Class DataCollector<T>

constructor

• new DataCollector<T extends Data>(
      filename?: string,
      stringifier?: DataStringifier,
  ): DataCollector<T>

  Built-in supports for CSV and JSON formats. You can extend this by DataCollector.stringifiers or provide stringifier parameter.

  Type Parameters

  • T extends Data

  Parameters

  • filename: string = ...

    Default is data-${Date.now()}.csv

  • Optionalstringifier: DataStringifier

    An instance of DataStringifier. If not provided, a default stringifier will be used based on the file extension.

  Returns DataCollector<T>

Static Readonlystringifiers

// add support for Markdown files, whose extension is 'md'
DataCollector.stringifiers['md'] = class MarkdownStringifier extends (
  DataStringifier
) {
  transform(data) {
    // write transform logic here
    return '';
  }
  final() {
    // write final logic here
    return '';
  }
};

using dc = app.collector('data.md'); // now you can save to Markdown file
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Readonlyrows

Readonlystringifier

Readonlyfilename

add

• add(row: T): string

  Add a data row

  You need to provide primitive value only.

  Parameters

  • row: T

  Returns string

  Example

  // convert array
  dc.add({ array: [0, 1, 2] }); // ❌
  dc.add({ array: [0, 1, 2].join(',') }); // ✔️
  
  // convert object
  dc.add({ object: { a: 1, b: 2 } }); // ❌
  dc.add({ object: JSON.stringify({ a: 1, b: 2 }) }); // ✔️
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save

• save(): void

  Write data to disk

  In most cases, you don't need to call this method manually. It will be called automatically when the collector is disposed.

  It is one-time, so multiple calls will be ignored.

  Returns void

  Example

  dc.save(); // ✔️ the first call is successful
  dc.save(); // ❌ the subsequent calls will be ignored
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download

• download(suffix?: string): void

  Download data to disk

  Parameters

  • suffix: string = ''

  Returns void