rdfaparser.js

//  RDFa Parser for rdflib.js

// Originally by: Alex Milowski
// From https://github.com/alexmilowski/green-turtle
// Converted: timbl 2015-08-25 not yet working
// Added wrapper: csarven 2016-05-09 working

// RDFaProcessor.prototype = new Object() // Was URIResolver

// RDFaProcessor.prototype.constructor=RDFaProcessor

// options.base = base URI    not really an option, shopuld always be set.
//

import BlankNode from './blank-node'
import Literal from './literal'
import NamedNode from './named-node'
import * as Uri from './uri'
import * as Util from './utils-js'
import rdf from './factories/canonical-data-factory'

if (typeof Node === 'undefined') { //  @@@@@@ Global. Interface to xmldom.
  var Node = {
    ELEMENT_NODE: 1,
    ATTRIBUTE_NODE: 2,
    TEXT_NODE: 3,
    CDATA_SECTION_NODE: 4,
    ENTITY_REFERENCE_NODE: 5,
    ENTITY_NODE: 6,
    PROCESSING_INSTRUCTION_NODE: 7,
    COMMENT_NODE: 8,
    DOCUMENT_NODE: 9,
    DOCUMENT_TYPE_NODE: 10,
    DOCUMENT_FRAGMENT_NODE: 11,
    NOTATION_NODE: 12
  }
}

export default class RDFaProcessor {
  constructor (kb, options) {
    this.options = options || {}
    this.kb = kb
    this.target = options.target || {
      graph: {
        subjects: {},
        prefixes: {},
        terms: {}
      }
    }
    // XXX: Added to track bnodes
    this.blankNodes = []
    // XXX: Added for normalisation
    this.htmlOptions = {
      'selfClosing': 'br img input area base basefont col colgroup source wbr isindex link meta param hr'
    }
    this.theOne = '_:' + (new Date()).getTime()
    this.language = null
    this.vocabulary = null
    this.blankCounter = 0
    this.langAttributes = [ { namespaceURI: 'http://www.w3.org/XML/1998/namespace', localName: 'lang' } ]
    this.inXHTMLMode = false
    this.absURIRE = /[\w\_\-]+:\S+/
    this.finishedHandlers = []
    this.init()
  }

  addTriple (origin, subject, predicate, object) {
    var su, ob, pr, or
    if (typeof subject === 'undefined') {
      su = rdf.namedNode(this.options.base)
    } else {
      su = this.toRDFNodeObject(subject)
    }
    pr = this.toRDFNodeObject(predicate)
    ob = this.toRDFNodeObject(object)
    or = rdf.namedNode(this.options.base)
    // console.log('Adding { ' + su + ' ' + pr + ' ' + ob + ' ' + or + ' }')
    this.kb.add(su, pr, ob, or)
  }

  ancestorPath (node) {
    var path = ''
    while (node && node.nodeType !== Node.DOCUMENT_NODE) {
      path = '/' + node.localName + path
      node = node.parentNode
    }
    return path
  }

  copyMappings (mappings) {
    var newMappings = {}
    for (var k in mappings) {
      newMappings[k] = mappings[k]
    }
    return newMappings
  }

  copyProperties () {
  }

  deriveDateTimeType (value) {
    for (var i = 0; i < RDFaProcessor.dateTimeTypes.length; i++) {
      // console.log("Checking "+value+" against "+RDFaProcessor.dateTimeTypes[i].type)
      var matched = RDFaProcessor.dateTimeTypes[i].pattern.exec(value)
      if (matched && matched[0].length === value.length) {
        // console.log("Matched!")
        return RDFaProcessor.dateTimeTypes[i].type
      }
    }
    return null
  }

  init () {
  }

  newBlankNode () {
    this.blankCounter++
    return '_:' + this.blankCounter
  }

  newSubjectOrigin (origin, subject) {
  }

  parseCURIE (value, prefixes, base) {
    var colon = value.indexOf(':')
    var uri
    if (colon >= 0) {
      var prefix = value.substring(0, colon)
      if (prefix === '') {
        // default prefix
        uri = prefixes['']
        return uri ? uri + value.substring(colon + 1) : null
      } else if (prefix === '_') {
        // blank node
        return '_:' + value.substring(colon + 1)
      } else if (RDFaProcessor.NCNAME.test(prefix)) {
        uri = prefixes[prefix]
        if (uri) {
          return uri + value.substring(colon + 1)
        }
      }
    }
    return null
  }

  parseCURIEOrURI (value, prefixes, base) {
    var curie = this.parseCURIE(value, prefixes, base)
    if (curie) {
      return curie
    }
    return this.resolveAndNormalize(base, value)
  }

  parsePredicate (value, defaultVocabulary, terms, prefixes, base,
                  ignoreTerms) {
    if (value === '') {
      return null
    }
    var predicate = this.parseTermOrCURIEOrAbsURI(value, defaultVocabulary, ignoreTerms ? null : terms, prefixes, base)
    if (predicate && predicate.indexOf('_:') === 0) {
      return null
    }
    return predicate
  }

  parsePrefixMappings (str, target) {
    var values = this.tokenize(str)
    var prefix = null
    // var uri = null
    for (var i = 0; i < values.length; i++) {
      if (values[i][values[i].length - 1] === ':') {
        prefix = values[i].substring(0, values[i].length - 1)
      } else if (prefix) {
        target[prefix] = this.options.base ? Uri.join(values[i], this.options.base) : values[i]
        prefix = null
      }
    }
  }

  static parseRDFaDOM (dom, kb, base) {
    var p = new RDFaProcessor(kb, { 'base': base })
    //  Cannot assign to read only property 'baseURI' of object '#<XMLDocument>':
    if (!dom.baseURI) { // Note this became a read-only attribute some time before 2018
      dom.baseURI = base // oinly set if not already set
    }
    p.process(dom, { baseURI: base})
  }

  parseSafeCURIEOrCURIEOrURI (value, prefixes, base) {
    value = this.trim(value)
    if (value.charAt(0) === '[' && value.charAt(value.length - 1) === ']') {
      value = value.substring(1, value.length - 1)
      value = value.trim(value)
      if (value.length === 0) {
        return null
      }
      if (value === '_:') {
        // the one node
        return this.theOne
      }
      return this.parseCURIE(value, prefixes, base)
    } else {
      return this.parseCURIEOrURI(value, prefixes, base)
    }
  }

  parseTermOrCURIEOrAbsURI (value, defaultVocabulary, terms, prefixes, base) {
    // alert("Parsing "+value+" with default vocab "+defaultVocabulary)
    value = this.trim(value)
    var curie = this.parseCURIE(value, prefixes, base)
    if (curie) {
      return curie
    } else if (terms) {
      if (defaultVocabulary && !this.absURIRE.exec(value)) {
        return defaultVocabulary + value
      }
      var term = terms[value]
      if (term) {
        return term
      }
      var lcvalue = value.toLowerCase()
      term = terms[lcvalue]
      if (term) {
        return term
      }
    }
    if (this.absURIRE.exec(value)) {
      return this.resolveAndNormalize(base, value)
    }
    return null
  }

  parseTermOrCURIEOrURI (value, defaultVocabulary, terms, prefixes, base) {
    // alert("Parsing "+value+" with default vocab "+defaultVocabulary)
    value = this.trim(value)
    var curie = this.parseCURIE(value, prefixes, base)
    if (curie) {
      return curie
    } else {
      var term = terms[value]
      if (term) {
        return term
      }
      var lcvalue = value.toLowerCase()
      term = terms[lcvalue]
      if (term) {
        return term
      }
      if (defaultVocabulary && !this.absURIRE.exec(value)) {
        return defaultVocabulary + value
      }
    }
    return this.resolveAndNormalize(base, value)
  }

  parseURI (uri) {
    return uri // We just use strings as URIs, not objects now.
  }

  process (node, options) {
    /*
    if (!window.console) {
       window.console = { log: function() {} }
    } */
    options = options || {}
    var base
    if (node.nodeType === Node.DOCUMENT_NODE) {
      if (node.baseURI && !options.baseURI) {
        options.baseURI = node.baseURI  // be defensive as DOM implementations vary
      }
      base = node.baseURI
      node = node.documentElement
      if (!node.baseURI) {
        node.baseURI = base
      }
      this.setContext(node)
    } else if (node.parentNode.nodeType === Node.DOCUMENT_NODE) {
      this.setContext(node)
    }
    var queue = []
    // Fix for Firefox that includes the hash in the base URI
    var removeHash = function (baseURI) {
      // Fix for undefined baseURI property
      if (!baseURI && options && options.baseURI) {
        return options.baseURI
      }

      var hash = baseURI.indexOf('#')
      if (hash >= 0) {
        baseURI = baseURI.substring(0, hash)
      }
      if (options && options.baseURIMap) {
        baseURI = options.baseURIMap(baseURI)
      }
      return baseURI
    }
    queue.push({ current: node,
      context: this.push(null, removeHash(node.baseURI))
    })
    while (queue.length > 0) {
      var item = queue.shift()
      if (item.parent) {
        // Sequence Step 14: list triple generation
        if (item.context.parent && item.context.parent.listMapping === item.listMapping) {
          // Skip a child context with exactly the same mapping
          continue
        }
        // console.log("Generating lists for "+item.subject+", tag "+item.parent.localName)
        for (let predicate in item.listMapping) {
          var list = item.listMapping[predicate]
          if (list.length === 0) {
            this.addTriple(item.parent, item.subject, predicate, { type: RDFaProcessor.objectURI, value: 'http://www.w3.org/1999/02/22-rdf-syntax-ns#nil' })
            continue
          }
          var bnodes = []
          for (let i = 0; i < list.length; i++) {
            bnodes.push(this.newBlankNode())
          // this.newSubject(item.parent,bnodes[i])
          }
          for (let i = 0; i < bnodes.length; i++) {
            this.addTriple(item.parent, bnodes[i], 'http://www.w3.org/1999/02/22-rdf-syntax-ns#first', list[i])
            this.addTriple(item.parent, bnodes[i], 'http://www.w3.org/1999/02/22-rdf-syntax-ns#rest', { type: RDFaProcessor.objectURI, value: (i + 1) < bnodes.length ? bnodes[i + 1] : 'http://www.w3.org/1999/02/22-rdf-syntax-ns#nil' })
          }
          this.addTriple(item.parent, item.subject, predicate, { type: RDFaProcessor.objectURI, value: bnodes[0] })
        }
        continue
      }
      var current = item.current
      var context = item.context
      // console.log("Tag: "+current.localName+", listMapping="+JSON.stringify(context.listMapping))
      // Sequence Step 1
      var skip = false
      var newSubject = null
      var currentObjectResource = null
      var typedResource = null
      var prefixes = context.prefixes
      var prefixesCopied = false
      var incomplete = []
      var listMapping = context.listMapping
      var listMappingDifferent = !context.parent
      var language = context.language
      var vocabulary = context.vocabulary
      // TODO: the "base" element may be used for HTML+RDFa 1.1
      base = this.parseURI(removeHash(current.baseURI))
      current.item = null
      // Sequence Step 2: set the default vocabulary
      var vocabAtt = current.getAttributeNode('vocab')
      if (vocabAtt) {
        let value = this.trim(vocabAtt.value)
        if (value.length > 0) {
          vocabulary = value
          var baseSubject = base.spec
          // this.newSubject(current,baseSubject)
          this.addTriple(current, baseSubject, 'http://www.w3.org/ns/rdfa#usesVocabulary', { type: RDFaProcessor.objectURI, value: vocabulary })
        } else {
          vocabulary = this.vocabulary
        }
      }
      // Sequence Step 3: IRI mappings
      // handle xmlns attributes
      for (var i = 0; i < current.attributes.length; i++) {
        var att = current.attributes[i]
        // if (att.namespaceURI=="http://www.w3.org/2000/xmlns/") {
        if (att.nodeName.charAt(0) === 'x' && att.nodeName.indexOf('xmlns:') === 0) {
          if (!prefixesCopied) {
            prefixes = this.copyMappings(prefixes)
            prefixesCopied = true
          }
          var prefix = att.nodeName.substring(6)
          // TODO: resolve relative?
          var ref = RDFaProcessor.trim(att.value)
          prefixes[prefix] = this.options.base ? Uri.join(ref, this.options.base) : ref
        }
      }
      // Handle prefix mappings (@prefix)
      var prefixAtt = current.getAttributeNode('prefix')
      if (prefixAtt) {
        if (!prefixesCopied) {
          prefixes = this.copyMappings(prefixes)
          prefixesCopied = true
        }
        this.parsePrefixMappings(prefixAtt.value, prefixes)
      }
      // Sequence Step 4: language
      var xmlLangAtt = null
      for (let i = 0; !xmlLangAtt && i < this.langAttributes.length; i++) {
        xmlLangAtt = current.getAttributeNodeNS(this.langAttributes[i].namespaceURI, this.langAttributes[i].localName)
      }
      if (xmlLangAtt) {
        let value = RDFaProcessor.trim(xmlLangAtt.value)
        if (value.length > 0) {
          language = value
        } else {
          language = null
        }
      }
      var relAtt = current.getAttributeNode('rel')
      var revAtt = current.getAttributeNode('rev')
      var typeofAtt = current.getAttributeNode('typeof')
      var propertyAtt = current.getAttributeNode('property')
      var datatypeAtt = current.getAttributeNode('datatype')
      var datetimeAtt = this.inHTMLMode
        ? current.getAttributeNode('datetime')
        : null
      var contentAtt = current.getAttributeNode('content')
      var aboutAtt = current.getAttributeNode('about')
      var srcAtt = current.getAttributeNode('src')
      var resourceAtt = current.getAttributeNode('resource')
      var hrefAtt = current.getAttributeNode('href')
      var inlistAtt = current.getAttributeNode('inlist')
      var relAttPredicates = []
      var predicate, values
      if (relAtt) {
        values = this.tokenize(relAtt.value)
        for (let i = 0; i < values.length; i++) {
          predicate = this.parsePredicate(values[i], vocabulary, context.terms, prefixes, base, this.inHTMLMode && propertyAtt !== null)
          if (predicate) {
            relAttPredicates.push(predicate)
          }
        }
      }
      var revAttPredicates = []
      if (revAtt) {
        values = this.tokenize(revAtt.value)
        for (let i = 0; i < values.length; i++) {
          predicate = this.parsePredicate(values[i], vocabulary, context.terms, prefixes, base, this.inHTMLMode && propertyAtt)
          if (predicate) {
            revAttPredicates.push(predicate)
          }
        }
      }
      // Section 3.1, bullet 7
      if (this.inHTMLMode && (relAtt || revAtt) && propertyAtt) {
        if (relAttPredicates.length === 0) {
          relAtt = null
        }
        if (revAttPredicates.length === 0) {
          revAtt = null
        }
      }
      if (relAtt || revAtt) {
        // Sequence Step 6: establish new subject and value
        if (aboutAtt) {
          newSubject = this.parseSafeCURIEOrCURIEOrURI(aboutAtt.value, prefixes, base)
        }
        if (typeofAtt) {
          typedResource = newSubject
        }
        if (!newSubject) {
          if (current.parentNode.nodeType === Node.DOCUMENT_NODE) {
            newSubject = removeHash(current.baseURI)
          } else if (context.parentObject) {
            // TODO: Verify: If the xml:base has been set and the parentObject is the baseURI of the parent, then the subject needs to be the new base URI
            newSubject = removeHash(current.parentNode.baseURI) === context.parentObject ? removeHash(current.baseURI) : context.parentObject
          }
        }
        if (resourceAtt) {
          currentObjectResource = this.parseSafeCURIEOrCURIEOrURI(resourceAtt.value, prefixes, base)
        }
        if (!currentObjectResource) {
          if (hrefAtt) {
            currentObjectResource = this.resolveAndNormalize(base, encodeURI(hrefAtt.value))
          } else if (srcAtt) {
            currentObjectResource = this.resolveAndNormalize(base, encodeURI(srcAtt.value))
          } else if (typeofAtt && !aboutAtt && !(this.inXHTMLMode && (current.localName === 'head' || current.localName === 'body'))) {
            currentObjectResource = this.newBlankNode()
          }
        }
        if (typeofAtt && !aboutAtt && this.inXHTMLMode && (current.localName === 'head' || current.localName === 'body')) {
          typedResource = newSubject
        } else if (typeofAtt && !aboutAtt) {
          typedResource = currentObjectResource
        }
      } else if (propertyAtt && !contentAtt && !datatypeAtt) {
        // Sequence Step 5.1: establish a new subject
        if (aboutAtt) {
          newSubject = this.parseSafeCURIEOrCURIEOrURI(aboutAtt.value, prefixes, base)
          if (typeofAtt) {
            typedResource = newSubject
          }
        }
        if (!newSubject && current.parentNode.nodeType === Node.DOCUMENT_NODE) {
          newSubject = removeHash(current.baseURI)
          if (typeofAtt) {
            typedResource = newSubject
          }
        } else if (!newSubject && context.parentObject) {
          // TODO: Verify: If the xml:base has been set and the parentObject is the baseURI of the parent, then the subject needs to be the new base URI
          newSubject = removeHash(current.parentNode.baseURI) === context.parentObject ? removeHash(current.baseURI) : context.parentObject
        }
        if (typeofAtt && !typedResource) {
          if (resourceAtt) {
            typedResource = this.parseSafeCURIEOrCURIEOrURI(resourceAtt.value, prefixes, base)
          }
          if (!typedResource && hrefAtt) {
            typedResource = this.resolveAndNormalize(base, encodeURI(hrefAtt.value))
          }
          if (!typedResource && srcAtt) {
            typedResource = this.resolveAndNormalize(base, encodeURI(srcAtt.value))
          }
          if (!typedResource && (this.inXHTMLMode || this.inHTMLMode) && (current.localName === 'head' || current.localName === 'body')) {
            typedResource = newSubject
          }
          if (!typedResource) {
            typedResource = this.newBlankNode()
          }
          currentObjectResource = typedResource
        }
      // console.log(current.localName+", newSubject="+newSubject+", typedResource="+typedResource+", currentObjectResource="+currentObjectResource)
      } else {
        // Sequence Step 5.2: establish a new subject
        if (aboutAtt) {
          newSubject = this.parseSafeCURIEOrCURIEOrURI(aboutAtt.value, prefixes, base)
        }
        if (!newSubject && resourceAtt) {
          newSubject = this.parseSafeCURIEOrCURIEOrURI(resourceAtt.value, prefixes, base)
        }
        if (!newSubject && hrefAtt) {
          newSubject = this.resolveAndNormalize(base, encodeURI(hrefAtt.value))
        }
        if (!newSubject && srcAtt) {
          newSubject = this.resolveAndNormalize(base, encodeURI(srcAtt.value))
        }
        if (!newSubject) {
          if (current.parentNode.nodeType === Node.DOCUMENT_NODE) {
            newSubject = removeHash(current.baseURI)
          } else if ((this.inXHTMLMode || this.inHTMLMode) && (current.localName === 'head' || current.localName === 'body')) {
            newSubject = removeHash(current.parentNode.baseURI) === context.parentObject ? removeHash(current.baseURI) : context.parentObject
          } else if (typeofAtt) {
            newSubject = this.newBlankNode()
          } else if (context.parentObject) {
            // TODO: Verify: If the xml:base has been set and the parentObject is the baseURI of the parent, then the subject needs to be the new base URI
            newSubject = removeHash(current.parentNode.baseURI) === context.parentObject ? removeHash(current.baseURI) : context.parentObject
            if (!propertyAtt) {
              skip = true
            }
          }
        }
        if (typeofAtt) {
          typedResource = newSubject
        }
      }
      // console.log(current.tagName+": newSubject="+newSubject+", currentObjectResource="+currentObjectResource+", typedResource="+typedResource+", skip="+skip)
      // var rdfaData = null
      if (newSubject) {
        // this.newSubject(current,newSubject)
        if (aboutAtt || resourceAtt || typedResource) {
          var id = newSubject
          if (typeofAtt && !aboutAtt && !resourceAtt && currentObjectResource) {
            id = currentObjectResource
          }
          // console.log("Setting data attribute for "+current.localName+" for subject "+id)
          this.newSubjectOrigin(current, id)
        }
      }
      // Sequence Step 7: generate type triple
      if (typedResource) {
        values = this.tokenize(typeofAtt.value)
        for (let i = 0; i < values.length; i++) {
          var object = this.parseTermOrCURIEOrAbsURI(values[i], vocabulary, context.terms, prefixes, base)
          if (object) {
            this.addTriple(current, typedResource, RDFaProcessor.typeURI, { type: RDFaProcessor.objectURI, value: object })
          }
        }
      }
      // Sequence Step 8: new list mappings if there is a new subject
      // console.log("Step 8: newSubject="+newSubject+", context.parentObject="+context.parentObject)
      if (newSubject && newSubject !== context.parentObject) {
        // console.log("Generating new list mapping for "+newSubject)
        listMapping = {}
        listMappingDifferent = true
      }
      // Sequence Step 9: generate object triple
      if (currentObjectResource) {
        if (relAtt && inlistAtt) {
          for (let i = 0; i < relAttPredicates.length; i++) {
            let list = listMapping[relAttPredicates[i]]
            if (!list) {
              list = []
              listMapping[relAttPredicates[i]] = list
            }
            list.push({ type: RDFaProcessor.objectURI, value: currentObjectResource })
          }
        } else if (relAtt) {
          for (let i = 0; i < relAttPredicates.length; i++) {
            this.addTriple(current, newSubject, relAttPredicates[i], { type: RDFaProcessor.objectURI, value: currentObjectResource })
          }
        }
        if (revAtt) {
          for (let i = 0; i < revAttPredicates.length; i++) {
            this.addTriple(current, currentObjectResource, revAttPredicates[i], { type: RDFaProcessor.objectURI, value: newSubject })
          }
        }
      } else {
        // Sequence Step 10: incomplete triples
        if (newSubject && !currentObjectResource && (relAtt || revAtt)) {
          currentObjectResource = this.newBlankNode()
        // alert(current.tagName+": generated blank node, newSubject="+newSubject+" currentObjectResource="+currentObjectResource)
        }
        if (relAtt && inlistAtt) {
          for (let i = 0; i < relAttPredicates.length; i++) {
            let list = listMapping[relAttPredicates[i]]
            if (!list) {
              list = []
              listMapping[predicate] = list
            }
            // console.log("Adding incomplete list for "+predicate)
            incomplete.push({ predicate: relAttPredicates[i], list: list })
          }
        } else if (relAtt) {
          for (let i = 0; i < relAttPredicates.length; i++) {
            incomplete.push({ predicate: relAttPredicates[i], forward: true })
          }
        }
        if (revAtt) {
          for (let i = 0; i < revAttPredicates.length; i++) {
            incomplete.push({ predicate: revAttPredicates[i], forward: false })
          }
        }
      }
      // Step 11: Current property values
      if (propertyAtt) {
        var datatype = null
        var content = null
        if (datatypeAtt) {
          datatype = datatypeAtt.value === '' ? RDFaProcessor.PlainLiteralURI : this.parseTermOrCURIEOrAbsURI(datatypeAtt.value, vocabulary, context.terms, prefixes, base)
          if (datetimeAtt && !contentAtt) {
            content = datetimeAtt.value
          } else {
            content = datatype === RDFaProcessor.XMLLiteralURI || datatype === RDFaProcessor.HTMLLiteralURI ? null : (contentAtt ? contentAtt.value : current.textContent)
          }
        } else if (contentAtt) {
          datatype = RDFaProcessor.PlainLiteralURI
          content = contentAtt.value
        } else if (datetimeAtt) {
          content = datetimeAtt.value
          datatype = RDFaProcessor.deriveDateTimeType(content)
          if (!datatype) {
            datatype = RDFaProcessor.PlainLiteralURI
          }
        } else if (!relAtt && !revAtt) {
          if (resourceAtt) {
            content = this.parseSafeCURIEOrCURIEOrURI(resourceAtt.value, prefixes, base)
          }
          if (!content && hrefAtt) {
            content = this.resolveAndNormalize(base, encodeURI(hrefAtt.value))
          } else if (!content && srcAtt) {
            content = this.resolveAndNormalize(base, encodeURI(srcAtt.value))
          }
          if (content) {
            datatype = RDFaProcessor.objectURI
          }
        }
        if (!datatype) {
          if (typeofAtt && !aboutAtt) {
            datatype = RDFaProcessor.objectURI
            content = typedResource
          } else {
            content = current.textContent
            if (this.inHTMLMode && current.localName === 'time') {
              datatype = RDFaProcessor.deriveDateTimeType(content)
            }
            if (!datatype) {
              datatype = RDFaProcessor.PlainLiteralURI
            }
          }
        }
        values = this.tokenize(propertyAtt.value)
        for (let i = 0; i < values.length; i++) {
          let predicate = this.parsePredicate(values[i], vocabulary, context.terms, prefixes, base)
          if (predicate) {
            if (inlistAtt) {
              let list = listMapping[predicate]
              if (!list) {
                list = []
                listMapping[predicate] = list
              }
              list.push((datatype === RDFaProcessor.XMLLiteralURI || datatype === RDFaProcessor.HTMLLiteralURI) ? { type: datatype, value: current.childNodes } : { type: datatype || RDFaProcessor.PlainLiteralURI, value: content, language: language })
            } else {
              if (datatype === RDFaProcessor.XMLLiteralURI || datatype === RDFaProcessor.HTMLLiteralURI) {
                this.addTriple(current, newSubject, predicate, { type: datatype, value: current.childNodes })
              } else {
                this.addTriple(current, newSubject, predicate, { type: datatype || RDFaProcessor.PlainLiteralURI, value: content, language: language })
              // console.log(newSubject+" "+predicate+"="+content)
              }
            }
          }
        }
      }
      // Sequence Step 12: complete incomplete triples with new subject
      if (newSubject && !skip) {
        for (let i = 0; i < context.incomplete.length; i++) {
          if (context.incomplete[i].list) {
            // console.log("Adding subject "+newSubject+" to list for "+context.incomplete[i].predicate)
            // TODO: it is unclear what to do here
            context.incomplete[i].list.push({ type: RDFaProcessor.objectURI, value: newSubject })
          } else if (context.incomplete[i].forward) {
            // console.log(current.tagName+": completing forward triple "+context.incomplete[i].predicate+" with object="+newSubject)
            this.addTriple(current, context.subject, context.incomplete[i].predicate, { type: RDFaProcessor.objectURI, value: newSubject })
          } else {
            // console.log(current.tagName+": completing reverse triple with object="+context.subject)
            this.addTriple(current, newSubject, context.incomplete[i].predicate, { type: RDFaProcessor.objectURI, value: context.subject })
          }
        }
      }
      var childContext = null
      var listSubject = newSubject
      if (skip) {
        // TODO: should subject be null?
        childContext = this.push(context, context.subject)
        // TODO: should the entObject be passed along?  If not, then intermediary children will keep properties from being associated with incomplete triples.
        // TODO: Verify: if the current baseURI has changed and the parentObject is the parent's base URI, then the baseURI should change
        childContext.parentObject = removeHash(current.parentNode.baseURI) === context.parentObject ? removeHash(current.baseURI) : context.parentObject
        childContext.incomplete = context.incomplete
        childContext.language = language
        childContext.prefixes = prefixes
        childContext.vocabulary = vocabulary
      } else {
        childContext = this.push(context, newSubject)
        childContext.parentObject = currentObjectResource || (newSubject || context.subject)
        childContext.prefixes = prefixes
        childContext.incomplete = incomplete
        if (currentObjectResource) {
          // console.log("Generating new list mapping for "+currentObjectResource)
          listSubject = currentObjectResource
          listMapping = {}
          listMappingDifferent = true
        }
        childContext.listMapping = listMapping
        childContext.language = language
        childContext.vocabulary = vocabulary
      }
      if (listMappingDifferent) {
        // console.log("Pushing list parent "+current.localName)
        queue.unshift({ parent: current, context: context, subject: listSubject, listMapping: listMapping })
      }
      for (var child = current.lastChild; child; child = child.previousSibling) {
        if (child.nodeType === Node.ELEMENT_NODE) {
          // console.log("Pushing child "+child.localName)
          // child.baseURI = current.baseURI
          queue.unshift({ current: child, context: childContext })
        }
      }
    }
    if (this.inHTMLMode) {
      this.copyProperties()
    }
    for (let i = 0; i < this.finishedHandlers.length; i++) {
      this.finishedHandlers[i](node)
    }
  }

  push (parent, subject) {
    return {
      parent: parent,
      subject: subject || (parent ? parent.subject : null),
      parentObject: null,
      incomplete: [],
      listMapping: parent ? parent.listMapping : {},
      language: parent ? parent.language : this.language,
      prefixes: parent ? parent.prefixes : this.target.graph.prefixes,
      terms: parent ? parent.terms : this.target.graph.terms,
      vocabulary: parent ? parent.vocabulary : this.vocabulary
    }
  }

  resolveAndNormalize (base, uri) {
    // console.log("Joining " + uri + " to " + base + " making " +  Uri.join(uri, base))
    return Uri.join(uri, base) // @@ normalize?
  }

  setContext (node) {
    // We only recognized XHTML+RDFa 1.1 if the version is set propertyly
    if (node.localName === 'html' && node.getAttribute('version') === 'XHTML+RDFa 1.1') {
      this.setXHTMLContext()
    } else if (node.localName === 'html' || node.namespaceURI === 'http://www.w3.org/1999/xhtml') {
      if (typeof document !== 'undefined' && document.doctype) {
        if (document.doctype.publicId === '-//W3C//DTD XHTML+RDFa 1.0//EN' && document.doctype.systemId === 'http://www.w3.org/MarkUp/DTD/xhtml-rdfa-1.dtd') {
          console.log('WARNING: RDF 1.0 is not supported.  Defaulting to HTML5 mode.')
          this.setHTMLContext()
        } else if (document.doctype.publicId === '-//W3C//DTD XHTML+RDFa 1.1//EN' && document.doctype.systemId === 'http://www.w3.org/MarkUp/DTD/xhtml-rdfa-2.dtd') {
          this.setXHTMLContext()
        } else {
          this.setHTMLContext()
        }
      } else {
        this.setHTMLContext()
      }
    } else {
      this.setXMLContext()
    }
  }

  setHTMLContext () {
    this.setInitialContext()
    this.langAttributes = [
      {
        namespaceURI: 'http://www.w3.org/XML/1998/namespace',
        localName: 'lang'
      },
      { namespaceURI: null, localName: 'lang' }
    ]
    this.inXHTMLMode = false
    this.inHTMLMode = true
  }

  setInitialContext () {
    this.vocabulary = null
    // By default, the prefixes are terms are loaded to the RDFa 1.1. standard within the graph constructor
    this.langAttributes = [
      {
        namespaceURI: 'http://www.w3.org/XML/1998/namespace',
        localName: 'lang'
      }
    ]
  }

  setXHTMLContext () {
    this.setInitialContext()
    this.inXHTMLMode = true
    this.inHTMLMode = false
    this.langAttributes = [
      {
        namespaceURI: 'http://www.w3.org/XML/1998/namespace',
        localName: 'lang' },
      { namespaceURI: null, localName: 'lang' }
    ]
    // From http://www.w3.org/2011/rdfa-context/xhtml-rdfa-1.1
    this.target.graph.terms['alternate'] = 'http://www.w3.org/1999/xhtml/vocab#alternate'
    this.target.graph.terms['appendix'] = 'http://www.w3.org/1999/xhtml/vocab#appendix'
    this.target.graph.terms['bookmark'] = 'http://www.w3.org/1999/xhtml/vocab#bookmark'
    this.target.graph.terms['cite'] = 'http://www.w3.org/1999/xhtml/vocab#cite'
    this.target.graph.terms['chapter'] = 'http://www.w3.org/1999/xhtml/vocab#chapter'
    this.target.graph.terms['contents'] = 'http://www.w3.org/1999/xhtml/vocab#contents'
    this.target.graph.terms['copyright'] = 'http://www.w3.org/1999/xhtml/vocab#copyright'
    this.target.graph.terms['first'] = 'http://www.w3.org/1999/xhtml/vocab#first'
    this.target.graph.terms['glossary'] = 'http://www.w3.org/1999/xhtml/vocab#glossary'
    this.target.graph.terms['help'] = 'http://www.w3.org/1999/xhtml/vocab#help'
    this.target.graph.terms['icon'] = 'http://www.w3.org/1999/xhtml/vocab#icon'
    this.target.graph.terms['index'] = 'http://www.w3.org/1999/xhtml/vocab#index'
    this.target.graph.terms['last'] = 'http://www.w3.org/1999/xhtml/vocab#last'
    this.target.graph.terms['license'] = 'http://www.w3.org/1999/xhtml/vocab#license'
    this.target.graph.terms['meta'] = 'http://www.w3.org/1999/xhtml/vocab#meta'
    this.target.graph.terms['next'] = 'http://www.w3.org/1999/xhtml/vocab#next'
    this.target.graph.terms['prev'] = 'http://www.w3.org/1999/xhtml/vocab#prev'
    this.target.graph.terms['previous'] = 'http://www.w3.org/1999/xhtml/vocab#previous'
    this.target.graph.terms['section'] = 'http://www.w3.org/1999/xhtml/vocab#section'
    this.target.graph.terms['stylesheet'] = 'http://www.w3.org/1999/xhtml/vocab#stylesheet'
    this.target.graph.terms['subsection'] = 'http://www.w3.org/1999/xhtml/vocab#subsection'
    this.target.graph.terms['start'] = 'http://www.w3.org/1999/xhtml/vocab#start'
    this.target.graph.terms['top'] = 'http://www.w3.org/1999/xhtml/vocab#top'
    this.target.graph.terms['up'] = 'http://www.w3.org/1999/xhtml/vocab#up'
    this.target.graph.terms['p3pv1'] = 'http://www.w3.org/1999/xhtml/vocab#p3pv1'
    // other
    this.target.graph.terms['related'] = 'http://www.w3.org/1999/xhtml/vocab#related'
    this.target.graph.terms['role'] = 'http://www.w3.org/1999/xhtml/vocab#role'
    this.target.graph.terms['transformation'] = 'http://www.w3.org/1999/xhtml/vocab#transformation'
  }

  setXMLContext () {
    this.setInitialContext()
    this.inXHTMLMode = false
    this.inHTMLMode = false
  }

  tokenize (str) {
    return this.trim(str).split(/\s+/)
  }
  static tokenize (str) {
    return this.trim(str).split(/\s+/)
  }

  toRDFNodeObject (x) {
    if (typeof x === 'undefined') return undefined
    if (typeof x === 'string') {
      if (x.substring(0, 2) === '_:') {
        if (typeof this.blankNodes[x.substring(2)] === 'undefined') {
          this.blankNodes[x.substring(2)] = new BlankNode(x.substring(2))
        }
        return this.blankNodes[x.substring(2)]
      }
      return rdf.namedNode(x)
    }
    switch (x.type) {
      case RDFaProcessor.objectURI:
        if (x.value.substring(0, 2) === '_:') {
          if (typeof this.blankNodes[x.value.substring(2)] === 'undefined') {
            this.blankNodes[x.value.substring(2)] = new BlankNode(x.value.substring(2))
          }
          return this.blankNodes[x.value.substring(2)]
        }
        return rdf.namedNode(x.value)
      case RDFaProcessor.PlainLiteralURI:
        return new Literal(x.value, x.language || '')
      case RDFaProcessor.XMLLiteralURI:
      case RDFaProcessor.HTMLLiteralURI:
        var string = ''
        Object.keys(x.value).forEach(i => {
          string += Util.domToString(x.value[i], this.htmlOptions)
        })
        return new Literal(string, '', new NamedNode(x.type))
      default:
        return new Literal(x.value, '', new NamedNode(x.type))
    }
  }

  trim (str) {
    return str.replace(/^\s\s*/, '').replace(/\s\s*$/, '')
  }
  static trim (str) {
    return str.replace(/^\s\s*/, '').replace(/\s\s*$/, '')
  }
}

RDFaProcessor.XMLLiteralURI =
  'http://www.w3.org/1999/02/22-rdf-syntax-ns#XMLLiteral'
RDFaProcessor.HTMLLiteralURI = 'http://www.w3.org/1999/02/22-rdf-syntax-ns#HTML'
RDFaProcessor.PlainLiteralURI =
  'http://www.w3.org/1999/02/22-rdf-syntax-ns#PlainLiteral'
RDFaProcessor.objectURI = 'http://www.w3.org/1999/02/22-rdf-syntax-ns#object'
RDFaProcessor.typeURI = 'http://www.w3.org/1999/02/22-rdf-syntax-ns#type'
RDFaProcessor.nameChar =
  '[-A-Z_a-z\u00C0-\u00D6\u00D8-\u00F6\u00F8-\u02FF\u0370-\u037D\u037F-\u1FFF\u200C-\u200D\u2070-\u218F\u2C00-\u2FEF\u3001-\uD7FF\uF900-\uFDCF\uFDF0-\uFFFD\u10000-\uEFFFF\.0-9\u00B7\u0300-\u036F\u203F-\u2040]'
RDFaProcessor.nameStartChar =
  '[\u0041-\u005A\u0061-\u007A\u00C0-\u00D6\u00D8-\u00F6\u00F8-\u00FF\u0100-\u0131\u0134-\u013E\u0141-\u0148\u014A-\u017E\u0180-\u01C3\u01CD-\u01F0\u01F4-\u01F5\u01FA-\u0217\u0250-\u02A8\u02BB-\u02C1\u0386\u0388-\u038A\u038C\u038E-\u03A1\u03A3-\u03CE\u03D0-\u03D6\u03DA\u03DC\u03DE\u03E0\u03E2-\u03F3\u0401-\u040C\u040E-\u044F\u0451-\u045C\u045E-\u0481\u0490-\u04C4\u04C7-\u04C8\u04CB-\u04CC\u04D0-\u04EB\u04EE-\u04F5\u04F8-\u04F9\u0531-\u0556\u0559\u0561-\u0586\u05D0-\u05EA\u05F0-\u05F2\u0621-\u063A\u0641-\u064A\u0671-\u06B7\u06BA-\u06BE\u06C0-\u06CE\u06D0-\u06D3\u06D5\u06E5-\u06E6\u0905-\u0939\u093D\u0958-\u0961\u0985-\u098C\u098F-\u0990\u0993-\u09A8\u09AA-\u09B0\u09B2\u09B6-\u09B9\u09DC-\u09DD\u09DF-\u09E1\u09F0-\u09F1\u0A05-\u0A0A\u0A0F-\u0A10\u0A13-\u0A28\u0A2A-\u0A30\u0A32-\u0A33\u0A35-\u0A36\u0A38-\u0A39\u0A59-\u0A5C\u0A5E\u0A72-\u0A74\u0A85-\u0A8B\u0A8D\u0A8F-\u0A91\u0A93-\u0AA8\u0AAA-\u0AB0\u0AB2-\u0AB3\u0AB5-\u0AB9\u0ABD\u0AE0\u0B05-\u0B0C\u0B0F-\u0B10\u0B13-\u0B28\u0B2A-\u0B30\u0B32-\u0B33\u0B36-\u0B39\u0B3D\u0B5C-\u0B5D\u0B5F-\u0B61\u0B85-\u0B8A\u0B8E-\u0B90\u0B92-\u0B95\u0B99-\u0B9A\u0B9C\u0B9E-\u0B9F\u0BA3-\u0BA4\u0BA8-\u0BAA\u0BAE-\u0BB5\u0BB7-\u0BB9\u0C05-\u0C0C\u0C0E-\u0C10\u0C12-\u0C28\u0C2A-\u0C33\u0C35-\u0C39\u0C60-\u0C61\u0C85-\u0C8C\u0C8E-\u0C90\u0C92-\u0CA8\u0CAA-\u0CB3\u0CB5-\u0CB9\u0CDE\u0CE0-\u0CE1\u0D05-\u0D0C\u0D0E-\u0D10\u0D12-\u0D28\u0D2A-\u0D39\u0D60-\u0D61\u0E01-\u0E2E\u0E30\u0E32-\u0E33\u0E40-\u0E45\u0E81-\u0E82\u0E84\u0E87-\u0E88\u0E8A\u0E8D\u0E94-\u0E97\u0E99-\u0E9F\u0EA1-\u0EA3\u0EA5\u0EA7\u0EAA-\u0EAB\u0EAD-\u0EAE\u0EB0\u0EB2-\u0EB3\u0EBD\u0EC0-\u0EC4\u0F40-\u0F47\u0F49-\u0F69\u10A0-\u10C5\u10D0-\u10F6\u1100\u1102-\u1103\u1105-\u1107\u1109\u110B-\u110C\u110E-\u1112\u113C\u113E\u1140\u114C\u114E\u1150\u1154-\u1155\u1159\u115F-\u1161\u1163\u1165\u1167\u1169\u116D-\u116E\u1172-\u1173\u1175\u119E\u11A8\u11AB\u11AE-\u11AF\u11B7-\u11B8\u11BA\u11BC-\u11C2\u11EB\u11F0\u11F9\u1E00-\u1E9B\u1EA0-\u1EF9\u1F00-\u1F15\u1F18-\u1F1D\u1F20-\u1F45\u1F48-\u1F4D\u1F50-\u1F57\u1F59\u1F5B\u1F5D\u1F5F-\u1F7D\u1F80-\u1FB4\u1FB6-\u1FBC\u1FBE\u1FC2-\u1FC4\u1FC6-\u1FCC\u1FD0-\u1FD3\u1FD6-\u1FDB\u1FE0-\u1FEC\u1FF2-\u1FF4\u1FF6-\u1FFC\u2126\u212A-\u212B\u212E\u2180-\u2182\u3041-\u3094\u30A1-\u30FA\u3105-\u312C\uAC00-\uD7A3\u4E00-\u9FA5\u3007\u3021-\u3029_]'
RDFaProcessor.NCNAME = new RegExp('^' + RDFaProcessor.nameStartChar +
  RDFaProcessor.nameChar + '*$')

/*
RDFaProcessor.prototype.resolveAndNormalize = function(base,href) {
   var u = base.resolve(href)
   var parsed = this.parseURI(u)
   parsed.normalize()
   return parsed.spec
}
*/

RDFaProcessor.dateTimeTypes = [
  { pattern: /-?P(?:[0-9]+Y)?(?:[0-9]+M)?(?:[0-9]+D)?(?:T(?:[0-9]+H)?(?:[0-9]+M)?(?:[0-9]+(?:\.[0-9]+)?S)?)?/,
    type: 'http://www.w3.org/2001/XMLSchema#duration' },
  { pattern: /-?(?:[1-9][0-9][0-9][0-9]|0[1-9][0-9][0-9]|00[1-9][0-9]|000[1-9])-[0-9][0-9]-[0-9][0-9]T(?:[0-1][0-9]|2[0-4]):[0-5][0-9]:[0-5][0-9](?:\.[0-9]+)?(?:Z|[+\-][0-9][0-9]:[0-9][0-9])?/,
    type: 'http://www.w3.org/2001/XMLSchema#dateTime' },
  { pattern: /-?(?:[1-9][0-9][0-9][0-9]|0[1-9][0-9][0-9]|00[1-9][0-9]|000[1-9])-[0-9][0-9]-[0-9][0-9](?:Z|[+\-][0-9][0-9]:[0-9][0-9])?/,
    type: 'http://www.w3.org/2001/XMLSchema#date' },
  { pattern: /(?:[0-1][0-9]|2[0-4]):[0-5][0-9]:[0-5][0-9](?:\.[0-9]+)?(?:Z|[+\-][0-9][0-9]:[0-9][0-9])?/,
    type: 'http://www.w3.org/2001/XMLSchema#time' },
  { pattern: /-?(?:[1-9][0-9][0-9][0-9]|0[1-9][0-9][0-9]|00[1-9][0-9]|000[1-9])-[0-9][0-9]/,
    type: 'http://www.w3.org/2001/XMLSchema#gYearMonth' },
  { pattern: /-?[1-9][0-9][0-9][0-9]|0[1-9][0-9][0-9]|00[1-9][0-9]|000[1-9]/,
    type: 'http://www.w3.org/2001/XMLSchema#gYear' }
]

const parseRDFaDOM = RDFaProcessor.parseRDFaDOM
export { parseRDFaDOM }