NaturalIntelligence / fast-xml-parser / 15517131831

'use strict';

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

const defaultOptions = {

  allowBooleanAttributes: false, //A tag can have attributes without any value

  unpairedTags: []

};

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

export function validate(xmlData, options) {

  options = Object.assign({}, defaultOptions, options);

  //xmlData = xmlData.replace(/(\r\n|\n|\r)/gm,"");//make it single line

  //xmlData = xmlData.replace(/(^\s*<\?xml.*?\?>)/g,"");//Remove XML starting tag

  //xmlData = xmlData.replace(/(<!DOCTYPE[\s\w\"\.\/\-\:]+(\[.*\])*\s*>)/g,"");//Remove DOCTYPE

  const tags = [];

  let tagFound = false;

  //indicates that the root tag has been closed (aka. depth 0 has been reached)

  let reachedRoot = false;

  if (xmlData[0] === '\ufeff') {

    // check for byte order mark (BOM)

    xmlData = xmlData.substr(1);

  }

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

    if (xmlData[i] === '<' && xmlData[i+1] === '?') {

      i+=2;

      i = readPI(xmlData,i);

      if (i.err) return i;

    }else if (xmlData[i] === '<') {

      //starting of tag

      //read until you reach to '>' avoiding any '>' in attribute value

      let tagStartPos = i;

      i++;

      if (xmlData[i] === '!') {

        i = readCommentAndCDATA(xmlData, i);

        continue;

      } else {

        let closingTag = false;

        if (xmlData[i] === '/') {

          //closing tag

          closingTag = true;

          i++;

        }

        //read tagname

        let tagName = '';

        for (; i < xmlData.length &&

          xmlData[i] !== '>' &&

          xmlData[i] !== ' ' &&

          xmlData[i] !== '\t' &&

          xmlData[i] !== '\n' &&

          xmlData[i] !== '\r'; i++

        ) {

          tagName += xmlData[i];

        }

        tagName = tagName.trim();

        //console.log(tagName);

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

          //self closing tag without attributes

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

          //continue;

          i--;

        }

        if (!validateTagName(tagName)) {

          let msg;

          if (tagName.trim().length === 0) {

            msg = "Invalid space after '<'.";

          } else {

            msg = "Tag '"+tagName+"' is an invalid name.";

          }

          return getErrorObject('InvalidTag', msg, getLineNumberForPosition(xmlData, i));

        }

        const result = readAttributeStr(xmlData, i);

        if (result === false) {

          return getErrorObject('InvalidAttr', "Attributes for '"+tagName+"' have open quote.", getLineNumberForPosition(xmlData, i));

        }

        let attrStr = result.value;

        i = result.index;

        if (attrStr[attrStr.length - 1] === '/') {

          //self closing tag

          const attrStrStart = i - attrStr.length;

          attrStr = attrStr.substring(0, attrStr.length - 1);

          const isValid = validateAttributeString(attrStr, options);

          if (isValid === true) {

            tagFound = true;

            //continue; //text may presents after self closing tag

          } else {

            //the result from the nested function returns the position of the error within the attribute

            //in order to get the 'true' error line, we need to calculate the position where the attribute begins (i - attrStr.length) and then add the position within the attribute

            //this gives us the absolute index in the entire xml, which we can use to find the line at last

            return getErrorObject(isValid.err.code, isValid.err.msg, getLineNumberForPosition(xmlData, attrStrStart + isValid.err.line));

          }

        } else if (closingTag) {

          if (!result.tagClosed) {

            return getErrorObject('InvalidTag', "Closing tag '"+tagName+"' doesn't have proper closing.", getLineNumberForPosition(xmlData, i));

          } else if (attrStr.trim().length > 0) {

            return getErrorObject('InvalidTag', "Closing tag '"+tagName+"' can't have attributes or invalid starting.", getLineNumberForPosition(xmlData, tagStartPos));

          } else if (tags.length === 0) {

            return getErrorObject('InvalidTag', "Closing tag '"+tagName+"' has not been opened.", getLineNumberForPosition(xmlData, tagStartPos));

          } else {

            const otg = tags.pop();

            if (tagName !== otg.tagName) {

              let openPos = getLineNumberForPosition(xmlData, otg.tagStartPos);

              return getErrorObject('InvalidTag',

                "Expected closing tag '"+otg.tagName+"' (opened in line "+openPos.line+", col "+openPos.col+") instead of closing tag '"+tagName+"'.",

                getLineNumberForPosition(xmlData, tagStartPos));

            }

            //when there are no more tags, we reached the root level.

            if (tags.length == 0) {

              reachedRoot = true;

            }

          }

        } else {

          const isValid = validateAttributeString(attrStr, options);

          if (isValid !== true) {

            //the result from the nested function returns the position of the error within the attribute

            //in order to get the 'true' error line, we need to calculate the position where the attribute begins (i - attrStr.length) and then add the position within the attribute

            //this gives us the absolute index in the entire xml, which we can use to find the line at last

            return getErrorObject(isValid.err.code, isValid.err.msg, getLineNumberForPosition(xmlData, i - attrStr.length + isValid.err.line));

          }

          //if the root level has been reached before ...

          if (reachedRoot === true) {

            return getErrorObject('InvalidXml', 'Multiple possible root nodes found.', getLineNumberForPosition(xmlData, i));

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

            //don't push into stack

          } else {

            tags.push({tagName, tagStartPos});

          }

          tagFound = true;

        }

        //skip tag text value

        //It may include comments and CDATA value

        for (i++; i < xmlData.length; i++) {

          if (xmlData[i] === '<') {

            if (xmlData[i + 1] === '!') {

              //comment or CADATA

              i++;

              i = readCommentAndCDATA(xmlData, i);

              continue;

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

              i = readPI(xmlData, ++i);

            } else{

              break;

            }

          } else if (xmlData[i] === '&') {

            const afterAmp = validateAmpersand(xmlData, i);

            if (afterAmp == -1)

              return getErrorObject('InvalidChar', "char '&' is not expected.", getLineNumberForPosition(xmlData, i));

            i = afterAmp;

          }else{

            if (reachedRoot === true && !isWhiteSpace(xmlData[i])) {

              return getErrorObject('InvalidXml', "Extra text at the end", getLineNumberForPosition(xmlData, i));

            }

          }

        } //end of reading tag text value

        if (xmlData[i] === '<') {

          i--;

        }

      }

    } else {

      if ( isWhiteSpace(xmlData[i])) {

        continue;

      }

      return getErrorObject('InvalidChar', "char '"+xmlData[i]+"' is not expected.", getLineNumberForPosition(xmlData, i));

    }

  }

  if (!tagFound) {

    return getErrorObject('InvalidXml', 'Start tag expected.', 1);

  }else if (tags.length == 1) {

      return getErrorObject('InvalidTag', "Unclosed tag '"+tags[0].tagName+"'.", getLineNumberForPosition(xmlData, tags[0].tagStartPos));

  return true;

};

function isWhiteSpace(char){

  return char === ' ' || char === '\t' || char === '\n'  || char === '\r';

}

/**

 * Read Processing insstructions and skip

 * @param {*} xmlData

 * @param {*} i

 */

function readPI(xmlData, i) {

  const start = i;

  for (; i < xmlData.length; i++) {

    if (xmlData[i] == '?' || xmlData[i] == ' ') {

      //tagname

      const tagname = xmlData.substr(start, i - start);

      if (i > 5 && tagname === 'xml') {

        return getErrorObject('InvalidXml', 'XML declaration allowed only at the start of the document.', getLineNumberForPosition(xmlData, i));

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

        //check if valid attribut string

        i++;

        break;

      } else {

        continue;

      }

    }

  }

  return i;

}

function readCommentAndCDATA(xmlData, i) {

  if (xmlData.length > i + 5 && xmlData[i + 1] === '-' && xmlData[i + 2] === '-') {

    //comment

    for (i += 3; i < xmlData.length; i++) {

      if (xmlData[i] === '-' && xmlData[i + 1] === '-' && xmlData[i + 2] === '>') {

        i += 2;

        break;

      }

    }

  } else if (

    xmlData.length > i + 8 &&

    xmlData[i + 1] === 'D' &&

    xmlData[i + 2] === 'O' &&

    xmlData[i + 3] === 'C' &&

    xmlData[i + 4] === 'T' &&

    xmlData[i + 5] === 'Y' &&

    xmlData[i + 6] === 'P' &&

    xmlData[i + 7] === 'E'

  ) {

    let angleBracketsCount = 1;

    for (i += 8; i < xmlData.length; i++) {

      if (xmlData[i] === '<') {

        angleBracketsCount++;

      } else if (xmlData[i] === '>') {

        angleBracketsCount--;

        if (angleBracketsCount === 0) {

          break;

        }

      }

    }

  } else if (

    xmlData.length > i + 9 &&

    xmlData[i + 1] === '[' &&

    xmlData[i + 2] === 'C' &&

    xmlData[i + 3] === 'D' &&

    xmlData[i + 4] === 'A' &&

    xmlData[i + 5] === 'T' &&

    xmlData[i + 6] === 'A' &&

    xmlData[i + 7] === '['

  ) {

    for (i += 8; i < xmlData.length; i++) {

      if (xmlData[i] === ']' && xmlData[i + 1] === ']' && xmlData[i + 2] === '>') {

        i += 2;

        break;

      }

    }

  }

  return i;

}

const doubleQuote = '"';

const singleQuote = "'";

/**

 * Keep reading xmlData until '<' is found outside the attribute value.

 * @param {string} xmlData

 * @param {number} i

 */

function readAttributeStr(xmlData, i) {

  let attrStr = '';

  let startChar = '';

  let tagClosed = false;

  for (; i < xmlData.length; i++) {

    if (xmlData[i] === doubleQuote || xmlData[i] === singleQuote) {

      if (startChar === '') {

        startChar = xmlData[i];

      } else if (startChar !== xmlData[i]) {

        //if vaue is enclosed with double quote then single quotes are allowed inside the value and vice versa

      } else {

        startChar = '';

      }

    } else if (xmlData[i] === '>') {

      if (startChar === '') {

        tagClosed = true;

        break;

      }

    }

    attrStr += xmlData[i];

  }

  if (startChar !== '') {

    return false;

  }

  return {

    value: attrStr,

    index: i,

    tagClosed: tagClosed

  };

}

/**

 * Select all the attributes whether valid or invalid.

 */

const validAttrStrRegxp = new RegExp('(\\s*)([^\\s=]+)(\\s*=)?(\\s*([\'"])(([\\s\\S])*?)\\5)?', 'g');

//attr, ="sd", a="amit's", a="sd"b="saf", ab  cd=""

function validateAttributeString(attrStr, options) {

  //console.log("start:"+attrStr+":end");

  //if(attrStr.trim().length === 0) return true; //empty string

  const matches = getAllMatches(attrStr, validAttrStrRegxp);

  const attrNames = {};

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

    if (matches[i][1].length === 0) {

      //nospace before attribute name: a="sd"b="saf"

      return getErrorObject('InvalidAttr', "Attribute '"+matches[i][2]+"' has no space in starting.", getPositionFromMatch(matches[i]))

    } else if (matches[i][3] !== undefined && matches[i][4] === undefined) {

      return getErrorObject('InvalidAttr', "Attribute '"+matches[i][2]+"' is without value.", getPositionFromMatch(matches[i]));

    } else if (matches[i][3] === undefined && !options.allowBooleanAttributes) {

      //independent attribute: ab

      return getErrorObject('InvalidAttr', "boolean attribute '"+matches[i][2]+"' is not allowed.", getPositionFromMatch(matches[i]));

    }

    /* else if(matches[i][6] === undefined){//attribute without value: ab=

                    return { err: { code:"InvalidAttr",msg:"attribute " + matches[i][2] + " has no value assigned."}};

                } */

    const attrName = matches[i][2];

    if (!validateAttrName(attrName)) {

      return getErrorObject('InvalidAttr', "Attribute '"+attrName+"' is an invalid name.", getPositionFromMatch(matches[i]));

    }

    if (!attrNames.hasOwnProperty(attrName)) {

      //check for duplicate attribute.

      attrNames[attrName] = 1;

    } else {

      return getErrorObject('InvalidAttr', "Attribute '"+attrName+"' is repeated.", getPositionFromMatch(matches[i]));

    }

  }

  return true;

}

function validateNumberAmpersand(xmlData, i) {

  let re = /\d/;

  if (xmlData[i] === 'x') {

    i++;

    re = /[\da-fA-F]/;

  }

  for (; i < xmlData.length; i++) {

    if (xmlData[i] === ';')

      return i;

    if (!xmlData[i].match(re))

      break;

  }

  return -1;

}

function validateAmpersand(xmlData, i) {

  // https://www.w3.org/TR/xml/#dt-charref

  i++;

  if (xmlData[i] === ';')

  if (xmlData[i] === '#') {

    i++;

    return validateNumberAmpersand(xmlData, i);

  }

  let count = 0;

  for (; i < xmlData.length; i++, count++) {

    if (xmlData[i].match(/\w/) && count < 20)

      continue;

    if (xmlData[i] === ';')

      break;

    return -1;

  }

  return i;

}

function getErrorObject(code, message, lineNumber) {

  return {

    err: {

      code: code,

      msg: message,

      line: lineNumber.line || lineNumber,

      col: lineNumber.col,

    },

  };

}

function validateAttrName(attrName) {

  return isName(attrName);

}

// const startsWithXML = /^xml/i;

function validateTagName(tagname) {

  return isName(tagname) /* && !tagname.match(startsWithXML) */;

}

//this function returns the line number for the character at the given index

function getLineNumberForPosition(xmlData, index) {

  const lines = xmlData.substring(0, index).split(/\r?\n/);

  return {

    line: lines.length,

    // column number is last line's length + 1, because column numbering starts at 1:

    col: lines[lines.length - 1].length + 1

  };

}

//this function returns the position of the first character of match within attrStr

function getPositionFromMatch(match) {

  return match.startIndex + match[1].length;

}