How can I prevent my code from proceeding until papaparse finishes?

Question

I need to papaparse to complete before it moves onto the part where it loops through the list (that papaparse needs to populate).

In my code, papaparse finishes populating the list after the loop, so my loop ends up looping over an empty list. This is what my code looks like:

const csvData=[];
papa.parse(file, {
  header: true,
  step: function(result) {
    csvData.push(result.data)
  },
  complete: function(results, file) {
    //console.log('Complete', csvData.length, 'records.'); 
    console.log(csvData);
  }
});

//loop through the list
for (var i = 0; i < csvData.length; i++){
    var jsonObj = csvData[i];
    console.log(jsonObj);
    let aimObj = jsonToAim(jsonObj);
    console.log(aimObj);
}

How can I do this? I am new to js. Thank you so much!

Answer 1

You can wrap the parse-call in a promise and await this promise:

async function processCsv (file) {
  const csvData = await new Promise((resolve) => {
    const data = [];
    papa.parse(file, {
      header: true,
      step: function (result) {
        data.push(result.data);
      },
      complete: function (results, file) {
        resolve(data);
      }
    });
  });
  
  for (let i = 0; i < csvData.length; i++) {
    // ...
  }
}