Parsing Logic for simple CSV File Upload

csvToDatatable.js

parse(csv) {
  // parse the csv file and treat each line as one item of an array
  const lines = csv.split(/\r\n|\n/);
  
  // parse the first line containing the csv column headers
  const headers = lines[0].split(',');
  
  // iterate through csv headers and transform them to column format supported by the datatable
  this.columns = headers.map((header) => {
    return { label: header, fieldName: header };
  });

  const data = [];
  
  // iterate through csv file rows and transform them to format supported by the datatable
  lines.forEach((line, i) => {
    if (i === 0) return;

    const obj = {};
    const currentline = line.split(',');

    for (let j = 0; j < headers.length; j++) {
      obj[headers[j]] = currentline[j];
    }

    data.push(obj);
  });
  
  // assign the converted csv data for the lightning datatable
  this.data = data;
}