svgdom/src/utils/NodeIterator.js

Straightforward DOM implementation for SVG, HTML and XML

import { NodeFilter } from '../dom/NodeFilter.js'

const showThisNode = (whatToShow, node) => {
  if (whatToShow === NodeFilter.SHOW_ALL) return true
  if (whatToShow & NodeFilter.SHOW_ELEMENT && node.nodeType === node.ELEMENT_NODE) return true
  if (whatToShow & NodeFilter.SHOW_TEXT && node.nodeType === node.TEXT_NODE) return true
  if (whatToShow & NodeFilter.SHOW_ENTITY_REFERENCE && node.nodeType === node.ENTITY_REFERENCE_NODE) return true
  if (whatToShow & NodeFilter.SHOW_ENTITY && node.nodeType === node.ENTITY_NODE) return true
  if (whatToShow & NodeFilter.SHOW_PROCESSING_INSTRUCTION && node.nodeType === node.PROCESSING_INSTRUCTION_NODE) return true
  if (whatToShow & NodeFilter.SHOW_COMMENT && node.nodeType === node.COMMENT_NODE) return true
  if (whatToShow & NodeFilter.SHOW_DOCUMENT && node.nodeType === node.DOCUMENT_NODE) return true
  if (whatToShow & NodeFilter.SHOW_DOCUMENT_TYPE && node.nodeType === node.DOCUMENT_TYPE_NODE) return true
  if (whatToShow & NodeFilter.SHOW_DOCUMENT_FRAGMENT && node.nodeType === node.DOCUMENT_FRAGMENT_NODE) return true
  if (whatToShow & NodeFilter.SHOW_NOTATION && node.nodeType === node.NOTATION_NODE) return true
  return false
}

export class NodeIterator {
  constructor (root, whatToShow = NodeFilter.SHOW_ALL, filter = () => NodeFilter.FILTER_ACCEPT, includeParent = true) {
    this.root = includeParent ? { childNodes: [ root ] } : root
    this.whatToShow = whatToShow
    this.filter = filter
  }

  * [Symbol.iterator] () {
    const nodes = this.root.childNodes

    for (const node of nodes) {
      if (!showThisNode(this.whatToShow, node)) continue

      const filterRet = this.filter(node)

      if (filterRet === NodeFilter.FILTER_REJECT) continue
      if (filterRet === NodeFilter.FILTER_ACCEPT) {
        yield node
      }

      yield * new NodeIterator(node, this.whatToShow, this.filter, false)
    }

    return this
  }
}