://purl.org/escidoc/metadata/terms/organization-name</Property>
		</StatementTemplate>
		<StatementTemplate ID="address" minOccurs="0" maxOccurs="1" type="literal">
			<Property>http://purl.org/escidoc/metadata/terms/address</Property>
		</StatementTemplate>
		<StatementTemplate ID="identifier" minOccurs="1" maxOccurs="1" type="literal">
			<Property>http://purl.org/escidoc/metadata/terms/identifier</Property>
		</StatementTemplate>
	</DescriptionTemplate>
</DescriptionSetTemplate>

Administration utility[edit]

Register profile
- checks provided DSP file and validates it in accordance with the DSP.xsd
- puts provided DSP file to space defined by the user e.g. resource directory visible to the solution (JBoss deployment conf directory)

Screen configurator
- checks provided DSP file and validates it in accordance with the DSP.xsd
- generates default screen configuration for the DSP, based on screen configuration schema. For each DSP 1 file is generated and it contains 5 identical screen configurations:
  - view
  - edit
  - search
  - browse
  - export
- checks provided screen configuration file (note: can be created without help of the screen configurator) and validates it in accordance with the screen-config.schema and related DSP file
- puts provided screen-config file to space defined by the user e.g. resource directory visible to the solution (JBoss deployment conf directory)

ScreenManager (extension, see below)

Directory structure (to be discussed)
- Jboss deployment directory/conf (e.g. /usr/share/jboss/server/default/conf/ )
  - dsp/DSP-profile-id (e.g. /usr/share/jboss/server/default/conf/dsp/face-item-profile.xml, /usr/share/jboss/server/default/conf/dsp/diamond-item-profile.xml )
    - screens (e.g. /usr/share/jboss/server/default/conf/dsp/face-item/screens/face-item-sc.xml, /usr/share/jboss/server/default/conf/dsp/diamond-item/screens/diamond-item-sc.xml )

Presentation components[edit]

XMLBeans based
Schemas for XMLBeans Document objects generation:
- item.xsd (includes md-records.xsd, components.xsd) (escidoc-core)
- item-scr.xsd (derived from item.xsd, and includes respective {md-records, components, metadata}-scr.xsd, md-records-scr.xsd, components-scr.xsd, netadata-scr.xsd

Simplified sequence diagram
- Note: includes only interactions on Faces solution level, and does not include the Admin utility

User requests to view a specific face-item
Faces solution retrieves the item from the core-service and transforms it to an XMLBean object

The Faces architecture itself to be checked, maybe having a "smart" ItemBean instead of ItemHandler utility would be better (todo: check GrantVO concept and implementation).

Faces solutions checks the metadata profile version, reads the screen configuration for "view" screen and invokes the ScreenManager to deliver a respective ItemScreenBean object
ScreenManager processes the input data and creates respective ItemScreenBean object
Faces solution retrieves the ItemScreenBean object and generates the view (JSPF)

ScreenManager (extension)[edit]

In general, purpose is to transform a resource to screen resource
present development:
- component may be part of Faces solution, at later stage will be moved to separate interface
- takes as an input an item resource object (e.g. item.xml), desired screen configuration id (e.g. view, edit, etc.) and delivers a screen item resource object
future development:
- component should distinguish between screen-type and screen-id (e.g. screen-type is "view", screen-id may point to "brief", "detailed", "bibliographic", "article", "book" etc. )
- retrieveScreens (metadata profile [version]) - lists screens available for a metadata profile (all or specified version)
- generateScreens (resource, screen-id) - generates desired screen for a concrete resource
- retrieveResourceScreens (resource, [screen-type]) - lists screens available for a resource (based on its metadata profile version) (all or specified screen-type)

Implementation[edit]

Status: In progress.
Schemas:
- Dublin Core Description Set Schema, slightly modified to allow redundant statement IDs at different levels (todo: change target namespace)
- Item screen schema
- Components screen schema
- Metadata records screen schema
- Metadata profile screen configuration schema

Resources:
- Simple Face item view screen configuration
- Faces item formatted for simple view screen - i.e. basis for ItemScreenBeanObject

Limitations[edit]

Labels: Due to limitation of the DSP, it is not possible to define precise labels of a metadata in the DSP. Thus, in FACES, an extra bundle (metadata_en.properties for English) needs to be configured if labels should be different from the metadata element name itself. The key is the metadata Id define in statement template.
validation: The DSP doesn't not afford to define some validation rules. For example it is not possible to define that an age should be an integer from 18 to 99. We aim to use the eSciDoc validation service to perform metadata validation
metadata relations: Probably because of a non complete understanding of the DSP, we can't (so far!) define logical relation between metadata. For example age and age-group are not 2 different metadata but one defined in 2 ways.

i think this is not limitation of the DSP but requires modification in the metadata profile. The validation would be part of the validation service anyway --Natasa 12:35, 13 May 2009 (UTC)

Sorting/searching : We need to define for each metadata the escidoc index. We could consider that the id should be that index, but I'm not convinced it is a very good idea (regarding the complexity of certain indexes).