Another place that Fiddler can be handy is if you are populating a sheet with data retrieved from an API. The examples use the Itunes API which will return tabular data as an array of JSON objects.
This class – Fiddler can be found in my cUseful library.
Here’s the key, and it’s also on github


Populating an API with all fields from a JSON object

To start with, we need get some data from an API, and open a sheet to dump the data to.

// lets get some data from an API
  var result = getFromItunes ("REM");
  if (!result.ok) throw result.content;
  // either create or use an existing sheet
  var ss = SpreadsheetApp.openById('1181bwZspoKoP98o4KuzO0S11IsvE59qCwiw4la9kL4o');
  var sheet = ss.getSheetByName ("itunesapi") || ss.insertSheet("itunesapi");

Now This is easy, as we can just let fiddler do its thing. It’s a one liner of 3 methods chained together 

function onOpen() {
  .addItem('Get abstract', 'getAbstract')
  .addItem('Insert abstract', 'insertAbstract')
// first of all, create a sheet with all the data, clearing it first
  new cUseful.Fiddler(sheet.clearContents())
    .setData (

And you’ll get this.


Screenshot 2017-09-25 at 13.17.49


Populating API with some fields from an API

In this case we want just a couple of fields. It’s almost exactly the same, except we filter out the columns we don’t want.

// we'll use fiddler to organize the data, and populate with selected fields from the API
  // after first clearing the sheet
  new cUseful.Fiddler(sheet.clearContents())
     // use the data from the API
    .setData (
    // but just keep a couple of the columns
    .filterColumns (function (column) {
      return ["artistName","collectionName","trackName"].indexOf(column) !== -1;
    // and write it out

Now this is the result


Screenshot 2017-09-25 at 13.23.30


Adding to an existing sheet

Now it get’s a little more complicated. Rather than specifying the fields required, this time we’ll use whatever fields are already on the sheet, and append the new data to whatever is already there.  First get some additional data to append

// Now if the columns are already set
  var result = getFromItunes ("Lady Gaga");
  if (!result.ok) throw result.content;

Now append it using these steps

  1. get the current data from the sheet into a fiddler
  2. get the column names
  3. filter the data returned from the API to reduce it to just the properties that match the column headings
  4. insert those at the end of the fiddler, and dump the values
//1 get the current data
  var fiddler = new cUseful.Fiddler(sheet);
  //2 these are the existing columns
  var columns = fiddler.getHeaders();
  //3 this is the data with the stuff we dont want filtered out
  var filteredData = (function (row) {
    return Object.keys(row).reduce (function (p,c) {
      if (columns.indexOf (c) !== -1) {
        p[c] = row[c];
      return p;
  //4 use the data from the API to insert at the end
  fiddler.insertRows (undefined ,filteredData.length , filteredData)  
  // and write it all out

The result – notice the new data added to the end, but only the columns that already existed


Screenshot 2017-09-25 at 13.29.30


The Itunes API

Here’s function used to so an Itunes search. It’s only set to get the first 50  for the purposes of this demo and will need pagination to get more. 

// generaral itunes search
  function getFromItunes (searchTerm) {
    var response = cUseful.Utils.expBackoff( function () {
      return UrlFetchApp.fetch("" + "?term=" + encodeURIComponent(searchTerm), {
    return response.getResponseCode() === 200 ?  {
      data: JSON.parse (response.getContentText()),
    } : {
For more like this see Google Apps Scripts Snippets

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