Google Apps Script: How to remove interspersed header rows from an array? - google-apps-script

Question

I have an array of data that looks roughly like this:
header row | header row | header row | header row
project | date | LastName, FName | hours
project | date | LastName, FName | hours
project | date | LastName, FName | hours
header row | header row | header row | header row
project | date | LastName, FName | hours
project | date | LastName, FName | hours
project | date | LastName, FName | hours
I'd like to strip the header rows out of the array. I thought I'd use ArrayLib.filterByDate to do this, thinking that any rows that did not contain a valid date in my timeframe would be stripped out.
Here's the code I tried:
function removeHeaders(projectRange){
var tmpProjectRange = [];
tmpProjectRange = ArrayLib.filterByDate(projectRange, 1, new Date(2013-01-01), new Date(2015-01-01))
return tmpProjectRange;
}
I get an error: "the selected column should only contain dates". So this method appears not to be an option.
Now, I'm trying to use ArrayLib.filterByText to compare column 2 to an array of valid data:
function removeHeaders(projectRange){
var tmpEmployeeRange = [];
var tmpEmployeeList = [];
var ss = SpreadsheetApp.getActiveSpreadsheet();
var shtEmp = ss.getSheetByName("Employees");
var empLastRow = shtEmp.getLastRow();
var strRange = "A2:A" + empLastRow;
//should contain a list of all the employees:
tmpEmployeeList = shtEmp.getRange(strRange).getValues();
tmpEmployeeRange = ArrayLib.filterByText(projectRange, 2, tmpEmployeeList);
return tmpEmployeeRange;
}
But for some reason this is not working either. The only rows coming back in the tmpEmployeeRange are rows that have a name that does not have a comma (these rows have TBD rather than Last Name, First Name.) So I'm not really sure what is going on there, but I'm thinking that there has to be an easier way to do this. I guess I could just iterate through the entire thing and strip out the rows I don't want. Any other ideas?

Answer 1

If we assume that the logic of looking for rows with valid dates is correct, then it is very easy to iterate over the range and remove headers.
Here, I'm borrowing the isValidDate() function from Detecting an "invalid date" Date instance in JavaScript. I'm also keeping the first header row - you can get rid of that by removing the check for row == 0.
// Iterate over all rows, keeping the first header row and
// any row with a valid date in the second column.
function removeHeaders(projectRange){
var tmpProjectRange = [];
for (row in projectRange) {
if (row == 0 || isValidDate(projectRange[row][1])) {
tmpProjectRange.push(projectRange[row]);
}
}
return tmpProjectRange;
}
// From https://stackoverflow.com/questions/1353684
// Returns 'true' if variable d is a date object.
function isValidDate(d) {
if ( Object.prototype.toString.call(d) !== "[object Date]" )
return false;
return !isNaN(d.getTime());
}