Looping through wsproxy retrieve results with SSJS

Question

I'm trying to loop through all folders found in the parent folder and show the folder names. This is what I have so far but it doesn't work (I just get an error page)

<script runat="server">
  Platform.Load("core", "1.1.5");
var parentFolderID = 327786;
var prox = new Script.Util.WSProxy();
var cols = ["Name", "ContentType", "ID", "CustomerKey"];
var filter = {
  LeftOperand: {
    Property: "ParentFolder.ID",
    SimpleOperator: "equals",
    Value: parentFolderID
  },
  LogicalOperator: "AND",
  RightOperand: {
    Property: "ContentType",
    SimpleOperator: "equals",
    Value: 'dataextension'
  }
};
var data = prox.retrieve("DataFolder", cols, filter);
 
  
  for (var i=0; i< data.length; i++) {
      Write(data.Results[i].Name+"<br>");
  };

</script>

If I don't write it in a loop and write it out line by line like the code below, the Folder Name is displayed and this is the only way I can get it to work so far:

Write(data.Results[0].Name);

this however isn't going to work for the scenario that I want, which is looping through all subfolders and displaying the name

I also know that there ARE results that exist because this is the example output

{
  "Status": "OK",
  "RequestID": "4ab563b5-9195-4568-905c-cab6d963c685",
  "Results": [{
    "ParentFolder": null,
    "Name": "2020",
    "Description": null,
    "ContentType": "dataextension",
    "IsActive": false,
    "IsEditable": false,
    "AllowChildren": false,
    "Client": null,
    "PartnerKey": null,
    "PartnerProperties": null,
    "CreatedDate": "0001-01-01T00:00:00.000",
    "ModifiedDate": null,
    "ID": 328162,
    "ObjectID": null,
    "CustomerKey": "",
    "Owner": null,
    "CorrelationID": null,
    "ObjectState": null,
    "IsPlatformObject": false
  }, {
    "ID": 342627,
    "ContentType": "dataextension",
    "Name": "2021",
    "CustomerKey": "",
    "ParentFolder": null,
    "Description": null,
    "IsActive": false,
    "IsEditable": false,
    "AllowChildren": false,
    "Client": null,
    "PartnerKey": null,
    "PartnerProperties": null,
    "CreatedDate": "0001-01-01T00:00:00.000",
    "ModifiedDate": null,
    "ObjectID": null,
    "Owner": null,
    "CorrelationID": null,
    "ObjectState": null,
    "IsPlatformObject": false
  }],
  "HasMoreRows": false
}

And when I wrap the loop with a try/catch this is the message I get. Note that the "2020" and "2021" are the folder names that I wanted to grab

2020
2021
{"message":"\"i[i]\" is not defined","description":"Jint.JintException: \"i[i]\" is not defined - from Jint\r\n\r\n"}

Answer 1

You need to loop through the Results array of the object returned by your retrieve call. The object itself, "data", isn't an array:

var data = prox.retrieve("DataFolder", cols, filter);

for (var i=0; i< data.Results.length; i++) {
      Write(data.Results[i].Name+"<br>");
};

Alternatively, you could define your "data" variable the Results array:

var data = prox.retrieve("DataFolder", cols, filter).Results;

for (var i=0; i< data.length; i++) {
      Write(data[i].Name+"<br>");
};