Storing data in empty Array returns empty Array (only in AppScript)-CodePudding

I wrote a simple iterator to loop trough a JSON object and parse the object into a new form. This works as expected in almost any JS environment. (For example in the console( However, the function below returns an empty array when executed in AppScript.

returns : [[], [], [], [], []]

This problem seems to be AppScript specific. Before I submit a bug through Google Developer Group I like to understand if this might be an App Script specific and intended behavior.

var TableData = [["20220301","(none)","(direct)","3","1","1"],["20220301","organic","google","3","1","1"],["20220302","(none)","(direct)","4","2","2"],["20220302","organic","bing","1","1","1"],["20220303","(none)","(direct)","1","1","1"]]

function parseBQData(TableData, request) {
  try {
    
    // store the array of dimensions and metrics in a variable called 'fields'
    var fields = ["date", "medium", "source", "pageviews", "sessions", "users"]

    // create a new empty array to store the parsed data
    var newTableData = new Array();
    
    // loop through each row in the TableData
    for (var i = 0; i < TableData.length; i  ) {
      
      // create a new empty array to store the current row
      var wrapper = new Array();
      
      // loop through each column in the row
      for (var j = 0; j < fields.length; j  ) {
        
        // store the column data in the current row array, using the column header as the key
        wrapper[fields[j]] = TableData[i][j];
        

      Logger.log("Wrapper : "   wrapper) // This returns "Wrapper : "

      }
      
      // add the current row to the new array of parsed data
      newTableData.push(wrapper);
    }
    
    
    // return the new array of parsed data
    return newTableData;
  
  // if there is an error parsing the data, print the error to the log
  } catch (e) {
    Logger.log("Error parsing data")
    Logger.log(e)
  }
}

CodePudding user response：

did not try in App Script but works fine with browser JS console :

var TableData = [["20220301","(none)","(direct)","3","1","1"],["20220301","organic","google","3","1","1"],["20220302","(none)","(direct)","4","2","2"],["20220302","organic","bing","1","1","1"],["20220303","(none)","(direct)","1","1","1"]]

function parseBQData(TableData, request) {
  try {
    var fields = ["date", "medium", "source", "pageviews", "sessions", "users"];
    var newTableData = new Array();
    for (var i = 0; i < TableData.length; i  ) {
      var wrapper = new Array();
      for (var j = 0; j < fields.length; j  ) {
        wrapper[fields[j]] = TableData[i][j];
      console.log("Wrapper : "   wrapper)
      }
      newTableData.push(wrapper);
    }
    return newTableData;
  } catch (e) {
    console.log("Error parsing data")
    console.log(e)
  }
}
parseBQData(TableData, 0);

Logs :

Wrapper : 
(5) [Array(0), Array(0), Array(0), Array(0), Array(0)]
0: [date: '20220301', medium: '(none)', source: '(direct)', pageviews: '3', sessions: '1', …]
1: [date: '20220301', medium: 'organic', source: 'google', pageviews: '3', sessions: '1', …]
2: [date: '20220302', medium: '(none)', source: '(direct)', pageviews: '4', sessions: '2', …]
3: [date: '20220302', medium: 'organic', source: 'bing', pageviews: '1', sessions: '1', …]
4: [date: '20220303', medium: '(none)', source: '(direct)', pageviews: '1', sessions: '1', …]
length: 5

So my best guess, check Logger print args types, and maybe Logger.log("Wrapper : ", wrapper); ?

CodePudding user response：

In App Script TableData is defined in the global scope. However the parameter TableData passed to parseBQData is in the function scope. If I try to run your script function parseBQData(TableData, request) including TableData in global scope I get TypeError: Cannot read property 'length' of undefined because TableData is undefined. You can fix this by simply:

function parseBQData(request) {

This is not a bug.

I also found this article JavaScript function parameter and scope

CodePudding user response：

Same output but much simpler

function parseBQData() {
  const iA = [["20220301", "(none)", "(direct)", "3", "1", "1"], ["20220301", "organic", "google", "3", "1", "1"], ["20220302", "(none)", "(direct)", "4", "2", "2"], ["20220302", "organic", "bing", "1", "1", "1"], ["20220303", "(none)", "(direct)", "1", "1", "1"]]
  const fields = ["date", "medium", "source", "pageviews", "sessions", "users"];
  iA.unshift(fields)
  Logger.log(JSON.stringify(iA));
}

Execution log
10:25:24 AM Notice  Execution started
10:25:25 AM Info    [["date","medium","source","pageviews","sessions","users"],["20220301","(none)","(direct)","3","1","1"],["20220301","organic","google","3","1","1"],["20220302","(none)","(direct)","4","2","2"],["20220302","organic","bing","1","1","1"],["20220303","(none)","(direct)","1","1","1"]]
10:25:26 AM Notice  Execution completed