h54s/src/tables/utils.js

HTML5 Data Adapter for SAS

const h54sError = require('../error.js');
const logs = require('../logs.js');

/*
* Convert table object to Sas readable object
*
* @param {object} inObject - Object to convert
*
*/
module.exports.convertTableObject = function(inObject, chunkThreshold) {
  const self            = this;

  if(chunkThreshold > 30000) {
    console.warn('You should not set threshold larger than 30kb because of the SAS limitations');
  }

  // first check that the object is an array
  if (typeof (inObject) !== 'object') {
    throw new h54sError('argumentError', 'The parameter passed to checkAndGetTypeObject is not an object');
  }

  const arrayLength = inObject.length;
  if (typeof (arrayLength) !== 'number') {
    throw new h54sError('argumentError', 'The parameter passed to checkAndGetTypeObject does not have a valid length and is most likely not an array');
  }

  const existingCols = {}; // this is just to make lookup easier rather than traversing array each time. Will transform after

  // function checkAndSetArray - this will check an inObject current key against the existing typeArray and either return -1 if there
  // is a type mismatch or add an element and update/increment the length if needed

  function checkAndIncrement(colSpec) {
    if (typeof (existingCols[colSpec.colName]) === 'undefined') {
      existingCols[colSpec.colName]           = {};
      existingCols[colSpec.colName].colName   = colSpec.colName;
      existingCols[colSpec.colName].colType   = colSpec.colType;
      existingCols[colSpec.colName].colLength = colSpec.colLength > 0 ? colSpec.colLength : 1;
      return 0; // all ok
    }
    // check type match
    if (existingCols[colSpec.colName].colType !== colSpec.colType) {
      return -1; // there is a fudge in the typing
    }
    if (existingCols[colSpec.colName].colLength < colSpec.colLength) {
      existingCols[colSpec.colName].colLength = colSpec.colLength > 0 ? colSpec.colLength : 1; // increment the max length of this column
      return 0;
    }
  }
  let chunkArrayCount         = 0; // this is for keeping tabs on how long the current array string would be
  const targetArray           = []; // this is the array of target arrays
  let currentTarget           = 0;
  targetArray[currentTarget]  = [];
  let j                       = 0;
  for (let i = 0; i < inObject.length; i++) {
    targetArray[currentTarget][j] = {};
    let chunkRowCount             = 0;

    for (let key in inObject[i]) {
      const thisSpec  = {};
      const thisValue = inObject[i][key];

      //skip undefined values
      if(thisValue === undefined || thisValue === null) {
        continue;
      }

      //throw an error if there's NaN value
      if(typeof thisValue === 'number' && isNaN(thisValue)) {
        throw new h54sError('typeError', 'NaN value in one of the values (columns) is not allowed');
      }

      if(thisValue === -Infinity || thisValue === Infinity) {
        throw new h54sError('typeError', thisValue.toString() + ' value in one of the values (columns) is not allowed');
      }

      if(thisValue === true || thisValue === false) {
        throw new h54sError('typeError', 'Boolean value in one of the values (columns) is not allowed');
      }

      // get type... if it is an object then convert it to json and store as a string
      const thisType  = typeof (thisValue);

      if (thisType === 'number') { // straightforward number
        if(thisValue < Number.MIN_SAFE_INTEGER || thisValue > Number.MAX_SAFE_INTEGER) {
          logs.addApplicationLog('Object[' + i + '].' + key + ' - This value exceeds expected numeric precision.');
        }
        thisSpec.colName                    = key;
        thisSpec.colType                    = 'num';
        thisSpec.colLength                  = 8;
        thisSpec.encodedLength              = thisValue.toString().length;
        targetArray[currentTarget][j][key]  = thisValue;
      } else if (thisType === 'string') {
        thisSpec.colName    = key;
        thisSpec.colType    = 'string';
        thisSpec.colLength  = thisValue.length;

        if (thisValue === "") {
          targetArray[currentTarget][j][key] = " ";
        } else {
          targetArray[currentTarget][j][key] = encodeURIComponent(thisValue).replace(/'/g, '%27');
        }
        thisSpec.encodedLength = targetArray[currentTarget][j][key].length;
      } else if(thisValue instanceof Date) {
      	console.log("ERROR VALUE ", thisValue)
      	console.log("TYPEOF VALUE ", typeof thisValue)
        throw new h54sError('typeError', 'Date type not supported. Please use h54s.toSasDateTime function to convert it');
      } else if (thisType == 'object') {
        thisSpec.colName                    = key;
        thisSpec.colType                    = 'json';
        thisSpec.colLength                  = JSON.stringify(thisValue).length;
        targetArray[currentTarget][j][key]  = encodeURIComponent(JSON.stringify(thisValue)).replace(/'/g, '%27');
        thisSpec.encodedLength              = targetArray[currentTarget][j][key].length;
      }

      chunkRowCount = chunkRowCount + 6 + key.length + thisSpec.encodedLength;

      if (checkAndIncrement(thisSpec) == -1) {
        throw new h54sError('typeError', 'There is a type mismatch in the array between values (columns) of the same name.');
      }
    }

    //remove last added row if it's empty
    if(Object.keys(targetArray[currentTarget][j]).length === 0) {
      targetArray[currentTarget].splice(j, 1);
      continue;
    }

    if (chunkRowCount > chunkThreshold) {
      throw new h54sError('argumentError', 'Row ' + j + ' exceeds size limit of 32kb');
    } else if(chunkArrayCount + chunkRowCount > chunkThreshold) {
      //create new array if this one is full and move the last item to the new array
      const lastRow = targetArray[currentTarget].pop(); // get rid of that last row
      currentTarget++; // move onto the next array
      targetArray[currentTarget]  = [lastRow]; // make it an array
      j                           = 0; // initialise new row counter for new array - it will be incremented at the end of the function
      chunkArrayCount             = chunkRowCount; // this is the new chunk max size
    } else {
      chunkArrayCount = chunkArrayCount + chunkRowCount;
    }
    j++;
  }

  // reformat existingCols into an array so sas can parse it;
  const specArray = [];
  for (let k in existingCols) {
    specArray.push(existingCols[k]);
  }
  return {
    spec:       specArray,
    data:       targetArray,
    jsonLength: chunkArrayCount
  }; // the spec will be the macro[0], with the data split into arrays of macro[1-n]
  // means in terms of dojo xhr object at least they need to go into the same array
};

/*
* Convert javascript date to sas time
*
* @param {object} jsDate - javascript Date object
*
*/
module.exports.toSasDateTime = function (jsDate) {
  const basedate = new Date("January 1, 1960 00:00:00");
  const currdate = jsDate;

  // offsets for UTC and timezones and BST
  const baseOffset = basedate.getTimezoneOffset(); // in minutes
  const currOffset = currdate.getTimezoneOffset(); // in minutes

  // convert currdate to a sas datetime
  const offsetSecs    = (currOffset - baseOffset) * 60; // offsetDiff is in minutes to start with
  const baseDateSecs  = basedate.getTime() / 1000; // get rid of ms
  const currdateSecs  = currdate.getTime() / 1000; // get rid of ms
  const sasDatetime   = Math.round(currdateSecs - baseDateSecs - offsetSecs); // adjust

  return sasDatetime;
};