svgdom/src/dom/html/HTMLParser.js

Straightforward DOM implementation for SVG, HTML and XML

import sax from 'sax'

// TODO: Its an XMLParser not HTMLParser!!
export const HTMLParser = function (str, el) {
  let currentTag = el
  // const namespaces = { xmlns: el.getAttribute('xmlns') }
  let document = el.ownerDocument
  let cdata = null

  // sax expects a root element but we also missuse it to parse fragments
  if (el.nodeType !== el.DOCUMENT_NODE) {
    str = '<svgdom:wrapper xmlns:svgdom="svgdom:rocks">' + str + '</svgdom:wrapper>'
  } else {
    document = el
  }

  const parser = sax.parser(true, {
    // lowercase: true,
    xmlns: true,
    strictEntities: true
  })

  parser.onerror = (e) => {
    throw e
  }

  parser.ondoctype = () => {
    if (currentTag !== document) {
      throw new Error('Doctype can only be appended to document')
    }
    currentTag.appendChild(document.implementation.createDocumentType())
  }

  parser.ontext = (str) => currentTag.appendChild(document.createTextNode(str))
  parser.oncomment = (str) => currentTag.appendChild(document.createComment(str))

  // parser.onopennamespace = ns => {
  //   namespaces[ns.prefix] = ns.uri
  // }
  // parser.onclosenamespace = ns => {
  //   delete namespaces[ns.prefix]
  // }

  parser.onopentag = node => {
    if (node.name === 'svgdom:wrapper') return

    const attrs = node.attributes

    const uri = node.uri || currentTag.lookupNamespaceURI(node.prefix || null)

    const newElement = document.createElementNS(uri, node.name)

    for (const [ name, node ] of Object.entries(attrs)) {
      newElement.setAttributeNS(node.uri, name, node.value)
    }

    currentTag.appendChild(newElement)
    currentTag = newElement
  }

  parser.onclosetag = tagName => {
    if (tagName === 'svgdom:wrapper') return

    currentTag = currentTag.parentNode
  }

  parser.onopencdata = () => {
    cdata = document.createCDATASection('')
  }

  parser.oncdata = (str) => {
    cdata.appendData(str)
  }

  parser.onclosecdata = () => {
    currentTag.appendChild(cdata)
  }

  parser.write(str)
}