Vizabi CSV reader

The main goal of this repo is to provide ability for Vizabi to work with CSV data.

Install

npm i vizabi-csv-reader

Usage

Usage on backend

import * as fs from 'fs';
import * as path from 'path';
import { csvReaderObject as csvReaderPlainObject } from 'vizabi-csv-reader';

global.d3 = require('d3');
global.Vizabi = require('vizabi');

const readText = (filePath, onFileRead) => {
  fs.stat(filePath, (fileErr, stat: any) => {
    if (fileErr) {
      return onFileRead(fileErr);
    }

    if (stat.code === 'ENOENT') {
      return onFileRead('No such file: ' + filePath);
    }

    fs.readFile(filePath, 'utf-8', (readErr, content) => {
      if (readErr) {
        return onFileRead(readErr);
      }

      onFileRead(null, content.toString());
    });
  });
};

const CsvReader = global.Vizabi.Reader.extend(csvReaderPlainObject);
const csvReaderObject = new CsvReader({
  path: path.resolve('path to csv file'),
  additionalTextReader: readText
});
const result = await csvReaderObject.load();

console.log(result);

Usage on frontend

<script src="node_modules/vizabi-csv-reader/dist/vizabi-csv-reader.js"></script>
<script>
  // CsvReader global variable was imported by script above
  Vizabi.Reader.extend("csv-reader", CsvReader.csvReaderObject);
  // use "csv-reader" as a Vizabi init parameter
  // .....
</script>

Get assets on backend

import * as fs from 'fs';
import { csvReaderObject as csvReaderPlainObject } from 'vizabi-csv-reader';

global.d3 = require('d3');
global.Vizabi = require('vizabi');

const readJson = (filePath, onFileRead) => {
  fs.stat(filePath, (fileErr, stat) => {
    if (fileErr) {
      return onFileRead(fileErr);
    }

    if (stat.code === 'ENOENT') {
      return onFileRead('No such file: ' + filePath);
    }

    fs.readFile(filePath, 'utf-8', (readErr, content) => {
      if (readErr) {
        return onFileRead(readErr);
      }

      try {
        onFileRead(null, JSON.parse(content.toString()));
      } catch (e) {
        onFileRead(e);
      }
    });
  });
};

const CsvReader = global.Vizabi.Reader.extend(csvReaderPlainObject);
const csvReaderObject = new CsvReader({
  assetsPath: 'path to asset file',
  additionalJsonReader: readJson
});
const result = await csvReaderObject.getAsset('path to asset');

console.log(result);

Initial parameters

• path - path to csv file that would be processed
• timeInColumns - a flag that indicates that CSV file contains data in time-in-columns format (false by default)
• lastModified - last modification date (optional)
• delimiter - CSV delimiter character (optional)
• keySize - key size (1 by default)
• hasNameColumn - an extra column that contains country name (should not be processed, optional, false by default)
• nameColumnIndex - index of nameColumn (default value is 0)
• assetsPath - path to assets JSON file (optional)
• additionalTextReader - function that should replace tenured text reading function (optional, see examples above, could be useful on frontend or testing)
• additionalJsonReader - function that should replace tenured JSON reading function (optional, see examples above, could be useful on frontend or testing)

Run tests

npm test

Build

git clone https://github.com/vizabi/vizabi-csv-reader.git
cd vizabi-csv-reader
npm i
npm run build

The result is a couple of directories: dist and lib.

dist contain two files: vizabi-csv-reader.js and vizabi-csv-reader.js.map. These files could be used on frontend: see Usage on frontend

lib (lib/index.js) - is used 'by default' (see main section of package.json) and could be used on backend (see Usage on backend)