npm package: @financial-times/sheet-reader
Description: ![Node.js CI](https://github.com/Financial-Times/dj-sheet-reader/workflows/Node.js%20CI/badge.svg)
Latest version: 2.0.1

# dj-sheet-reader

![Node.js CI](https://github.com/Financial-Times/dj-sheet-reader/workflows/Node.js%20CI/badge.svg)

> Provides the core spreadsheet processing functionality inside [Bertha](https://github.com/ft-interactive/bertha).

## What does it do?

- Fetches data from a google spreadsheet
- transforms all the cells values to types (eg booleans, numbers and arrays)
- outputs the result as an object.

[Bertha](https://github.com/ft-interactive/bertha) wraps this functionality into a service, providing also a cache and a background queue for that helps managing large spreadsheets and frequent edits.

## Installation

    $ npm install @financial-times/sheet-reader

## Usage

First, you'll need a Google API Service Account email and key. A service account reads/writes data from the Google API on behalf of a Google user/email. See the `auth` configuration options below.

```js
const SheetReader = require('@financial-times/sheet-reader')

const auth = {
	key: process.env.KEY,
	email: process.env.EMAIL,
	subject: process.env.SUBJECT,
	scopes: ['https://www.googleapis.com/auth/example.scope'],
}

const spreadsheetId = '__your__sheet__id__'
const sheetNames = ['Sheet1', '+my Optional Sheet']

const data = await SheetReader({ auth }).fetchSheet(spreadsheetId, sheetNames)

process.stdout.write(JSON.stringify(data))
```

## API

**`SheetReader(options: object):SheetReaderInstance`**

`options`:

- `auth.email`: is the Email/ID of the service account. It looks like `367017482409-ki8573gid665t1ee2m8t2omwvj3dbt2mj@developer.gserviceaccount.com`
- `auth.key`: is a key that's generated for the service account that's used authenticate with the Google API
- `auth.subject`: a Google Email account (e.g a person or email group) who is the subject of the API request and is used for authorisation. This package will be making requests to the Google API on behalf of this user and can only fetch data for a spreadsheet when the subject has read access.
- `auth.scopes`: An optional array of scopes that have been setup for the key when connecting to the Spreadsheet API in Google Cloud console . The default scopes (show below) are the most common configuation.

```
scopes: [
	'https://www.googleapis.com/auth/drive.readonly',
	'https://www.googleapis.com/auth/spreadsheets.readonly'
],
```

**`fetchSheet(spreadsheetId: string, sheetNames: string[], options: object):Promise<object>`**

- `spreadsheetId`: The ID of the Google Spreadsheet
- `sheetNames`: An array of sheet names (as they appear on the tabbed sheets)
  - It's possible for sheets to be optional
- `options`
  - reserved for future use.

**`fetchSheetWithCallback(spreadsheetId: string, sheetNames: string[], options: object, callback: Function(error, data)):SheetReaderInstance`**

Same as `fetchSheet` but uses the older callback pattern, rather than returning a promise.

```js
SheetReader({ auth }).fetchSheet(spreadsheetId, sheetNames, {}, function (error, data) {
	if (error) {
		console.error(error)
		return
	}
	process.stdout.write(JSON.stringify(data))
})
```

**`refreshAuth():void`**

Refreshes the JWT token in case it's expired.

## Licence

This software is published by the Financial Times under the [MIT licence](http://opensource.org/licenses/MIT).