ANGULAR 5 : how to export data to csv file

Update:
Here is slightly better way to do it:

1. Open up command prompt in the directory of your project.
2. Install file-saver by typing npm install --save file-saver
3. import { saveAs } from 'file-saver'; into your .ts file.
4. Here is the updated code based on the new import.

downloadFile(data: any) {
    const replacer = (key, value) => value === null ? '' : value; // specify how you want to handle null values here
    const header = Object.keys(data[0]);
    let csv = data.map(row => header.map(fieldName => JSON.stringify(row[fieldName], replacer)).join(','));
    csv.unshift(header.join(','));
    let csvArray = csv.join('\r\n');

    var blob = new Blob([csvArray], {type: 'text/csv' })
    saveAs(blob, "myFile.csv");
}

Credits to this answer for converting an object to CSV.

Here is the method to use:

downloadFile(data: any) {
  const replacer = (key, value) => (value === null ? '' : value); // specify how you want to handle null values here
  const header = Object.keys(data[0]);
  const csv = data.map((row) =>
    header
      .map((fieldName) => JSON.stringify(row[fieldName], replacer))
      .join(',')
  );
  csv.unshift(header.join(','));
  const csvArray = csv.join('\r\n');

  const a = document.createElement('a');
  const blob = new Blob([csvArray], { type: 'text/csv' });
  const url = window.URL.createObjectURL(blob);

  a.href = url;
  a.download = 'myFile.csv';
  a.click();
  window.URL.revokeObjectURL(url);
  a.remove();
}

I’ll add on later if I found a better way to do it.