NaturalIntelligence / fast-xml-parser / 22910077419

'use strict';

///@ts-check

import { getAllMatches, isExist } from '../util.js';

import xmlNode from './xmlNode.js';

import DocTypeReader from './DocTypeReader.js';

import toNumber from "strnum";

import getIgnoreAttributesFn from "../ignoreAttributes.js";

import { Expression, Matcher } from 'path-expression-matcher';

// const regx =

//   '<((!\\[CDATA\\[([\\s\\S]*?)(]]>))|((NAME:)?(NAME))([^>]*)>|((\\/)(NAME)\\s*>))([^<]*)'

//   .replace(/NAME/g, util.nameRegexp);

//const tagsRegx = new RegExp("<(\\/?[\\w:\\-\._]+)([^>]*)>(\\s*"+cdataRegx+")*([^<]+)?","g");

//const tagsRegx = new RegExp("<(\\/?)((\\w*:)?([\\w:\\-\._]+))([^>]*)>([^<]*)("+cdataRegx+"([^<]*))*([^<]+)?","g");

// Helper functions for attribute and namespace handling

/**

 * Extract raw attributes (without prefix) from prefixed attribute map

 * @param {object} prefixedAttrs - Attributes with prefix from buildAttributesMap

 * @param {object} options - Parser options containing attributeNamePrefix

 * @returns {object} Raw attributes for matcher

 */

function extractRawAttributes(prefixedAttrs, options) {

  // Handle attributesGroupName option

  const attrs = options.attributesGroupName

    ? prefixedAttrs[options.attributesGroupName]

    : prefixedAttrs;

  const rawAttrs = {};

  for (const key in attrs) {

    // Remove the attribute prefix to get raw name

    if (key.startsWith(options.attributeNamePrefix)) {

      const rawName = key.substring(options.attributeNamePrefix.length);

      rawAttrs[rawName] = attrs[key];

    } else {

      // Attribute without prefix (shouldn't normally happen, but be safe)

      rawAttrs[key] = attrs[key];

    }

  }

  return rawAttrs;

}

/**

 * Extract namespace from raw tag name

 * @param {string} rawTagName - Tag name possibly with namespace (e.g., "soap:Envelope")

 * @returns {string|undefined} Namespace or undefined

 */

function extractNamespace(rawTagName) {

  const colonIndex = rawTagName.indexOf(':');

  if (colonIndex !== -1 && colonIndex > 0) {

    const ns = rawTagName.substring(0, colonIndex);

    // Don't treat xmlns as a namespace

    if (ns !== 'xmlns') {

      return ns;

    }

  }

  return undefined;

}

export default class OrderedObjParser {

  constructor(options) {

    this.options = options;

    this.currentNode = null;

    this.tagsNodeStack = [];

    this.docTypeEntities = {};

    this.lastEntities = {

      "apos": { regex: /&(apos|#39|#x27);/g, val: "'" },

      "gt": { regex: /&(gt|#62|#x3E);/g, val: ">" },

      "lt": { regex: /&(lt|#60|#x3C);/g, val: "<" },

      "quot": { regex: /&(quot|#34|#x22);/g, val: "\"" },

    };

    this.ampEntity = { regex: /&(amp|#38|#x26);/g, val: "&" };

    this.htmlEntities = {

      "space": { regex: /&(nbsp|#160);/g, val: " " },

      // "lt" : { regex: /&(lt|#60);/g, val: "<" },

      // "gt" : { regex: /&(gt|#62);/g, val: ">" },

      // "amp" : { regex: /&(amp|#38);/g, val: "&" },

      // "quot" : { regex: /&(quot|#34);/g, val: "\"" },

      // "apos" : { regex: /&(apos|#39);/g, val: "'" },

      "cent": { regex: /&(cent|#162);/g, val: "¢" },

      "pound": { regex: /&(pound|#163);/g, val: "£" },

      "yen": { regex: /&(yen|#165);/g, val: "¥" },

      "euro": { regex: /&(euro|#8364);/g, val: "€" },

      "copyright": { regex: /&(copy|#169);/g, val: "©" },

      "reg": { regex: /&(reg|#174);/g, val: "®" },

      "inr": { regex: /&(inr|#8377);/g, val: "₹" },

      "num_dec": { regex: /&#([0-9]{1,7});/g, val: (_, str) => fromCodePoint(str, 10, "&#") },

      "num_hex": { regex: /&#x([0-9a-fA-F]{1,6});/g, val: (_, str) => fromCodePoint(str, 16, "&#x") },

    };

    this.addExternalEntities = addExternalEntities;

    this.parseXml = parseXml;

    this.parseTextData = parseTextData;

    this.resolveNameSpace = resolveNameSpace;

    this.buildAttributesMap = buildAttributesMap;

    this.isItStopNode = isItStopNode;

    this.replaceEntitiesValue = replaceEntitiesValue;

    this.readStopNodeData = readStopNodeData;

    this.saveTextToParentTag = saveTextToParentTag;

    this.addChild = addChild;

    this.ignoreAttributesFn = getIgnoreAttributesFn(this.options.ignoreAttributes)

    this.entityExpansionCount = 0;

    this.currentExpandedLength = 0;

    // Initialize path matcher for path-expression-matcher

    this.matcher = new Matcher();

    // Flag to track if current node is a stop node (optimization)

    this.isCurrentNodeStopNode = false;

    // Pre-compile stopNodes expressions

    if (this.options.stopNodes && this.options.stopNodes.length > 0) {

      this.stopNodeExpressions = [];

      for (let i = 0; i < this.options.stopNodes.length; i++) {

        const stopNodeExp = this.options.stopNodes[i];

        if (typeof stopNodeExp === 'string') {

          // Convert string to Expression object

          this.stopNodeExpressions.push(new Expression(stopNodeExp));

        } else if (stopNodeExp instanceof Expression) {

          // Already an Expression object

          this.stopNodeExpressions.push(stopNodeExp);

        }

      }

    }

  }

}

function addExternalEntities(externalEntities) {

  const entKeys = Object.keys(externalEntities);

  for (let i = 0; i < entKeys.length; i++) {

    const ent = entKeys[i];

    const escaped = ent.replace(/[.\-+*:]/g, '\\.');

    this.lastEntities[ent] = {

      regex: new RegExp("&" + escaped + ";", "g"),

      val: externalEntities[ent]

    }

  }

}

/**

 * @param {string} val

 * @param {string} tagName

 * @param {string|Matcher} jPath - jPath string or Matcher instance based on options.jPath

 * @param {boolean} dontTrim

 * @param {boolean} hasAttributes

 * @param {boolean} isLeafNode

 * @param {boolean} escapeEntities

 */

function parseTextData(val, tagName, jPath, dontTrim, hasAttributes, isLeafNode, escapeEntities) {

  if (val !== undefined) {

    if (this.options.trimValues && !dontTrim) {

      val = val.trim();

    }

    if (val.length > 0) {

      if (!escapeEntities) val = this.replaceEntitiesValue(val, tagName, jPath);

      // Pass jPath string or matcher based on options.jPath setting

      const jPathOrMatcher = this.options.jPath ? jPath.toString() : jPath;

      const newval = this.options.tagValueProcessor(tagName, val, jPathOrMatcher, hasAttributes, isLeafNode);

      if (newval === null || newval === undefined) {

        //don't parse

        return val;

      } else if (typeof newval !== typeof val || newval !== val) {

        //overwrite

        return newval;

      } else if (this.options.trimValues) {

        return parseValue(val, this.options.parseTagValue, this.options.numberParseOptions);

      } else {

        const trimmedVal = val.trim();

        if (trimmedVal === val) {

          return parseValue(val, this.options.parseTagValue, this.options.numberParseOptions);

        } else {

          return val;

        }

      }

    }

  }

}

function resolveNameSpace(tagname) {

  if (this.options.removeNSPrefix) {

    const tags = tagname.split(':');

    if (tags[0] === 'xmlns') {

      return '';

    }

    if (tags.length === 2) {

      tagname = prefix + tags[1];

    }

  }

  return tagname;

}

//TODO: change regex to capture NS

//const attrsRegx = new RegExp("([\\w\\-\\.\\:]+)\\s*=\\s*(['\"])((.|\n)*?)\\2","gm");

const attrsRegx = new RegExp('([^\\s=]+)\\s*(=\\s*([\'"])([\\s\\S]*?)\\3)?', 'gm');

function buildAttributesMap(attrStr, jPath, tagName) {

  if (this.options.ignoreAttributes !== true && typeof attrStr === 'string') {

    // attrStr = attrStr.replace(/\r?\n/g, ' ');

    //attrStr = attrStr || attrStr.trim();

    const matches = getAllMatches(attrStr, attrsRegx);

    const len = matches.length; //don't make it inline

    const attrs = {};

    // First pass: parse all attributes and update matcher with raw values

    // This ensures the matcher has all attribute values when processors run

    const rawAttrsForMatcher = {};

    for (let i = 0; i < len; i++) {

      const attrName = this.resolveNameSpace(matches[i][1]);

      const oldVal = matches[i][4];

      if (attrName.length && oldVal !== undefined) {

        let parsedVal = oldVal;

        if (this.options.trimValues) {

          parsedVal = parsedVal.trim();

        }

        parsedVal = this.replaceEntitiesValue(parsedVal, tagName, jPath);

        rawAttrsForMatcher[attrName] = parsedVal;

      }

    }

    // Update matcher with raw attribute values BEFORE running processors

    if (Object.keys(rawAttrsForMatcher).length > 0 && typeof jPath === 'object' && jPath.updateCurrent) {

      jPath.updateCurrent(rawAttrsForMatcher);

    }

    // Second pass: now process attributes with matcher having full attribute context

    for (let i = 0; i < len; i++) {

      const attrName = this.resolveNameSpace(matches[i][1]);

      // Convert jPath to string if needed for ignoreAttributesFn

      const jPathStr = this.options.jPath ? jPath.toString() : jPath;

      if (this.ignoreAttributesFn(attrName, jPathStr)) {

        continue

      }

      let oldVal = matches[i][4];

      let aName = this.options.attributeNamePrefix + attrName;

      if (attrName.length) {

        if (this.options.transformAttributeName) {

          aName = this.options.transformAttributeName(aName);

        }

        if (oldVal !== undefined) {

          if (this.options.trimValues) {

            oldVal = oldVal.trim();

          }

          oldVal = this.replaceEntitiesValue(oldVal, tagName, jPath);

          // Pass jPath string or matcher based on options.jPath setting

          const jPathOrMatcher = this.options.jPath ? jPath.toString() : jPath;

          const newVal = this.options.attributeValueProcessor(attrName, oldVal, jPathOrMatcher);

          } else if (typeof newVal !== typeof oldVal || newVal !== oldVal) {

            //overwrite

            attrs[aName] = newVal;

          } else {

            //parse

            attrs[aName] = parseValue(

              oldVal,

              this.options.parseAttributeValue,

              this.options.numberParseOptions

            );

          }

        } else if (this.options.allowBooleanAttributes) {

          attrs[aName] = true;

        }

      }

    }

    if (!Object.keys(attrs).length) {

      return;

    }

    if (this.options.attributesGroupName) {

      const attrCollection = {};

      attrCollection[this.options.attributesGroupName] = attrs;

      return attrCollection;

    }

    return attrs

  }

}

const parseXml = function (xmlData) {

  xmlData = xmlData.replace(/\r\n?/g, "\n"); //TODO: remove this line

  const xmlObj = new xmlNode('!xml');

  let currentNode = xmlObj;

  let textData = "";

  // Reset matcher for new document

  this.matcher.reset();

  // Reset entity expansion counters for this document

  this.entityExpansionCount = 0;

  this.currentExpandedLength = 0;

  const docTypeReader = new DocTypeReader(this.options.processEntities);

  for (let i = 0; i < xmlData.length; i++) {//for each char in XML data

    const ch = xmlData[i];

    if (ch === '<') {

      // const nextIndex = i+1;

      // const _2ndChar = xmlData[nextIndex];

      if (xmlData[i + 1] === '/') {//Closing Tag

        const closeIndex = findClosingIndex(xmlData, ">", i, "Closing Tag is not closed.")

        let tagName = xmlData.substring(i + 2, closeIndex).trim();

        if (this.options.removeNSPrefix) {

          const colonIndex = tagName.indexOf(":");

          if (colonIndex !== -1) {

            tagName = tagName.substr(colonIndex + 1);

          }

        }

        if (this.options.transformTagName) {

          tagName = this.options.transformTagName(tagName);

        }

        if (currentNode) {

          textData = this.saveTextToParentTag(textData, currentNode, this.matcher);

        }

        //check if last tag of nested tag was unpaired tag

        const lastTagName = this.matcher.getCurrentTag();

        if (tagName && this.options.unpairedTags.indexOf(tagName) !== -1) {

          throw new Error(`Unpaired tag can not be used as closing tag: </${tagName}>`);

        }

        // Pop the closing tag

        this.matcher.pop();

        this.isCurrentNodeStopNode = false; // Reset flag when closing tag

        currentNode = this.tagsNodeStack.pop();//avoid recursion, set the parent tag scope

        textData = "";

        i = closeIndex;

      } else if (xmlData[i + 1] === '?') {

        let tagData = readTagExp(xmlData, i, false, "?>");

        if (!tagData) throw new Error("Pi Tag is not closed.");

        textData = this.saveTextToParentTag(textData, currentNode, this.matcher);

        if ((this.options.ignoreDeclaration && tagData.tagName === "?xml") || this.options.ignorePiTags) {

          //do nothing

        } else {

          const childNode = new xmlNode(tagData.tagName);

          childNode.add(this.options.textNodeName, "");

          if (tagData.tagName !== tagData.tagExp && tagData.attrExpPresent) {

            childNode[":@"] = this.buildAttributesMap(tagData.tagExp, this.matcher, tagData.tagName);

          }

          this.addChild(currentNode, childNode, this.matcher, i);

        }

        i = tagData.closeIndex + 1;

      } else if (xmlData.substr(i + 1, 3) === '!--') {

        const endIndex = findClosingIndex(xmlData, "-->", i + 4, "Comment is not closed.")

        if (this.options.commentPropName) {

          const comment = xmlData.substring(i + 4, endIndex - 2);

          textData = this.saveTextToParentTag(textData, currentNode, this.matcher);

          currentNode.add(this.options.commentPropName, [{ [this.options.textNodeName]: comment }]);

        }

        i = endIndex;

      } else if (xmlData.substr(i + 1, 2) === '!D') {

        const result = docTypeReader.readDocType(xmlData, i);

        this.docTypeEntities = result.entities;

        i = result.i;

      } else if (xmlData.substr(i + 1, 2) === '![') {

        const closeIndex = findClosingIndex(xmlData, "]]>", i, "CDATA is not closed.") - 2;

        const tagExp = xmlData.substring(i + 9, closeIndex);

        textData = this.saveTextToParentTag(textData, currentNode, this.matcher);

        let val = this.parseTextData(tagExp, currentNode.tagname, this.matcher, true, false, true, true);

        if (val == undefined) val = "";

        //cdata should be set even if it is 0 length string

        if (this.options.cdataPropName) {

          currentNode.add(this.options.cdataPropName, [{ [this.options.textNodeName]: tagExp }]);

        } else {

          currentNode.add(this.options.textNodeName, val);

        }

        i = closeIndex + 2;

      } else {//Opening tag

        let result = readTagExp(xmlData, i, this.options.removeNSPrefix);

        // Safety check: readTagExp can return undefined

        let tagName = result.tagName;

        const rawTagName = result.rawTagName;

        let tagExp = result.tagExp;

        let attrExpPresent = result.attrExpPresent;

        let closeIndex = result.closeIndex;

        if (this.options.transformTagName) {

          //console.log(tagExp, tagName)

          const newTagName = this.options.transformTagName(tagName);

          if (tagExp === tagName) {

            tagExp = newTagName

          }

          tagName = newTagName;

        }

        if (this.options.strictReservedNames &&

          (tagName === this.options.commentPropName

            || tagName === this.options.cdataPropName

          )) {

          throw new Error(`Invalid tag name: ${tagName}`);

        }

        //save text as child node

        if (currentNode && textData) {

          if (currentNode.tagname !== '!xml') {

            //when nested tag is found

            textData = this.saveTextToParentTag(textData, currentNode, this.matcher, false);

          }

        }

        //check if last tag was unpaired tag

        const lastTag = currentNode;

        // Clean up self-closing syntax BEFORE processing attributes

        // This is where tagExp gets the trailing / removed

        let isSelfClosing = false;

        if (tagExp.length > 0 && tagExp.lastIndexOf("/") === tagExp.length - 1) {

          isSelfClosing = true;

          if (tagName[tagName.length - 1] === "/") {

            tagName = tagName.substr(0, tagName.length - 1);

            tagExp = tagName;

          } else {

            tagExp = tagExp.substr(0, tagExp.length - 1);

          }

          // Re-check attrExpPresent after cleaning

          attrExpPresent = (tagName !== tagExp);

        }

        // Now process attributes with CLEAN tagExp (no trailing /)

        let prefixedAttrs = null;

        let rawAttrs = {};

        let namespace = undefined;

        // Extract namespace from rawTagName

        namespace = extractNamespace(rawTagName);

        // Push tag to matcher FIRST (with empty attrs for now) so callbacks see correct path

        if (tagName !== xmlObj.tagname) {

          this.matcher.push(tagName, {}, namespace);

        }

        // Now build attributes - callbacks will see correct matcher state

        if (tagName !== tagExp && attrExpPresent) {

          // Build attributes (returns prefixed attributes for the tree)

          // Note: buildAttributesMap now internally updates the matcher with raw attributes

          prefixedAttrs = this.buildAttributesMap(tagExp, this.matcher, tagName);

          if (prefixedAttrs) {

            // Extract raw attributes (without prefix) for our use

            rawAttrs = extractRawAttributes(prefixedAttrs, this.options);

          }

        }

        // Now check if this is a stop node (after attributes are set)

        if (tagName !== xmlObj.tagname) {

          this.isCurrentNodeStopNode = this.isItStopNode(this.stopNodeExpressions, this.matcher);

        }

        const startIndex = i;

        if (this.isCurrentNodeStopNode) {

          let tagContent = "";

          // For self-closing tags, content is empty

          if (isSelfClosing) {

            i = result.closeIndex;

          }

          //unpaired tag

          else if (this.options.unpairedTags.indexOf(tagName) !== -1) {

            i = result.closeIndex;

          }

          //normal tag

          else {

            //read until closing tag is found

            const result = this.readStopNodeData(xmlData, rawTagName, closeIndex + 1);

            i = result.i;

            tagContent = result.tagContent;

          }

          const childNode = new xmlNode(tagName);

          if (prefixedAttrs) {

            childNode[":@"] = prefixedAttrs;

          }

          // For stop nodes, store raw content as-is without any processing

          childNode.add(this.options.textNodeName, tagContent);

          this.matcher.pop(); // Pop the stop node tag

          this.isCurrentNodeStopNode = false; // Reset flag

          this.addChild(currentNode, childNode, this.matcher, startIndex);

        } else {

          //selfClosing tag

          if (isSelfClosing) {

            if (this.options.transformTagName) {

              const newTagName = this.options.transformTagName(tagName);

              if (tagExp === tagName) {

                tagExp = newTagName

              }

              tagName = newTagName;

            }

            const childNode = new xmlNode(tagName);

            if (prefixedAttrs) {

              childNode[":@"] = prefixedAttrs;

            }

            this.addChild(currentNode, childNode, this.matcher, startIndex);

            this.matcher.pop(); // Pop self-closing tag

            this.isCurrentNodeStopNode = false; // Reset flag

          }

          else if (this.options.unpairedTags.indexOf(tagName) !== -1) {//unpaired tag

            const childNode = new xmlNode(tagName);

            if (prefixedAttrs) {

              childNode[":@"] = prefixedAttrs;

            }

            this.addChild(currentNode, childNode, this.matcher, startIndex);

            this.matcher.pop(); // Pop unpaired tag

            this.isCurrentNodeStopNode = false; // Reset flag

            i = result.closeIndex;

            // Continue to next iteration without changing currentNode

            continue;

          }

          //opening tag

          else {

            const childNode = new xmlNode(tagName);

            if (this.tagsNodeStack.length > this.options.maxNestedTags) {

              throw new Error("Maximum nested tags exceeded");

            }

            this.tagsNodeStack.push(currentNode);

            if (prefixedAttrs) {

              childNode[":@"] = prefixedAttrs;

            }

            this.addChild(currentNode, childNode, this.matcher, startIndex);

            currentNode = childNode;

          }

          textData = "";

          i = closeIndex;

        }

      }

    } else {

      textData += xmlData[i];

    }

  }

  return xmlObj.child;

}

function addChild(currentNode, childNode, matcher, startIndex) {

  // unset startIndex if not requested

  if (!this.options.captureMetaData) startIndex = undefined;

  // Pass jPath string or matcher based on options.jPath setting

  const jPathOrMatcher = this.options.jPath ? matcher.toString() : matcher;

  const result = this.options.updateTag(childNode.tagname, jPathOrMatcher, childNode[":@"])

  if (result === false) {

    //do nothing

  } else if (typeof result === "string") {

    childNode.tagname = result

    currentNode.addChild(childNode, startIndex);

}

/**

 * @param {object} val - Entity object with regex and val properties

 * @param {string} tagName - Tag name

 * @param {string|Matcher} jPath - jPath string or Matcher instance based on options.jPath

 */

function replaceEntitiesValue(val, tagName, jPath) {

  const entityConfig = this.options.processEntities;

  if (!entityConfig || !entityConfig.enabled) {

    return val;

  }

  // Check if tag is allowed to contain entities

  if (entityConfig.allowedTags) {

    const allowed = Array.isArray(entityConfig.allowedTags)

      ? entityConfig.allowedTags.includes(tagName)

    if (!allowed) {

      return val;

    }

  }

  // Apply custom tag filter if provided

  if (entityConfig.tagFilter) {

    if (!entityConfig.tagFilter(tagName, jPathOrMatcher)) {

      return val; // Skip based on custom filter

    }

  }

  // Replace DOCTYPE entities

  for (let entityName in this.docTypeEntities) {

    const entity = this.docTypeEntities[entityName];

    const matches = val.match(entity.regx);

    if (matches) {

      // Track expansions

      this.entityExpansionCount += matches.length;

      // Check expansion limit

      if (entityConfig.maxTotalExpansions &&

        this.entityExpansionCount > entityConfig.maxTotalExpansions) {

        throw new Error(

          `Entity expansion limit exceeded: ${this.entityExpansionCount} > ${entityConfig.maxTotalExpansions}`

        );

      }

      // Store length before replacement

      const lengthBefore = val.length;

      val = val.replace(entity.regx, entity.val);

      // Check expanded length immediately after replacement

      if (entityConfig.maxExpandedLength) {

        this.currentExpandedLength += (val.length - lengthBefore);

        if (this.currentExpandedLength > entityConfig.maxExpandedLength) {

          throw new Error(

            `Total expanded content size exceeded: ${this.currentExpandedLength} > ${entityConfig.maxExpandedLength}`

          );

        }

      }

    }

  }

  if (val.indexOf('&') === -1) return val;  // Early exit

  // Replace standard entities

  for (let entityName in this.lastEntities) {

    const entity = this.lastEntities[entityName];

    val = val.replace(entity.regex, entity.val);

  }

  if (val.indexOf('&') === -1) return val;  // Early exit

  // Replace HTML entities if enabled

  if (this.options.htmlEntities) {

    for (let entityName in this.htmlEntities) {

      const entity = this.htmlEntities[entityName];

      val = val.replace(entity.regex, entity.val);

    }

  }

  // Replace ampersand entity last

  val = val.replace(this.ampEntity.regex, this.ampEntity.val);

  return val;

}

function saveTextToParentTag(textData, parentNode, matcher, isLeafNode) {

  if (textData) { //store previously collected data as textNode

    if (isLeafNode === undefined) isLeafNode = parentNode.child.length === 0

    textData = this.parseTextData(textData,

      parentNode.tagname,

      matcher,

      false,

      isLeafNode);

    if (textData !== undefined && textData !== "")

      parentNode.add(this.options.textNodeName, textData);

    textData = "";

  }

  return textData;

}

//TODO: use jPath to simplify the logic

/**

 * @param {Array<Expression>} stopNodeExpressions - Array of compiled Expression objects

 * @param {Matcher} matcher - Current path matcher

 */

function isItStopNode(stopNodeExpressions, matcher) {

  if (!stopNodeExpressions || stopNodeExpressions.length === 0) return false;

  for (let i = 0; i < stopNodeExpressions.length; i++) {

    if (matcher.matches(stopNodeExpressions[i])) {

      return true;

    }

  }

  return false;

}

/**

 * Returns the tag Expression and where it is ending handling single-double quotes situation

 * @param {string} xmlData 

 * @param {number} i starting index

 * @returns 

 */

function tagExpWithClosingIndex(xmlData, i, closingChar = ">") {

  let attrBoundary;

  let tagExp = "";

  for (let index = i; index < xmlData.length; index++) {

    let ch = xmlData[index];

    if (attrBoundary) {

      if (ch === attrBoundary) attrBoundary = "";//reset

    } else if (ch === '"' || ch === "'") {

      attrBoundary = ch;

    } else if (ch === closingChar[0]) {

      if (closingChar[1]) {

        if (xmlData[index + 1] === closingChar[1]) {

          return {

            data: tagExp,

            index: index

          }

        }

      } else {

        return {

          data: tagExp,

          index: index

        }

      }

    } else if (ch === '\t') {

      ch = " "

    }

    tagExp += ch;

  }

}

function findClosingIndex(xmlData, str, i, errMsg) {

  const closingIndex = xmlData.indexOf(str, i);

  if (closingIndex === -1) {

    throw new Error(errMsg)

  } else {

    return closingIndex + str.length - 1;

  }

}

function readTagExp(xmlData, i, removeNSPrefix, closingChar = ">") {

  const result = tagExpWithClosingIndex(xmlData, i + 1, closingChar);

  if (!result) return;

  let tagExp = result.data;

  const closeIndex = result.index;

  const separatorIndex = tagExp.search(/\s/);

  let tagName = tagExp;

  let attrExpPresent = true;

  if (separatorIndex !== -1) {//separate tag name and attributes expression

    tagName = tagExp.substring(0, separatorIndex);

    tagExp = tagExp.substring(separatorIndex + 1).trimStart();

  }

  const rawTagName = tagName;

  if (removeNSPrefix) {

    const colonIndex = tagName.indexOf(":");

    if (colonIndex !== -1) {

      tagName = tagName.substr(colonIndex + 1);

      attrExpPresent = tagName !== result.data.substr(colonIndex + 1);

    }

  }

  return {

    tagName: tagName,

    tagExp: tagExp,

    closeIndex: closeIndex,

    attrExpPresent: attrExpPresent,

    rawTagName: rawTagName,

  }

}

/**

 * find paired tag for a stop node

 * @param {string} xmlData 

 * @param {string} tagName 

 * @param {number} i 

 */

function readStopNodeData(xmlData, tagName, i) {

  const startIndex = i;

  // Starting at 1 since we already have an open tag