Focal Point Datatypes

This document describes the RDF vocabulary and resources for Focal Point data types (defined in the vocabulary with prefix fpdt:). Refer to Focal Point Vocabulary Prefixes for the list of all the vocabulary prefixes we use. This vocabulary is published at Focal Point Datatype Vocabulary.

See Focal Point Linked Data for information about the main Focal Point vocabulary.

High Level Design

There are two types of RDF graphs for Focal Point elements. We refer to as the generic and the natural graphs.

In the generic graph, each attribute of an element is represented as a single triple in which the subject is the URI of a fps:Element resource, the predicate is fps:memberAttribute, and the object is the URI of an fps:Attribute resource. Each fps:Attribute resource includes a single triple with predicate rdf:value and object a Focal Point datatype. This graph provides all the detail present in Focal Point and is useful for generic tools. However, this generic graph is not the one that a human designer would naturally create.

In the natural graph, each attribute of an element is represented as one or more triples in which the subject is the URI of the element resource, the predicate is URI associated with the name of the attribute, and the object is the natural one associated with the attribute. This datatype may be either a literal datatype, (e.g. xsd:integer, xsd:decimal, or xsd:boolean) or a URI to a resource whose RDF type is defined by either an external specification (e.g. FOAF or OSLC) or Focal Point (e.g. a fpdt:TimeGrid or fpdt:Matrix). The natural graph is intended to look like a typical RDF graph that might be found in an OSLC specification.

All Focal Point datatypes are subclasses of fpdt:Datatype. Most datatypes may be further classified into two groups which we refer to as the simple and the complex datatypes which correspond to subclasses fpdt:SimpleDatatype and fpdt:ComplexDatatype. An exception is fpdt:Mirror which adopts the datatype of the attribute that it mirrors.

The primary RDF values associated with the simple datatypes are given by triples that have predicate fpdt:value. A simple datatype may have zero or more fpdt:value triples. For example, fpdt:Heading always has zero fpdt:value triples and fpdt:MultiChoice may have more than one. The object of an fpdt:value triple is often a literal value or URI, but may also be a resource whose type is defined by Focal Point.

To summarize, in the natural representation of an element, if the datatype of an attribute is complex, then there is a single triple whose object is the complex datatype. Otherwise the datatype of the attribute is simple and there is one triple for each fpdt:value triple.

Usage of Literal Datatypes

Text is represented as plain text, not xsd:string, if it does not contain formatting markup, and as rdf:XMLLiteral if it does, in which case the markup should use XHTML. Integers are represented by xsd:integer. Decimal and floating point numbers are represented by xsd:decimal. Days of a calendar are represented by xsd:date and timestamps are represented by xsd:dateTime.

Focal Point Attribute Datatypes - Abstract Classes

The following classes are used to organize the set of Focal Point datatypes. They do not correspond to datatypes that an attribute may be assigned using the administrator user interface.

fpdt:Datatype

fpdt:Datatype is the class of all Focal Point datatypes.

fpdt:SimpleDatatype

fpdt:SimpleDatatype is a subclass of fpdt:Datatype. There may be zero or more fpdt:value triples in a simple datatype resource. In the natural representation of elements, each fpdt:value triple maps to a corresponding triple whose subject is the element, predicate is the URI associated with the attribute, and object is the object of the fpdt:value triple. fpdt:value therefore acts as a placeholder for the property URI associated with the attribute.

fpdt:ComplexDatatype

fpdt:ComplexDatatype is a subclass of fpdt:Datatype. It contains all complex datatypes. A complex datatype never contains fpdt:value properties. A complex datatype appears in both the natural and the generic graphs.

Identifying Parts of a Complex Datatype Using URI References

In general, a complex datatype is a resource that has many properties and contains other subordinate resources. We identify a complex datatype resource and its subordinate resources using URI references. These are URIs that include a fragment identifier. The base of the URI is the URI of the parent fps:Attribute resource whose rdf:value is the complex datatype resource. For example, a fpdt:Matrix resource is identified by a URI reference <#matrix> that is relative to the parent fps:Attribute resource URI.

Representing Containment Relations Using Multivalued Membership Properties on the Parent Resources

We represent the containment relation between resources using a multivalued property on the parent resource. For example, a fpdt:Matrix contains rows and columns. These containment relations are represented by fpdt:row and fpdt:column properties on the matrix. The rows and columns are identified by URI references like <#row-1> and <#column-A>. This design enables easy navigation from the parent to the child and facilitates interactive exploration and understanding of the structure of the resource.

Representing Order Using Sort Key Properties on the Children Resources

In some cases the order of the children is significant. There is often a natural property of the child resource that can serve as a sort key. For example, it is natural to sort fpdt:ChangeEvent resources by their dcterms:modified property. When no such natural sort key is provided, the order must be represented explicitly. Although it is possible to represent an ordered list using rdf:List and rdf:Seq, both of these techniques make SPARQL queries more difficult to write. We therefore introduce an explicit sequence number property, e.g. fpdt:rowNo, where a sort key is needed to represent the order. We also use fpdt:i as a generic sequence number, normally starting from 1. The use of sort key properties is SPARQL query friendly, and allows for more than one sort key where the need arises. For example, it is useful to sort fpdt:Cell resources by both fpdt:rowNo and fpdt:columnNo.

fpdt:Table

fpdt:Table is a complex datatype that represents a rectangular array of cells. Each cell is the intersection of a row and a column. The rows and columns of the table may have headings. See FPDatatypeExamplesMatrix for an example.

Tables are identified as URI references like <#matrix>, <#sheet-1>. Columns are identified like <#column-A>, <#column-1-A>. Rows are identified like <#row-1>, <#row-1-1>. Cells are identified like <#cell-A-1>, <#cell-1-A-1>. The content of

Tables use the following classes:

Table, row, column, and cell resources are identified using URI references that are based on the URI of their parent fps:Attribute resource. fpdt:Table is used as the base class for fpdt:Matrix and fpdt:Sheet. The rows, columns, and cells of a table are organized into a containment hierarchy. A table contains columns and rows. A row contains cells.

Tables use the following properties:

Focal Point Attribute Datatypes - Concrete Classes

The following classes are Focal Point datatypes that an attribute may be assigned via the administrator user interface. fpdt:History and fpdt:List have subclasses.

Focal Point supports the following datatypes as values of attributes:

Type	RDF Class	RDF SuperClass	Description
Check box	fpdt:CheckBox	fpdt:SimpleDatatype	A box that a member can select or clear to turn an option on or off.
Choice	fpdt:Choice	fpdt:SimpleDatatype	A list of predefined items that a member may select a single item from (e.g. status).
Date	fpdt:Date	fpdt:SimpleDatatype	A date value (for example 3/31/2010).
File	fpdt:File	fpdt:ComplexDatatype	A document, image or other file in the database, or a list of such files. Maximum total size is 50 MB.
Float	fpdt:Float	fpdt:SimpleDatatype	A real number that contains a fractional part (e.g. 3.14).
Heading	fpdt:Heading	fpdt:SimpleDatatype	An attribute consisting only of a title, used primarily for layout purposes.
History	fpdt:History	fpdt:ComplexDatatype	History can display attribute or element history for an element.
Incoming Links	fpdt:IncomingLinks	fpdt:SimpleDatatype	A list of elements that link to this element.
Integer	fpdt:Integer	fpdt:SimpleDatatype	A real number that contains no fractional part (e.g. 42).
Integration Link	fpdt:IntegrationLink	fpdt:SimpleDatatype	A list of link OSLC resources residing in a different repository.
Link	fpdt:Link	fpdt:SimpleDatatype	A link from one element to another. The target can be either in this workspace, or in another workspace.
List	fpdt:List	fpdt:ComplexDatatype	A list is a collection of either text attributes or link attributes.
Lock	fpdt:Lock	fdpt:SimpleDatatype	A selection of attributes that can be locked from editing. When the lock attribute is activated for an element the attributes selected in the lock attribute cannot be edited and the element cannot be deleted.
Matrix	fpdt:Matrix	fpdt:Table	A matrix attribute consists of several text, float or integer attributes in a grid.
Mirror	fpdt:Mirror	fpdt:Datatype	A mirrored value of another attribute in another element.
Multichoice	fpdt:MultiChoice	fpdt:SimpleDatatype	A list of predefined items that a member may select multiple items from.
Text	fpdt:Text	fpdt:SimpleDatatype	A text field where a member enters and edits text.
Time Grid	fpdt:TimeGrid	fpdt:ComplexDatatype	Use this for calculations based on a time line.
URL	fpdt:Url	fpdt:SimpleDatatype	A link to a specific resource on the Internet (e.g. http://www.ibm.com).
Unique id	fpdt:UniqueId	fpdt:SimpleDatatype	A text field where the value must be unique. When new elements are created, the unique id attribute is automatically assigned a unique value.
Version	fpdt:Version	fpdt:SimpleDatatype	A number or character that automatically increases based on changes in other attributes.

fpdt:CheckBox

fpdt:CheckBox is a simple datatype.

fpdt:Choice

fpdt:Choice is a simple datatype.

fpdt:Date

fpdt:Date is a simple datatype.

fpdt:File

fpdt:File is a complex datatype that contains a list of zero or more file attachments. Each attachment has a title, content type, and content length. See FPDatatypeExamplesFile for an example.

A fpdt:File resource should be identified by a URI reference <#file> based on the URI of its parent fps:Attribute resource.

Files use the following class:

A fpdt:Attachment resource should be identified by a URI reference like <#attachment-1> based on the URI of its parent fps:Attribute resource.

Files use the following properties:

fpdt:Float

fpdt:Float is a simple datatype.

fpdt:Heading

fpdt:Heading is a simple datatype. It is a pseudo-attribute used for organizing other attributes. It has no primary value.

fpdt:History

fpdt:History is a complex datatype. It shows the change history of attribute values. Attributes must enable logging of changes in order for them to be included in a history attribute. The history attribute value may be either none, a graph, or a table. The table may contain a selected attribute or all the attributes of an element. These cases correspond to the following concrete subclasses of fpdt:History which is itself an abstract class:

fpdt:HistoryNone

fpdt:HistoryNone has no properties. This allows the user to turn off a history attribute without deleting it.

A fpdt:HistoryGraph resource should be identified by the URI reference <#historynone>. The URI reference is based on the URI of its parent fps:Attribute resource.

fpdt:HistoryGraph

fpdt:HistoryGraph is a graph that displays zero or more time series of numeric values. Each time series contains the historical values of an integer or float attribute, displayed as a line or bar graph, with on optional trend line. The graph is an image. The size of the image and the time range are controlled by the user. See FPDatatypeExamplesHistoryGraph for an example.

A fpdt:HistoryGraph resource should be identified by the URI reference <#historygraph>. The URI reference is based on the URI of its parent fps:Attribute resource.

fpdt:Size

ftdt:HistoryGraph uses the following enumerated resources:

fpdt:GraphTimeSeries

fpdt:GraphTimeSeries is a series of numeric attribute history values displayed in a graph, with an optional trend line.

Each fpdt:GraphTimeSeries should be identified by a URI reference <#series-1>, <#series-2>, etc. where the number is a the sequence number of the time series within the graph. The URI reference is based on the URI of its parent fps:Attribute resource.

ftdt:GraphTimeSeries uses the following enumerated resources:

fpdt:TrendLine

fpdt:TrendLine is a straight line that is fitted to the time series of historical values of an attribute.

Each fpdt:TrendLine should be identified by a URI reference <#trendline-1>, <#trendline-2>, etc. where the number corresponds to its fpdt:TimeSeries resource. The URI reference is based on the URI of its parent fps:Attribute resource.

fpdt:ChangeEvent

fpdt:ChangeEvent represents a single change of some attribute. For graphs, the change event contains the time of the event and the new value of the attribute.

Each fpdt:ChangeEvent should be identified by a URI reference <#event-1-1>, <#event-1-2>, etc. where the first number corresponds to its fpdt:TimeSeries resource and the second number is the sequence number of the event within the time series. The URI reference is based on the URI of its parent fps:Attribute resource.

fpdt:HistoryAttributeTable

fpdt:HistoryAttributeTable is a complex datatype that contains a series of change events for a given attribute. The attribute must enable change logging in order to appear in a fpdt:HistoryAttributeTable. See FPDatatypeExamplesHistoryAttributeTable for an example.

A fpdt:HistoryAttributeTable resource should be identified by the URI reference <#historyattributetable>. The URI reference is based on the URI of its parent fps:Attribute resource.

fpdt:ChangeEvent

Each fpdt:ChangeEvent should be identified by a URI reference <#event-1>, <#event-2>, etc. where the number is the sequence number of the event within the table, oldest first. The URI reference is based on the URI of its parent fps:Attribute resource.

fpdt:HistoryElementTable

fpdt:HistoryElementTable is a complex datatype that contains a series of change events for all the attributes of an element. Only the attributes that have enabled change logging will appear in a fpdt:HistoryElementTable.

A fpdt:HistoryElementTable resource should be identified by the URI reference <#historyelementtable>. The URI reference is based on the URI of its parent fps:Attribute resource.

Its structure is very similar to fpdt:HistoryAttributeTable. See FPDatatypeExamplesHistoryElementTable for an example.

fpdt:ChangeEvent

Each fpdt:ChangeEvent should be identified by a URI reference <#event-1>, <#event-2>, etc. where the number is the sequence number of the event within the table, newest first. The URI reference is based on the URI of its parent fps:Attribute resource.

fpdt:IncomingLinks

fpdt:IncomingLinks is a simple datatype. It is the set of incoming links from other elements. There may be zero or more incoming links.

fpdt:Integer

fpdt:Integer is a simple datatype.

fpdt:IntegrationLink

fpdt:IntegrationLink is a simple datatype. It is a link to another resource.

fpdt:Link

fpdt:Link is a simple datatype. It is a link to another element.

fpdt:List

fpdt:List is a base datatype. Lists may contain either text or links to other elements. These are represented by concrete subclasses.

fpdt:LinkList

fpdt:LinkList is a simple datatype. It is subclass of fpdt:List that contains a set of zero or more links to other elements. See FPDatatypeExamplesLinkList for an example.

fpdt:TextList

fpdt:TextList is a simple datatype. It is a subclass of fpdt:List that contains a set of zero or more entries. Each entry contain text, the timestamp of the entry, and the user who made the entry. See FPDatatypeExamplesTextList for an example.

Note that although fpdt:TextList is structurally similar to oslc:Discussion, their semantics are different since comments posted to a discussion are assumed to be immutable. In contrast, text list entries can be freely added, deleted, and modified.

fpdt:TextEntry

fpdt:TextEntry is a mutable text entry in an ordered list.

Each fpdt:TextEntry should be identified by a URI reference <#entry-1>, <#entry-2>, etc. where the number is the sequence number of the entry within the list. The URI reference is based on the URI of its parent fps:Attribute resource.

fpdt:Lock

fpdt:Lock is a simple datatype. When set to true it prevents deletion of the element or modification of a configured set of attributes.

fpdt:Matrix

fpdt:Matrix is a complex datatype. It is a subclass of fpdt:Table. See FPDatatypeExamplesMatrix for an example.

fpdt:Mirror

fpdt:Mirror inherits the datatype of the attribute that it mirrors.

fpdt:MultiChoice

fpdt:MultiChoice is a simple datatype.

fpdt:Text

fpdt:Text is a simple datatype.

fpdt:TimeGrid

TimeGrid is a complex datatype. See FPDatatypeExamplesTimeGrid for an example.

A timegrid has one or more sheets. Each sheet is a table in which the columns represent time periods.

Each sheet in a time grid has a name, start date, end date, time interval, and scenario type. The time interval and scenario type take values from an enumerated set of allowed values.

Each row of a time grid may be a summary, heading, locked, benefit, or cost, and may have a unit.

fpdt:TimeGrid uses the following classes:

fpdt:TimeGrid uses the following enumerated values:

fpdt:TimeGrid uses the following properties:

fpdt:Url

fpdt:Url is a simple datatype.

fpdt:UniqueId

fpdt:UniqueId is a simple datatype.

fpdt:Version

fpdt:Version is a simple datatype.

Examples

These examples are provided for purposes of illustration. We have tried to keep them consistent with the specification, but some inconsistencies may exist. In these cases, the specification is the authoritative source of information.

• fpdt:File
• fpdt:HistoryAttributeTable
• fpdt:HistoryElementTable
• fpdt:HistoryGraph
• fpdt:LinkList
• fpdt:Matrix
• fpdt:TextList