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 XLSX from 'xlsx';

This demo shows a simple React component transpiled in the browser using the 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

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

Reproducing the full project is straightforward:

# see native.sh
react-native init SheetJS
cd SheetJS
npm i -S xlsx react react-native react-native-table-component react-native-fs
cp ../react-native.js index.js
react-native link

react-native-table-component draws the data table. react-native-fs reads and write files on devices. The app will prompt before reading and after writing data. The printed location will be:

• android: path in the device filesystem
• iOS simulator: local path to file
• iOS device: a path accessible from iTunes App Documents view

react-native-fs supports "ascii" encoding for readFile and writeFile. In practice, that encoding uses binary strings compatible with "binary" type:

import { writeFile, readFile } from 'react-native-fs';

/* read a workbook */
readFile(file, 'ascii').then((res) => {
  const workbook = XLSX.read(res, {type:'binary'});
  /* DO SOMETHING WITH workbook HERE */
});

/* write a workbook */
const wbout = XLSX.write(wb, {type:'binary', bookType:"xlsx"});
writeFile(file, wbout, 'ascii').then((r)=>{/* :) */}).catch((e)=>{/* :( */});

Note: for real app deployments, the UIFileSharingEnabled flag must be manually set in the iOS project Info.plist file.

To run the React Native demo, run either make ios or make android while connected to a device or emulator.

Server-Rendered React Components with Next.js

The demo uses the same component code as the in-browser version, but the build step adds a small header that imports the library. The import is not needed in deployments that use script tags to include the library.

Additional Notes

Some additional notes can be found in NOTES.md.