sheetjs/demos/react/README.md

React

The xlsx.core.min.js and xlsx.full.min.js scripts are designed to be dropped into web pages with script tags:

<script src="xlsx.full.min.js"></script>

The library can also be imported directly from JSX code with:

import { read, utils, writeFileXLSX } from 'xlsx';

This demo shows a simple React component transpiled in the browser using Babel standalone library. Since there is no standard React table model, this demo settles on the array of arrays approach.

Other scripts in this demo show:

• server-rendered React component (with next.js)
• react-native deployment for iOS and android
• react-data-grid reading, modifying, and writing files

How to run

Run make react to run the browser demo for React, or run make next to run the server-rendered demo using next.js.

Internal State

The simplest state representation is an array of arrays. To avoid having the table component depend on the library, the column labels are precomputed. The state in this demo is shaped like the following object:

{
  cols: [{ name: "A", key: 0 }, { name: "B", key: 1 }, { name: "C", key: 2 }],
  data: [
    [ "id",    "name", "value" ],
    [    1, "sheetjs",    7262 ],
    [    2, "js-xlsx",    6969 ]
  ]
}

sheet_to_json and aoa_to_sheet utility functions can convert between arrays of arrays and worksheets:

/* convert from workbook to array of arrays */
var first_worksheet = workbook.Sheets[workbook.SheetNames[0]];
var data = XLSX.utils.sheet_to_json(first_worksheet, {header:1});

/* convert from array of arrays to workbook */
var worksheet = XLSX.utils.aoa_to_sheet(data);
var new_workbook = XLSX.utils.book_new();
XLSX.utils.book_append_sheet(new_workbook, worksheet, "SheetJS");

The column objects can be generated with the encode_col utility function:

function make_cols(refstr/*:string*/) {
  var o = [];
  var range = XLSX.utils.decode_range(refstr);
  for(var i = 0; i <= range.e.c; ++i) {
    o.push({name: XLSX.utils.encode_col(i), key:i});
  }
  return o;
}

React Native

The new demo uses up-to-date file I/O and file picker libraries.

Server-Rendered React Components with Next.js

The demo reads from public/sheetjs.xlsx. HTML output is generated using XLSX.utils.sheet_to_html and inserted with dangerouslySetInnerHTML:

export default function Index({html, type}) { return (
  // ...
  <div dangerouslySetInnerHTML={{ __html: html }} />
  // ...
); }

Next currently offers 3 general strategies for server-side data fetching:

"Server-Side Rendering" using getServerSideProps

/getServerSideProps reads the file on each request. The first worksheet is converted to HTML:

export async function getServerSideProps() {
  const wb = XLSX.readFile(path);
  return { props: {
    html: utils.sheet_to_html(wb.Sheets[wb.SheetNames[0]])
  }};
}

"Static Site Generation" using getStaticProps

/getServerSideProps reads the file at build time. The first worksheet is converted to HTML:

export async function getStaticProps() {
  const wb = XLSX.readFile(path);
  return { props: {
    html: utils.sheet_to_html(wb.Sheets[wb.SheetNames[0]])
  }};
}

"Static Site Generation with Dynamic Routes" using getStaticPaths

/getStaticPaths reads the file at build time and generates a list of sheets.

/sheets/[id] uses getStaticPaths to generate a path per sheet index:

export async function getStaticPaths() {
  const wb = XLSX.readFile(path);
  return {
    paths: wb.SheetNames.map((name, idx) => ({ params: { id: idx.toString()  } })),
    fallback: false
  };
}

It also uses getStaticProps for the actual HTML generation:

export async function getStaticProps(ctx) {
  const wb = XLSX.readFile(path);
  return { props: {
    html: utils.sheet_to_html(wb.Sheets[wb.SheetNames[ctx.params.id]]),
  }};
}

Additional Notes

Some additional notes can be found in NOTES.md.