How to read JSON response body inside Apps Script

I want to import data inside Google Sheets from the Snapchat API using Apps Script.

So far I have the following code:

function readData() {

var accesstoken = "TOKEN"    
var sheet = SpreadsheetApp.getActiveSheet() 
 var url = "https://adsapi.snapchat.com/v1/campaigns/e431cbcd-2281-49fe-8d05-b26c87660eb5/stats"

 var response = UrlFetchApp.fetch(url, {
       headers: {
           "Authorization": "Bearer " + accesstoken
       }
   });
 var data = JSON.parse(response.getContentText());
 var campaigndata = []
 campaigndata.push(data.total_stats)

 var campaign = []
 campaign.push(campaigndata)

 var targetrange = sheet.getRange('B2:B')

 targetrange.setValue(campaign)

}

As per the Snapchat documentation (https://marketingapi.snapchat.com/docs/#request-response-pattern), I would like to get the number of impressions from that response body :

{
  "request_status": "success",
  "request_id": "57ad1ad600076e58fa35e192",
  "total_stats": [
    {
      "sub_request_status": "success",
      "total_stat": {
        "id": "7057e31f-b908-4bc7-85dd-88169f53e08d",
        "type": "CAMPAIGN",
        "granularity": "TOTAL",
        "stats": {
          "impressions": 0,
          "swipes": 0,
          "spend": 0,
          "quartile_1": 0,
          "quartile_2": 0,
          "quartile_3": 0,
          "view_completion": 0,
          "screen_time_millis": 0
        }
      }
    }
  ]
}

In my array I am pushing:

campaigndata.push(data.total_stats)

and it is working, but as soon as I try looking for the impressions data by writing:

campaigndata.push(data.total_stats.total_stat.stats.impressions)

As per the response body, it is not working. And I am receiving the following error:

TypeError: Cannot read properties of undefined (reading 'stats')

The error occurs on line 38, where the abovementioned line is written.

How can I retrieve specific data from the response body ?

Thank you for your help.

Solution

When you want to retrieve 0 of "impressions": 0, from the following JSON object,

{
  "request_status": "success",
  "request_id": "57ad1ad600076e58fa35e192",
  "total_stats": [
    {
      "sub_request_status": "success",
      "total_stat": {
        "id": "7057e31f-b908-4bc7-85dd-88169f53e08d",
        "type": "CAMPAIGN",
        "granularity": "TOTAL",
        "stats": {
          "impressions": 0,
          "swipes": 0,
          "spend": 0,
          "quartile_1": 0,
          "quartile_2": 0,
          "quartile_3": 0,
          "view_completion": 0,
          "screen_time_millis": 0
        }
      }
    }
  ]
}

and, when this JSON object is data in your showing script, how about the following script?

var res = data.total_stats[0].total_stat.stats.impressions;
console.log(res)

By this script, the value of "impressions": 0, from the above JSON object. In this case, total_stats is an array. Please be careful about this.

If you want to put this value to the cell "B2", how about the following modification?

From:

var data = JSON.parse(response.getContentText());
var campaigndata = []
campaigndata.push(data.total_stats)

var campaign = []
campaign.push(campaigndata)

var targetrange = sheet.getRange('B2:B')

targetrange.setValue(campaign)

To:

var data = JSON.parse(response.getContentText());
var res = data.total_stats[0].total_stat.stats.impressions;
var targetrange = sheet.getRange('B2');
targetrange.setValue(res);