$Id: heml.xsd 2 2002-05-02 00:51:28Z brucerob $

$Date: 2002-05-01 21:51:28 -0300 (Wed, 01 May 2002) $

$Revision: 1.1 $

This is the XML Schema for Heml, version 20010702. See http://www.heml.org for more information on the project and for tools that transform documents that conform to this schema.

This schema's outer-most (or top-level) element is heml:Heml ; it represents a collection of historical events, each of which is encoded in an heml:Event element.

This schema has been built according to the following design pattern:

  1. Though .heml documents are produced by and for computational processes, they ought to be readable. Thus the element names border on the verbose.
  2. Types are given names ending with 'Type'
  3. Groups are given names ending with 'Group'
  4. Types and elements are capitalized; attributes begin with a lower-case letter.
  5. Every element that comprises other elements with non-editoral functions has these two optional editoral elements:
    1. A heml:Comment at the beginning of its content model (that is, before all other elements). This may comprise only plain text and is meant for editoral notes.
    2. A heml:Annex at the end of its content model (that is, after all other elements). This may comprise any markup; it is suited to adding application- or site-specific markup to the core of this Heml version.
  6. Elements whose names end with 'Set', such as 'LabelSet', represent a collection of elements which refer to the same object or idea but differ only in language. These should be distinguished from elements whose name are in the plural; the latter, such as the 'Events' element collect element that refer to different things or ideas.

 Editorial text which may be added as the first sub-element of a sequence. An optional element comprising mixed content; used to add non-standard or experimental markup to Heml elements. Where it appears, it is the last element in a sequence. The topl-level, or root, element in a Heml document. Comprises a Head element (metadata) and a Body element, which itself is a group of Event elements. A container for metadata. Currently, this is mixed-content, but when Dublin Core Metadata namespaces and schemas are finalized this element will conform to those specifications. A collection of heml:Event s. The heml:Event element represents what is known about an historical event. It comprises, in order, Labels, Date, Location, Participants and References elements. See their documentation for further information. An element comprising a text string and an xml:lang attribute. *********** * End 'Chronology' element and related materials * * * Begin 'Label' element and related materials * Gathers labels constrained so as to not allow multiple labels of the same xml:lang declaration. Gathers labels constrained so as to not allow multiple labels of the same xml:lang declaration. Applies an id attribute to the collecting element, which whose name usually ends in 'Set'. ************ End LABELS element and related materials. Begin CLASSIFICATION element and related materials Gathers means of classifying the event. Currently, only the KeywordClassificationSet element, or reference using the KeywordClassificationSetRef element, are possible. A collection of heml:Label elements that refer, each in their own language, to a keyword or concept under which this event should be classified. Once written, should be referred to with a KeywordClassificationRef element. Refers to a KeywordClassificationSet element. ************ End CLASSIFICATION and related materials. Begin CHRONOLOGY element and related materials Represents the information known about the date of an event. Can comprise an AbsoluteDate, ComplexDate or DateRange element. Represents the date of an event as a single calendrical value in a common format, such as XML Schema's gYear datatype which would be wrapped in a heml:XMLSchemaGYear element. Internally, an AbsoluteDateType resolves to a single 'time' values: the first possible chronon which the encoding might represent. A 'chronon' is the smallest unit of time used by a computational agent. In the code provided by heml.org, written in Java, this is the millisecond. SimpleDates thus differ from DateRanges, which are represented internally by two values. A choice among the date data types supported by Heml. Represents a span of time. Internally, a DateRange resolves to two 'time' values. A date represented in XML Schema's date datatype. Note that a '-' may be used before the date to indicate a year BCE. A date represented as a year alone, in XML Schema's gYear datatype. Note that a '-' may be used before the value to indicate a year BCE. Represents a date expressed through a relation with another date. For instance, two events dated to 264 BC one of which we know took place after the other but for whom no further chronological information is available. The second of these should be given a ComplexDate element comprising the SimpleDate of 264 BC (perhaps with a XMLSchemaGYear element containing the value -264) and the ChronologicalRelationship element which refers to the first event and has a type attribute of 'after'. In a ComplexDate, expresses the relationship between current date and the one to which it is related. The only 'relationship' element now allowed is 'tpq', meaning that the referred-to date is this date's terminus post quem. That is, this date takes place after the referred-to date. * * Begin 'Location' element and related materials * The geographical location of the event. Currently only encodes points in lat/long and gives label. xml:lang-encoded set of string elements that internationally label this Location. A reference to an existing Location element. Gathers together the constrains for hours/minutes/seconds appropriate for a point of latitude. Limited to values of -90 to 90, representing the possible values of latitude south and north respectively. Gathers together the constrains for hours/minutes/seconds appropriate for a point of longitude. Limited to values of -180 to 180, representing the possible values of longitude east and west respectively. A positive integer with a maximum inclusive value of 59. Used for minutes and seconds. ****** End LOCATION element. Begin PARTICIPANTS and related elements. heml:Participants comprises records and references that list the people who were involved in the event. (Should add coporate groups as well.) Groups PersonWithRole and plain old Person elements. A XML IDREF to a heml:Person defined elsewhere in this document. A type that defines a person. Each person should be defined only once per heml document, and subsequent references should be made with the heml:PersonRef element. Joins a Person or PersonRef with a RoleLabelSet or RoleLabelSetRef. A collection of heml:Name, that is language-specific instances, all of which refer to the same name and person. The containing Name element as represented a certain language. The xml:lang attribute encodes the language according to ISO 639-1 . The part of a name that should be the primary key in sorting display. For instance: 'Robertson' in the Canadian name 'Bruce Gordon Robertson' or 'Julius' in 'Gaius Julius Caesar'. When used for names of coporate groups, not personal names, it should be used alone. The part of a name that should be the secondary key in sorting and display. For instance: 'Bruce' in the Canadian name 'Bruce Gordon Robertson' or 'Caesar' in 'Gaius Julius Caesar'. The part of a name that should be the tertiary key in sorting and display. For instance: 'Gordon' in the Canadian name 'Bruce Gordon Robertson' or 'Gaius' in 'Gaius Julius Caesar'. ******* End PARTICIPANTS and related elements. Begin REFERENCES. Provides a simple hyperlink to a resource. The xml:lang attribute records the language of the resource in ISO 639-1 (two character) format. For one common document, gathers sources which are accessed by network, probably through the http. Distinguished from PhysicalSources , which include printed books. For one common document, gathers sources that are available in a physical medium, such as printed books. Comprises all the means of defining a physical source. Currently, only docbook's bibliomixed element is allowed, but it is intended that other, more rich markup such as the TEI will be added when they are provided in XML Schema.

An Originator is a person (or, presumably, corporation of people) who provides the referred to information. For instance, a holocaust-survivor interviewed in a video medium is not the author of the account she gives (this information would be provided in the NetworkedSources or PhysicalSources elements), but she is clearly the person with whom the historian is most interested. Accordingly Heml encourages the compiler to add as much information about the Originator as possible, including element that record sex, lifespan, etc.

 ****** * End 'References' and related elements * * Begin Utility elements