snowpack-plugin-dsv

snowpack-plugin-dsv

Snowpack plugin that converts .csv and .tsv files into JavaScript modules with d3-dsv.

Requirements

This plugin requires an LTS Node version (v8.0.0+) and Snowpack v2.0.0+.

Install

Using npm:

npm install --save-dev snowpack-plugin-dsv

Usage

Create a snowpack.config.js configuration file and import the plugin to automatically detect and parse .csv, .tsv, and .psv files:

const dsv = require('snowpack-plugin-dsv');

module.exports = {
  mount: {
    public: { url: '/', static: true },
    src: { url: '/dist' },
  },
  plugins: ['snowpack-plugin-dsv'],
};

For other types of delimiters, set the delimiter property of the options object to the appropriate character. Note: You will have to set the file extension of your custom files to .dsv.

module.exports = {
  mount: { ... },
  plugins: [['snowpack-plugin-dsv', { delimiter: '~' }]],
};

If you would like to use multiple files with different delimiters, populate the delimiters array with the appropriate file extensions. Note: Make sure the second character of the custom file extension is the delimiter used in the data. Ex: If delimiting by ~, the file extension should be .~sv.

module.exports = {
  mount: { ... },
  plugins: [['snowpack-plugin-dsv', { delimiters: ['.~sv', '.%sv'] }]],
};

Practical Example

Suppose that you have a CSV (or TSV!) file which contains some information on delicious fruits:

type,count
apples,7
pears,4
bananas,5

And suppose you'd like to import that CSV as an Array within some part of your code. After adding the plugin (as shown above), you may import (or require) the CSV file directly. The import will provide an Array of Objects representing rows from the CSV file:

import fruit from './fruit.csv';

console.log(fruit);
// [
//   { type: 'apples', count: '7' },
//   { type: 'pears', count: '4' },
//   { type: 'bananas', count: '5' }
// ]

Options

delimiter

Type: string
Default: null

Indicates the delimiter that will be used by an internal dsvParse method from d3-dsv. This delimiter will be used for all files with a .dsv extension.

delimiters

Type: array
Default: null

Declares multiple file extensions and delimiters to be used during build. The extension and delimiter are indicated by a custom file extension alone - a .%sv file will be automatically delimited with %.

processRow

Type: function
Default: null

Specifies a function which processes and manipulates each row in the parsed array. The function can manipulate the passed row.

This option could be used for converting numeric string values into number values - see example below.

dsv({
  processRows: (row, id) => {
    Object.keys(row).forEach((key, id) => {
      let value = row[key].trim();
      row[key] = isNaN(Number(value)) ? value : Number(value);
    });
  },
});

Meta

LICENSE (MIT)