Log Missing Column in Destination Spreadsheet - google-apps-script

Question

I have the code below which allows me to update the existing spreadsheet (much like an matrix lookup). And what I am doing right now is to include a error log which will be updated in another sheet, this includes Missing data in Column A in Destination Spreadsheet and Missing Column in Destination Spreadsheet. I have worked with Missing data in Column A, my problem was the Missing Column, cause instead of the column name (found in the row 1) the result shows the column index:
code:
function updateShadowSKU() {
var source = SpreadsheetApp.getActive().getSheetByName('Sheet1');
var dest = SpreadsheetApp.openById('179PCrIWe1mvbbzOi9ySEHxzBlFaXpCB2i0wHlYVE2vg').getSheetByName('Sheet1');
var destRange = dest.getDataRange();
var destValues = destRange.getValues();
var destHeaders = destValues[0];
var destIds = destValues.map(e => e[0]);
var values = source.getDataRange().getValues().map(e => e.filter((f, i) => !i || i > 10));
var colMap = values[0].map(e => destHeaders.indexOf(e));
Logger.log(colMap);
values = values.map((e, i, arr) => e.map((f, j) => [e[0], colMap[j], f, values[0][j], i, j])).flat().filter(e => e[0] && e[1] && e[2] && e[3] && e[4] && e[5]);
Logger.log(values);
// Initialize an array to store log entries
var logEntries = [];
// Check for missing SKUs
values.forEach(function(e) {
if (!destIds.includes(e[0])) {
logEntries.push(["Missing SKU", e[0], e[3]]);
}
});
// Check for missing column headers
colMap.forEach(function(e, i) {
if (e == -1) {
var index = destHeaders.indexOf(values[0][i]);
colMap[i] = index;
if (index == -1) {
logEntries.push(["Missing column header", values[0][e], ""]);
}
}
});
if (!values.length) {
logEntries.push(["No changes to make", "", ""]);
} else {
values = values.map(e => [destIds.indexOf(e[0]), e[1], e[2]]);
Logger.log(values.length + ' changes to make');
Logger.log(values);
values.forEach(function(e) {
try {
destValues[e[0]][e[1]] = e[2];
} catch (err) {}
});
destRange.setValues(destValues);
}
// Write log entries to the 'Shadow Log' sheet in the destination spreadsheet
if (logEntries.length > 0) {
var logSheet = SpreadsheetApp.openById('179PCrIWe1mvbbzOi9ySEHxzBlFaXpCB2i0wHlYVE2vg').getSheetByName("Shadow Log");
if (logSheet == null) {
logSheet = SpreadsheetApp.openById('179PCrIWe1mvbbzOi9ySEHxzBlFaXpCB2i0wHlYVE2vg').insertSheet("Shadow Log");
}
logSheet.clear();
logSheet.getRange(1, 1, logEntries.length, 3).setValues(logEntries);
}
}
the code block for getting the missing data in Column A destination spreadsheet works fine, but what I am having a hard time is getting the column name. The code block below shows only the column index instead of the comlumn title/header:
// Check for missing column headers
colMap.forEach(function(e, i) {
if (e == -1) {
var index = destHeaders.indexOf(values[0][i]);
colMap[i] = index;
if (index == -1) {
logEntries.push(["Missing column header", values[0][e], ""]);
}
}
});
sample sheets:
source: https://docs.google.com/spreadsheets/d/1zGqiYocUmSBRDPKRqI3iI3nIf7w3b9C7ykT-QffBROA/edit#gid=0
destination: https://docs.google.com/spreadsheets/d/1PjOvhscblzPxaBnJi1Q5oB6iCAt9_emljUR6vlAfIA0/edit#gid=0
example:
source data:
| SKU | walmart1 | amazon 2 | ebay1 |
|============|==============|==============|===========|
| SKUitem1 | SKUwm1 | | SKUebay1 |
| SKUitem2 | | | SKUitem5 |
| SKUitem3 | SKUwmi1 | | |
destination:
| items | **walmart2** | **amazon 1** | ebay1 |
|============|==============|==============|===========|
| SKUitem1 | SKUwm1 | | SKUebay1 |
|**SKUitem5**| | | |
| SKUitem3 | | | |
desired result:
in this scenario the 'Shadow Log' sheet should result into
| Missing SKU | SKUitem2 |
| Missing Column | walmart1 |
missing SKU - cause there were an update from the source but unable to find it in the destination
missing column - cause there were an update on that column but unable to find that column
you will also see that there is a mismatch column amazon 2 --> amazon 1, but you will see nothing in the desired results, it is because there's no new data to be updated.
I hope this clears things out, please don't hesitate to ask me

Answer 1

Check and Fix the Index when Accessing Desired Data
I noticed that when you tried to access the data from values, you used [e] as the index which will lead to an undefined value since [e] will always be -1 in your case and there is no -1 index in an arrays.
Also, when using the forEach method, the first variable (e in your case) will be the value to be processed while the second variable will be the index value (i in your case). Hence, you should use [i] when accessing data using loops.
With all that, I added a sourceCol variable to store all wanted column headers from the source.
You may change the range if you should add more columns. I changed values[0][e] to sourceCol[0][i] to access the wanted column header.
The new code should look like this: (I added comments for further guidance)
function updateShadowSKU() {
var source = SpreadsheetApp.getActive().getSheetByName('Sheet1');
var dest = SpreadsheetApp.openById('Destination Sheet ID').getSheetByName('Sheet1');
var destRange = dest.getDataRange();
var destValues = destRange.getValues();
var destHeaders = destValues[0];
var destIds = destValues.map(e => e[0]);
var values = source.getDataRange().getValues().map(e => e.filter((f, i) => !i || i > 10));
//-----------------------------------------------------------------------------------------------
//added sourceCol variable to specifically get the array of all Column Headers from the Source
var sourceCol = source.getDataRange().getValues().map(e => e.filter((f, i) => i >= 3 && i <= 17));
var colMap = sourceCol[0].map(e => destHeaders.indexOf(e));
//-----------------------------------------------------------------------------------------------
values = values.map((e, i, arr) => e.map((f, j) => [e[0], colMap[j], f, values[0][j], i, j])).flat().filter(e => e[0] && e[1] && e[2] && e[3] && e[4] && e[5]);
// Initialize an array to store log entries
var logEntries = [];
// Check for missing SKUs
values.forEach(function (e) {
if (!destIds.includes(e[0])) {
logEntries.push(["Missing SKU", e[0], e[3]]);
}
});
// Check for missing column headers
colMap.forEach(function (e, i) {
if (e == -1) {
//--------------------------------------------------------------
//change values[0][e] to sourceCol[0][i]
logEntries.push(["Missing column header", sourceCol[0][i], ""]);
//--------------------------------------------------------------
}
});
if (!values.length) {
logEntries.push(["No changes to make", "", ""]);
} else {
values = values.map(e => [destIds.indexOf(e[0]), e[1], e[2]]);
Logger.log(values.length + ' changes to make');
Logger.log(values);
values.forEach(function (e) {
try {
destValues[e[0]][e[1]] = e[2];
} catch (err) { }
});
destRange.setValues(destValues);
}
// Write log entries to the 'Shadow Log' sheet in the destination spreadsheet
// Added an else statement to clear the 'Shadow Log` when the log is empty.
var logSheet = SpreadsheetApp.openById('Destination Sheet ID').getSheetByName("Shadow Log");
if (logEntries.length > 0) {
if (logSheet == null) {
logSheet = SpreadsheetApp.openById('Destination Sheet ID').insertSheet("Shadow Log");
}
logSheet.clear();
logSheet.getRange(1, 1, logEntries.length, 3).setValues(logEntries);
}
else {
logSheet.clear();
}
}
Output
In testing the code, I deleted 5 column headers (as seen below):
When I ran the code with the modification, I got the following output:
References
forEach
Accessing Arrays