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Class Class

A Class represents a class term, also known as type in schema.org. A Class is identified by its IRI (e.g. schema:Thing), where, by convention, the class name itself starts with an uppercase letter. A Class instance is created with SDOAdapter.getClass() and offers the methods described below.

// following Class instance is used in the code examples below
const personClass = mySdoAdapter.getClass("schema:Person");
// it is also possible to create a Class instance with an absolute IRI or a label
const personClass2 = mySdoAdapter.getClass("https://schema.org/Person");
const personClass3 = mySdoAdapter.getClass("Person");

Hierarchy

Index

Properties

Methods

Properties

Protected Readonly IRI

IRI: string

Protected Readonly graph

graph: Graph

Methods

getDescription

  • getDescription(language?: string): null | string

  • Returns the description (rdfs:comment) of this Term. It is possible to pass a language tag as parameter to get the description in that language, as long as the vocabulary provides that language. The english ("en") language is understood as default.

    example
    const cwClass = mySdoAdapter.getClass("schema:CreativeWork");
    cwClass.getDescription();
    // returns the (english) description of the class schema:CreativeWork
    "The most generic kind of creative work, including books, movies, photographs, software programs, etc."

    Parameters

    • language: string = "en"

      the wished language for the description (default = "en")

    Returns null | string

    The description of this Term

getDescriptions

  • getDescriptions(): null | Record<string, string>

  • Returns all descriptions (rdfs:comment) of this Term as an Object. Each description (value) has a language tag (key) associated with it. Language tags are unique for each term (e.g. there is at most one description for any given language)

    example
    const tigerClass = mySdoAdapter.getClass("ex:Tiger");
    tigerClass.getDescriptions();
    // returns the descriptions of this class in all available languages:
    {
      "en": "The tiger (Panthera tigris) is the largest species among the Felidae and classified in the genus Panthera.",
      "zh": "虎（学名：Panthera tigris），俗称老虎、大虫，被人称为百獸之王，是現存体型最大的两种猫科动物之一（另一种是狮)"
    }

    Returns null | Record<string, string>

    The descriptions of this Term

getIRI

  • Retrieves the IRI of this Term in compact (e.g. schema:Friday) or in absolute form (e.g. https://schema.org/Friday). By default, the absolute form is returned

    example
    personClass.getIRI();
    // returns the absolute IRI of the "schema:Person" Class
    "https://schema.org/Person"

    nameProperty.getIRI("Compact");
    // returns the compact IRI of the "schema:name" Property
    "schema:name"

    Parameters

    • outputIRIType: OutputIRIType = "Absolute"

      states the format of the returned IRI, either "Compact" for the compact form, e.g. schema:Friday, or "Absolute" for the absolute form, e.g. https://schema.org/Friday

    Returns string

    The IRI of this Term

getName

  • getName(language?: string): null | string

  • Returns the name (rdfs:label) of this Term. It is possible to pass a language tag as parameter to get the name in that language, as long as the vocabulary provides that language. The english ("en") language is understood as default.

    example
    const hotelClass = mySdoAdapter.getClass("schema:Hotel");
    hotelClass.getName();
    // returns the (english) name of the class schema:Hotel
    "Hotel"

    Parameters

    • language: string = "en"

      the wished language for the name (default = "en")

    Returns null | string

    The name of this Term

getNames

  • getNames(): null | Record<string, string>

  • Returns all names (rdfs:label) of this Term as an Object. Each name (value) has a language tag (key) associated with it. Language tags are unique for each term (e.g. there is at most one name for any given language).

    example
    const tigerClass = mySdoAdapter.getClass("ex:Tiger");
    tigerClass.getNames();
    // returns the name of this class in all available languages:
    {
      "en": "Tiger",
      "de": "Tiger",
      "es": "Tigre",
      "zh": "虎"
    }

    Returns null | Record<string, string>

    The names (with language tag) of this Term

getProperties

  • Retrieves the properties of this Class

    example
    personClass.getProperties();
    // returns all properties of the class "schema:Person" (including inherited properties from its superclasses)
    [
       "schema:name",
       "schema:description",
       "schema:knows",
       "schema:worksFor",
       ...
    ]

    personClass.getProperties({ implicit: false });
    // returns only the explicit properties of the class "schema:Person"
    [
       "schema:address",
       "schema:weight",
       "schema:worksFor",
       ...
    ]

    Parameters

    • Optional paramObj: ParamObjIRIListInference

      an optional parameter object that filters and formats the result, and defines the inference behaviour: The "implicit"-parameter defaults to true and returns also implicit properties inherited from superclasses

    Returns string[]

    The properties of this Class

getSource

  • getSource(): null | string | string[]

  • This method was introduced mainly to return of source(s) for a term, as defined in the vocabulary itself with dcterms:source or schema:source. The later has been used to link to related github issues for the schema.org vocabulary.

    example
    const phoneticText = mySdoAdapter.getProperty("schema:phoneticText");
    phoneticText.getVocabulary();
    // returns source of the phoneticText property
    "https://github.com/schemaorg/schemaorg/issues/2108"

    Returns null | string | string[]

    The source IRI given by dcterms:source or schema:source of this Term

getSubClasses

  • Retrieves the subclasses of this Class

    example
    personClass.getSubClasses();
    // returns all subclasses of the class "schema:Person"
    [
       "schema:Patient"
    ]

    Parameters

    • Optional paramObj: ParamObjIRIListInference

      an optional parameter object that filters and formats the result, and defines the inference behaviour: The "implicit"-parameter defaults to true and returns also implicit subclasses inherited recursively from subclasses

    Returns string[]

    The subclasses of this Class

getSuperClasses

  • Retrieves the superclasses of this Class

    example
    personClass.getSuperClasses();
    // returns all superclasses of the class "schema:Person" (including inherited superclasses from its superclasses)
    [
       "schema:Thing"
    ]

    Parameters

    • Optional paramObj: ParamObjIRIListInference

      an optional parameter object that filters and formats the result, and defines the inference behaviour: The "implicit"-parameter defaults to true and returns also implicit superclasses inherited recursively from superclasses

    Returns string[]

    The superclasses of this Class

getTermTypeIRI

  • Retrieves the compact IRI for the type of this Term:

    Class -> "rdfs:Class"
    Property -> "rdf:Property"
    Enumeration -> "schema:Enumeration"
    EnumerationMember -> "soa:EnumerationMember"
    DataType -> "schema:DataType"

    example
    personClass.getTermTypeIRI();
    // returns the term type IRI of the "schema:Person" Class in compact form
    "rdfs:Class"

    nameProperty.getTermTypeIRI();
    // returns the term type IRI of the "schema:name" Property in compact form
    "rdf:Property"

    Returns TermTypeIRIValue

    The term-type-IRI of this Term

getTermTypeLabel

  • Retrieves the label (string) for the type of this Term:

    Class -> "Class"
    Property -> "Property"
    Enumeration -> "Enumeration"
    EnumerationMember -> "EnumerationMember"
    DataType -> "DataType"

    example
    personClass.getTermTypeLabel();
    // returns the term type label of the "schema:Person" Class
    "Class"

    nameProperty.getTermTypeLabel();
    // returns the term type label of the "schema:name" Property
    "Property"

    Returns TermTypeLabelValue

    The term-type-label of this Term

getVocabURLs

  • getVocabURLs(): null | string[]

  • Returns the URL of all vocabularies in which this term has been defined. Works only if the corresponding vocabulary was added through a URL, and not as a JSON-LD object.

    example
    // the parameter `schemaVersion: "12.0"` tells the SDO-Adapter instance to initialize with the schema.org vocabulary version 12.0
    const mySdoAdapter = await SOA.create({schemaVersion: "12.0"});

    const personClass = mySdoAdapter.getClass("schema:Person");
    personClass.getVocabURLs();
    // returns the source vocabulary url for this class - notice that this url points to version 12.0 of schema.org
    ["https://raw.githubusercontent.com/semantifyit/schemaorg/main/data/releases/12.0/schemaorg-all-https.jsonld"]

    Returns null | string[]

    The original vocabulary source urls of this Term

getVocabulary

  • getVocabulary(): string

  • This method was introduced mainly to return the vocabulary extension URL of schema.org to which the term belongs. The extension URL is defined in the vocabulary through the schema:isPartOf property. If no such property is given, then the namespace URL for this term is returned.

    example
    const personClass = mySdoAdapter.getClass("schema:Person");
    personClass.getVocabulary();
    // returns the vocabulary url for the person class, which is the core vocabulary of schema.org
    "https://schema.org"

    const patientClass = mySdoAdapter.getClass("schema:Patient");
    patientClass.getVocabulary();
    // returns the vocabulary url for the patient class, which is the health extension of schema.org
    "https://health-lifesci.schema.org"

    Returns string

    The vocabulary URL of this term (extension or namespace)

isRangeOf

  • Retrieves the properties that have this Class as a range

    example
    personClass.isRangeOf();
    // returns all properties for which the class "schema:Person" is a valid range
    [
       "schema:legislationPassedBy",
       "schema:sender",
       "schema:character",
       "schema:actors",
       ...
    ]

    Parameters

    • Optional paramObj: ParamObjIRIListInference

      an optional parameter object that filters and formats the result, and defines the inference behaviour: The "implicit"-parameter defaults to true and returns also implicit properties (where a superclass of this class is a range)

    Returns string[]

    The properties that have this Class as a range

isSupersededBy

  • Returns the IRI of the Term superseding this Term (defined with schema:supersededBy), if any. By default, the IRI is returned in compact form

    example
    const requirementsProperty = mySdoAdapter.getProperty("schema:requirements");
    requirementsProperty.isSupersededBy();
    // returns IRI for the term that supersedes the property schema:requirements in compact form
    "schema:softwareRequirements"

    requirementsProperty.isSupersededBy("Absolute");
    // returns IRI for the term that supersedes the property schema:requirements in absolute form
    "https://schema.org/softwareRequirements"

    Parameters

    • outputIRIType: OutputIRIType = "Compact"

      states the format of the returned IRI, either "Compact" for the compact form, e.g. schema:softwareRequirements, or "Absolute" for the absolute form, e.g. https://schema.org/softwareRequirements

    Returns null | string

    The Term superseding this Term, if any

isValidDomainOf

  • isValidDomainOf(propertyId: string, implicit?: boolean): boolean

  • Returns true, if the given property can use this class as a valid domain. The implicit parameter (default: true) allows to include properties inherited from superclasses

    example
    mediaObjectClass.isValidDomainOf("schema:dateline"); // true
    mediaObjectClass.isValidDomainOf("schema:name"); // true
    mediaObjectClass.isValidDomainOf("schema:name", true); // true
    mediaObjectClass.isValidDomainOf("schema:name", false); // false, since only direct domains are considered

    Parameters

    • propertyId: string

      The identification string of the property in question, can be an IRI (absolute or compact) or a label

    • implicit: boolean = true

      If true, include properties inherited from superclasses

    Returns boolean

    if this class is a valid domain for the given property

isValidRangeOf

  • isValidRangeOf(propertyId: string, implicit?: boolean): boolean

  • Returns true, if the given property can use this class as a valid range. The implicit parameter (default: true) allows to cover recursive relationships (e.g. subclasses of valid ranges are also taken into account)

    example
    mediaObjectClass.isValidRangeOf("schema:caption"); // true
    mediaObjectClass.isValidRangeOf("schema:license"); // true
    mediaObjectClass.isValidRangeOf("schema:license", true); // true
    mediaObjectClass.isValidRangeOf("schema:license", false); // false, since only direct ranges are considered

    Parameters

    • propertyId: string

      The identification string of the property in question, can be an IRI (absolute or compact) or a label

    • implicit: boolean = true

      If true, includes also subclasses of ranges

    Returns boolean

    if this class is a valid range for the given property

isValidSubClassOf

  • isValidSubClassOf(superClassId: string, implicit?: boolean): boolean

  • Returns true, if the given class is a valid superclass of this class. The implicit parameter (default: true) allows to cover recursive relationships (e.g. the superclass of a superclass is also taken into account)

    example
    hotelClass.isValidSubClassOf("schema:LodgingBusiness"); // true
    hotelClass.isValidSubClassOf("schema:Thing"); // true
    hotelClass.isValidSubClassOf("schema:Thing", true); // true
    hotelClass.isValidSubClassOf("schema:Thing", false); // false, since only direct superclasses are considered

    Parameters

    • superClassId: string

      The identification string of the superclass in question, can be an IRI (absolute or compact) or a label

    • implicit: boolean = true

      If true, includes also superclasses of superclasses

    Returns boolean

    if the other class is a valid superclass of this class

isValidSuperClassOf

  • isValidSuperClassOf(subClassId: string, implicit?: boolean): boolean

  • Returns true, if the given class is a valid subclass of this class. The implicit parameter (default: true) allows to cover recursive relationships (e.g. the subclass of a subclass is also taken into account)

    example
    thingClass.isValidSuperClassOf("schema:Place"); // true
    thingClass.isValidSuperClassOf("schema:Hotel"); // true
    thingClass.isValidSuperClassOf("schema:Hotel", true); // true
    thingClass.isValidSuperClassOf("schema:Hotel", false); // false, since only direct subclasses are considered

    Parameters

    • subClassId: string

      The identification string of the subclass in question, can be an IRI (absolute or compact) or a label

    • implicit: boolean = true

      If true, includes also subclasses of subclasses

    Returns boolean

    if the other class is a valid subclass of this class

toJSON

  • Generates a JSON representation of this Class (as JavaScript Object)

    example
    personClass.toJSON();
    // returns a JSON representing the class "schema:Person"
    {
     id: 'schema:Person',
     IRI: 'https://schema.org/Person',
     typeLabel: 'Class',
     typeIRI: 'rdfs:Class',
     vocabURLs: ['https://raw.githubusercontent.com/semantifyit/schemaorg/main/data/releases/13.0/schemaorg-all-https.jsonld'],
     vocabulary: 'https://schema.org',
     source: 'http://www.w3.org/wiki/WebSchemas/SchemaDotOrgSources#source_rNews',
     supersededBy: null,
     name: 'Person',
     description: 'A person (alive, dead, undead, or fictional).',
     superClasses: ['schema:Thing'],
     subClasses: ['schema:Patient'],
     properties: [
       'schema:contactPoint',
       'schema:jobTitle',
       'schema:colleagues',
       ...
     ],
     rangeOf: [
       'schema:legislationPassedBy',
       'schema:sender',
       'schema:character',
       ...
     ]
    }

    Parameters

    • Optional paramObj: ParamObjIRIListInference

      an optional parameter object that filters and formats the result, and defines the inference behaviour: The "implicit"-parameter defaults to true and returns also implicit data (e.g. recursive subclasses, superclasses, properties, etc.)

    Returns ToJsonClass

    The JSON representation of this Class as JavaScript Object

toString

  • Generates a JSON representation of this Class (as string)

    Check .toJSON() for an example output

    example
    personClass.toString();

    Parameters

    • Optional paramObj: ParamObjIRIListInference

      an optional parameter object that filters and formats the result, and defines the inference behaviour: The "implicit"-parameter defaults to true and returns also implicit data (e.g. recursive subclasses, superclasses, properties, etc.)

    Returns string

    The JSON representation of this Class as string