How to use papaparse - 10 common examples

a.meta.fields;
    b.name;
  }
}): PapaParse$ParseResult);

var flat: Array = [{a: 1, b: 1, c: 1}];
(Papa.unparse(flat): string);

var nested: Array> = [[1, 2, 3], [4, 5, 6]];
(Papa.unparse(nested): string);

var explicit: PapaParse$UnparseObject = {
  fields: ['One', 'Two'],
  data: '1,2',
};
(Papa.unparse(explicit): string);

var explicitAnyData: PapaParse$UnparseObject = {
  fields: ['One', 'Two'],
  data: [1, 2]
};
(Papa.unparse(explicitAnyData): string);

// $ExpectError
var explicitInvalidData: PapaParse$UnparseObject = {
  fields: ['One', 'Two'],
  data: 1
};
(Papa.unparse(explicitInvalidData): string);

// $ExpectError
var explicitInvalidFields: PapaParse$UnparseObject = {

};
(Papa.unparse(explicitAnyData): string);

// $ExpectError
var explicitInvalidData: PapaParse$UnparseObject = {
  fields: ['One', 'Two'],
  data: 1
};
(Papa.unparse(explicitInvalidData): string);

// $ExpectError
var explicitInvalidFields: PapaParse$UnparseObject = {
  fields: 'One,Two',
  data: '1,2'
};
(Papa.unparse(explicitInvalidFields): string);

Papa.unparse({
  fields: ["3"],
  data: ["3"]
});

Papa.unparse({
  fields: ["3"],
  data: ["3"]
}, {
  quotes: true
});

Papa.SCRIPT_PATH;
Papa.LocalChunkSize;

data: '1,2',
};
(Papa.unparse(explicit): string);

var explicitAnyData: PapaParse$UnparseObject = {
  fields: ['One', 'Two'],
  data: [1, 2]
};
(Papa.unparse(explicitAnyData): string);

// $ExpectError
var explicitInvalidData: PapaParse$UnparseObject = {
  fields: ['One', 'Two'],
  data: 1
};
(Papa.unparse(explicitInvalidData): string);

// $ExpectError
var explicitInvalidFields: PapaParse$UnparseObject = {
  fields: 'One,Two',
  data: '1,2'
};
(Papa.unparse(explicitInvalidFields): string);

Papa.unparse({
  fields: ["3"],
  data: ["3"]
});

Papa.unparse({
  fields: ["3"],
  data: ["3"]

return new Promise((resolve, reject) => {
    Papa.parse(file, {
      skipEmptyLines: true,
      complete: ({data}) => {
        if (data.length === 0) {
          NylasEnv.showErrorDialog(
            `The csv file you are trying to import contains no rows. Please select another file.`
          );
          resolve(null)
          return;
        }

        // If a cell in the first row contains a valid email address, assume that
        // the table has no headers. We need row[0] to be field names, so make some up!
        const emailRegexp = RegExpUtils.emailRegex();
        const emailInFirstRow = data[0].find((val) => emailRegexp.test(val));
        if (emailInFirstRow) {
          const headers = data[0].map((val, idx) => {

// Move file because of UTF8 issues with Jekyll
  var fileToMove = './dist/_data/users.json'
  var filePath = './dist/js/data/users.json'
  if (fs.existsSync(fileToMove)) {
    fs.removeSync(filePath)
    fs.moveSync(fileToMove, filePath)
  }

  var users = fs.readJsonSync(filePath)

  // Shuffle the users
  users = utils.shuffleArray(users)

  // Save to CSV
  fs.outputFileSync('./dist/_data/users.csv', Papa.unparse(users))

  console.log('Finished processing ' + users.length + ' users.')
}

create() {
        var csvString = `,2,3
4,5,6
7,8,9`;
        var data = Papa.parse(csvString, {
            dynamicTyping: true
        });
        console.log(data);  // a 3x3 array

        csvString = `name,hp,mp
4,5,6
7,8,9`;
        data = Papa.parse(csvString, {
            dynamicTyping: true,
            header: true
        });
        console.log(data);  // an object array with 2 rows
    }

create() {
        var csvString = `,2,3
4,5,6
7,8,9`;
        var data = Papa.parse(csvString, {
            dynamicTyping: true
        });
        console.log(data);  // a 3x3 array

        csvString = `name,hp,mp
4,5,6
7,8,9`;
        data = Papa.parse(csvString, {
            dynamicTyping: true,
            header: true
        });
        console.log(data);  // an object array with 2 rows
    }

create() {
        var csvString = `name,hp,mp
Rex,100,20
Alice,300,40`;

        var csvTable = Papa.parse(csvString, {
            dynamicTyping: true,
            header: true
        }).data;

        // Create the database
        var db = new loki();

        // Create a collection
        var children = db.addCollection('children');

        // insert csv-table
        children.insert(csvTable);

        var result = children.chain().data();
        console.log(result);
    }

readCSV(text: string): SeriesData[] {
    this.data = [this.series];

    const papacfg = {
      ...this.config,
      dynamicTyping: false,
      skipEmptyLines: true,
      comments: false, // Keep comment lines
      step: this.step,
    } as ParseConfig;

    Papa.parse(text, papacfg);
    return this.data;
  }
}

export const loadCsvFileWithoutWorker = (path, onComplete) => {
  const batchId = Date.now();
  // https://www.papaparse.com/docs#config
  parse(path, {
    delimiter: ',',
    download: true,
    dynamicTyping: true,
    // TODO: header: true lead to large memory consumption
    header: true,
    newline: '',
    quotes: false,
    quoteChar: '"',
    skipEmptyLines: true,
    complete: results => {
      const {
        data,
        meta: {fields},
      } = results;
      onComplete({data, fields, batchId});
    },