Skip to main content

iOS and Android Apps

Many mobile app frameworks mix JavaScript / CSS / HTML5 concepts with native extensions and libraries to create a hybrid development experience. Developers well-versed in web technologies can now build actual mobile applications that run on iOS and Android!

danger

The ecosystem has broken backwards-compatibility many times!

iOS and Android, as well as the underlying JavaScript frameworks, make breaking changes regularly. The demos were tested against emulators / real devices at some point in time. A framework or OS change can render the demos inoperable.

Each demo section will mention test dates and platform versions.

The "JavaScript Engines" section includes samples for JavaScript engines used in the mobile app frameworks. SheetJS libraries have been tested in the relevant engines and should "just work" with some caveats.

readFile and writeFile

XLSX.readFile and XLSX.writeFile do not work in mobile apps! The demos include platform-specific details for fetching file data for XLSX.read and writing file data generated by XLSX.write.

Some platforms provide this functionality as part of the standard library. Other platforms, including React Native, do not. When the platform does not provide, usually there are third-party modules to provide needed functionality.

MacOS is required for the iOS demos. The Android demos were tested on MacOS.

React Native

note

This demo was tested on an Intel Mac on 2022 August 14 with RN 0.67.2.

The iOS simulator runs iOS 15.5 on an iPhone 13.

The Android simulator runs Android 12 (S) Platform 31 on a Pixel 5.

danger

React Native does not provide a native file picker or a method for reading and writing data from documents on the devices. A third-party library must be used.

Since React Native internals change between releases, libraries may only work with specific versions of React Native. Project documentation should be consulted before picking a library.

The following table lists tested file plugins. "OS" lists tested platforms ("A" for Android and "I" for iOS). "Copy" indicates whether an explicit copy is needed (file picker copies to cache directory and file plugin reads cache).

File system PluginFile Picker PluginOSCopy
react-native-file-accessreact-native-document-pickerAI
react-native-blob-utilreact-native-document-pickerAIYES
rn-fetch-blobreact-native-document-pickerAIYES
react-native-fsreact-native-document-pickerAIYES
expo-file-systemexpo-document-picker IYES

RN File Picker

The following libraries have been tested:

react-native-document-picker

Selecting a file (click to show)

When a copy is not needed:

import { pickSingle } from 'react-native-document-picker';

const f = await pickSingle({allowMultiSelection: false, mode: "open" });
const path = f.uri; // this path can be read by RN file plugins

When a copy is needed:

import { pickSingle } from 'react-native-document-picker';

const f = await pickSingle({allowMultiSelection: false, copyTo: "cachesDirectory", mode: "open" });
const path = f.fileCopyUri; // this path can be read by RN file plugins

expo-document-picker

Selecting a file (click to show)

When using DocumentPicker.getDocumentAsync, enable copyToCacheDirectory:

import * as DocumentPicker from 'expo-document-picker';

const result = await DocumentPicker.getDocumentAsync({
copyToCacheDirectory: true,
type: ['application/vnd.ms-excel', 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet']
});
const path = result.uri;

RN File Plugins

The following libraries have been tested:

react-native-blob-util and rn-fetch-blob

Historical Context

The react-native-fetch-blob project was archived in 2019. At the time, there were a number of project forks. The maintainers blessed the rn-fetch-blob fork as the spiritual successor.

react-native-blob-util is an active fork of rn-fetch-blob

On the day that this demo was tested (2022 August 14), both rn-fetch-blob and react-native-blob-util worked with the tested iOS and Android SDK versions. The APIs are identical for the purposes of working with files.

The ascii type returns an array of numbers corresponding to the raw bytes. A Uint8Array from the data is compatible with the buffer type.

Reading and Writing snippets (click to show)

The snippets use rn-fetch-blob. To use react-native-blob-util, change the import statements to load the module.

Reading Data

import * as XLSX from "xlsx";
import RNFetchBlob from 'rn-fetch-blob'; // or react-native-blob-util
const { readFile } = RNFetchBlob.fs;

const res = await readFile(path, 'ascii');
const wb = XLSX.read(new Uint8Array(res), {type:'buffer'});
caution

On iOS, the URI from react-native-document-picker must be massaged:

import { pickSingle } from 'react-native-document-picker';
import RNFetchBlob from 'rn-fetch-blob'; // or react-native-blob-util
const { readFile, dirs: { DocumentDir } } = RNFetchBlob.fs;

const f = await pickSingle({
// Instruct the document picker to copy file to Documents directory
copyTo: "documentDirectory",
allowMultiSelection: false, mode: "open" });
// `f.uri` is the original path and `f.fileCopyUri` is the path to the copy
let path = f.fileCopyUri;
// iOS workaround
if (Platform.OS === 'ios') path = path.replace(/^.*\/Documents\//, DDP + "/");

const res = await readFile(path, 'ascii');

Writing Data

import * as XLSX from "xlsx";
import RNFetchBlob from 'rn-fetch-blob'; // or react-native-blob-util
const { writeFile, readFile, dirs:{ DocumentDir } } = RNFetchBlob.fs;

const wbout = XLSX.write(wb, {type:'buffer', bookType:"xlsx"});
const file = DocumentDir + "/sheetjsw.xlsx";
const res = await writeFile(file, Array.from(wbout), 'ascii');

react-native-file-access

The base64 encoding returns strings compatible with the base64 type:

Reading and Writing snippets (click to show)

Reading Data

import * as XLSX from "xlsx";
import { FileSystem } from "react-native-file-access";

const b64 = await FileSystem.readFile(path, "base64");
/* b64 is a Base64 string */
const workbook = XLSX.read(b64, {type: "base64"});

Writing Data

import * as XLSX from "xlsx";
import { Dirs, FileSystem } from "react-native-file-access";
const DDP = Dirs.DocumentDir + "/";

const b64 = XLSX.write(workbook, {type:'base64', bookType:"xlsx"});
/* b64 is a Base64 string */
await FileSystem.writeFile(DDP + "sheetjs.xlsx", b64, "base64");

react-native-fs

The ascii encoding returns binary strings compatible with the binary type:

Reading and Writing snippets (click to show)

Reading Data

import * as XLSX from "xlsx";
import { readFile } from "react-native-fs";

const bstr = await readFile(path, "ascii");
/* bstr is a binary string */
const workbook = XLSX.read(bstr, {type: "binary"});

Writing Data

import * as XLSX from "xlsx";
import { writeFile, DocumentDirectoryPath } from "react-native-fs";

const bstr = XLSX.write(workbook, {type:'binary', bookType:"xlsx"});
/* bstr is a binary string */
await writeFile(DocumentDirectoryPath + "/sheetjs.xlsx", bstr, "ascii");

expo-file-system

caution

Some Expo APIs return URI that cannot be read with expo-file-system. This will manifest as an error:

Unsupported scheme for location '...'

The expo-document-picker snippet makes a local copy.

The EncodingType.Base64 encoding is compatible with base64 type.

Reading and Writing snippets (click to show)

Reading Data

Calling FileSystem.readAsStringAsync with FileSystem.EncodingType.Base64 encoding returns a promise resolving to a string compatible with base64 type:

import * as XLSX from "xlsx";
import * as FileSystem from 'expo-file-system';

const b64 = await FileSystem.readAsStringAsync(uri, { encoding: FileSystem.EncodingType.Base64 });
const workbook = XLSX.read(b64, { type: "base64" });

Writing Data

The FileSystem.EncodingType.Base64 encoding accepts Base64 strings:

import * as XLSX from "xlsx";
import * as FileSystem from 'expo-file-system';

const b64 = XLSX.write(workbook, {type:'base64', bookType:"xlsx"});
/* b64 is a Base64 string */
await FileSystem.writeAsStringAsync(FileSystem.documentDirectory + "sheetjs.xlsx", b64, { encoding: FileSystem.EncodingType.Base64 });

Demo

danger

There are many moving parts and pitfalls with React Native apps. It is strongly recommended to follow the official React Native tutorials for iOS and Android before approaching this demo. Details like creating an Android Virtual Device are not covered here.

Complete Example (click to show)

This example tries to separate the library-specific functions.

0) Follow the official React Native CLI Guide!

Development Environment Guide: http://reactnative.dev/docs/environment-setup

Follow the instructions for iOS and for Android. They will cover installation and system configuration. By the end, you should be able to run the sample app in the Android and the iOS simulators.

1) Create project:

npx react-native init SheetJSRN --version="0.67.2"

2) Install shared dependencies:

cd SheetJSRN
curl -LO http://oss.sheetjs.com/assets/img/logo.png
npm i -S https://cdn.sheetjs.com/xlsx-latest/xlsx-latest.tgz
npm i -S react-native-table-component react-native-document-picker

Refresh iOS project by running pod install from the ios subfolder:

cd ios
pod install
cd ..

3) Download index.js and replace:

curl -LO https://docs.sheetjs.com/mobile/index.js

Start the iOS emulator:

npx react-native run-ios

You should see the skeleton app:

React Native iOS App

4) Pick a filesystem library for integration:

Install react-native-blob-util dependency:

npm i -S react-native-blob-util

Add the highlighted lines to index.js:

index.js
import { Table, Row, Rows, TableWrapper } from 'react-native-table-component';

import { read, write } from 'xlsx';
import { pickSingle } from 'react-native-document-picker';
import { Platform } from 'react-native';
import RNFetchBlob from 'react-native-blob-util';

async function pickAndParse() {
/* rn-fetch-blob / react-native-blob-util need a copy */
const f = await pickSingle({allowMultiSelection: false, copyTo: "documentDirectory", mode: "open" });
let path = f.fileCopyUri;
if (Platform.OS === 'ios') path = path.replace(/^.*\/Documents\//, RNFetchBlob.fs.dirs.DocumentDir + "/");
const res = await RNFetchBlob.fs.readFile(path, 'ascii');
return read(new Uint8Array(res), {type: 'buffer'});
}

async function writeWorkbook(wb) {
const wbout = write(wb, {type:'buffer', bookType:"xlsx"});
const file = RNFetchBlob.fs.dirs.DocumentDir + "/sheetjsw.xlsx";
await RNFetchBlob.fs.writeFile(file, Array.from(wbout), 'ascii');
return file;
}

const make_width = ws => {

5) Refresh the app:

cd ios
pod install
cd ..

Once refreshed, the development process must be restarted:

npx react-native run-ios

iOS Testing

The app can be tested with the following sequence in the simulator:

  • Download https://sheetjs.com/pres.numbers
  • In the simulator, click the Home icon to return to the home screen
  • Click on the "Files" icon
  • Click and drag pres.numbers from a Finder window into the simulator.

save file iOS

  • Make sure "On My iPhone" is highlighted and select "Save"
  • Click the Home icon again then select the SheetJSRN app
  • Click "Import data" and select pres:

pick file iOS

Once selected, the screen should refresh with new contents:

read file iOS

  • Click "Export data". You will see a popup with a location:

write file iOS

  • Find the file and verify the contents are correct:
find ~/Library/Developer/CoreSimulator -name sheetjsw.xlsx |
while read x; do echo "$x"; npx xlsx-cli "$x"; done

Once testing is complete, stop the simulator and the development process.

Android Testing

There are no Android-specific steps. Emulator can be started with:

npx react-native run-android

React Native Android App

The app can be tested with the following sequence in the simulator:

pick file Android

Once selected, the screen should refresh with new contents:

read file Android

  • Click "Export data". You will see a popup with a location:

write file Android

  • Pull the file from the simulator and verify the contents:
adb exec-out run-as com.sheetjsrn cat files/sheetjsw.xlsx > /tmp/sheetjsw.xlsx
npx xlsx-cli /tmp/sheetjsw.xlsx

NativeScript

note

This demo was tested on an Intel Mac on 2022 August 10. NativeScript version (as verified with ns --version) is 8.3.2. The iOS simulator runs iOS 15.5 on an iPhone SE 3rd generation.

Binary Data issues

NativeScript will not safely transmit binary or UTF-8 strings. XLSB, NUMBERS, XLSX, XLS, ODS, SYLK, and DBF exports are known to be mangled.

This is a known NativeScript bug

This demo will focus on ASCII CSV files. Once the bug is resolved, XLSX and other formats will be supported.

The @nativescript/core/file-system package provides classes for file access.

Integration Details

Reading and writing data require a file handle. The following snippet searches typical document folders for a specified filename:

import { File, Folder, knownFolders, path } from '@nativescript/core/file-system';

function get_handle_for_filename(filename: string): File {
const target: Folder = knownFolders.documents() || knownFolders.ios.sharedPublic();
const url: string = path.normalize(target.path + "///" + filename);
return File.fromPath(url);
}

The encoding ISO_8859_1 spiritually resembles the "binary" SheetJS type

Reading data

File#readText(encoding.ISO_8859_1) returns strings compatible with "binary"

/* get binary string */
const bstr: string = await file.readText(encoding.ISO_8859_1);

/* read workbook */
const wb = read(bstr, { type: "binary" });

Writing data

File#writeText with the ISO_8859_1 encoding accepts "binary" strings with the caveat listed in the warning at the top of this section:

/* generate binary string */
const bstr: string = write(wb, { bookType: 'csv', type: 'binary' });

/* attempt to save binary string to file */
await file.writeText(bstr, encoding.ISO_8859_1);

Demo

The demo builds off of the NativeScript + Angular example. Familiarity with Angular and TypeScript is assumed.

Complete Example (click to show)

0) Follow the official Environment Setup instructions (tested with "MacOS + iOS")

1) Create a skeleton NativeScript + Angular app:

ns create SheetJSNS --ng

2) Launch the app in the iOS simulator to verify that the demo built properly:

cd SheetJSNS
ns run ios

(this may take a while)

Once the simulator launches and the test app is displayed, end the script by selecting the terminal and entering the key sequence CTRL + C

3) From the project folder, install the library:

npm i --save https://cdn.sheetjs.com/xlsx-latest/xlsx-latest.tgz

4) To confirm the library was loaded, change the title to show the version. The differences are highlighted.

src/app/item/items.component.ts imports the version string to the component:

src/app/item/items.component.ts
import { version } from 'xlsx';
import { Component, OnInit } from '@angular/core'

import { Item } from './item'
import { ItemService } from './item.service'

@Component({
selector: 'ns-items',
templateUrl: './items.component.html',
})
export class ItemsComponent implements OnInit {
items: Array<Item>
version = `SheetJS - ${version}`;

constructor(private itemService: ItemService) {}

ngOnInit(): void {
this.items = this.itemService.getItems()
}
}

src/app/item/items.component.html references the version in the title:

src/app/item/items.component.html
<ActionBar [title]="version"></ActionBar>

<GridLayout>
<ListView [items]="items">
<ng-template let-item="item">
<StackLayout [nsRouterLink]="['/item', item.id]">
<Label [text]="item.name"></Label>
</StackLayout>
</ng-template>
</ListView>
</GridLayout>

Relaunch the app with ns run ios and the title bar should show the version.

NativeScript Step 4

5) Add the Import and Export buttons to the template:

src/app/item/items.component.html
<ActionBar [title]="version"></ActionBar>

<StackLayout>
<StackLayout orientation="horizontal">
<Button text="Import File" (tap)="import()" style="padding: 10px"></Button>
<Button text="Export File" (tap)="export()" style="padding: 10px"></Button>
</StackLayout>
<ListView [items]="items">
<ng-template let-item="item">
<StackLayout [nsRouterLink]="['/item', item.id]">
<Label [text]="item.name"></Label>
</StackLayout>
</ng-template>
</ListView>
</StackLayout>
src/app/item/items.component.ts
import { version, utils, read, write } from 'xlsx';
import { Dialogs } from '@nativescript/core';
import { encoding } from '@nativescript/core/text';
import { File, Folder, knownFolders, path } from '@nativescript/core/file-system';
import { Component, OnInit } from '@angular/core'

import { Item } from './item'
import { ItemService } from './item.service'

function get_handle_for_filename(filename: string): [File, string] {
const target: Folder = knownFolders.documents() || knownFolders.ios.sharedPublic();
const url: string = path.normalize(target.path + "///" + filename);
return [File.fromPath(url), url];
}

@Component({
selector: 'ns-items',
templateUrl: './items.component.html',
})
export class ItemsComponent implements OnInit {
items: Array<Item>
version: string = `SheetJS - ${version}`;

constructor(private itemService: ItemService) {}

ngOnInit(): void {
this.items = this.itemService.getItems()
}

/* Import button */
async import() {
}

/* Export button */
async export() {
}
}

Restart the app process and two buttons should show up at the top:

NativeScript Step 5

6) Implement import and export:

src/app/item/items.component.ts
import { version, utils, read, write } from 'xlsx';
import { Dialogs } from '@nativescript/core';
import { encoding } from '@nativescript/core/text';
import { File, Folder, knownFolders, path } from '@nativescript/core/file-system';
import { Component, OnInit } from '@angular/core'

import { Item } from './item'
import { ItemService } from './item.service'

function get_handle_for_filename(filename: string): [File, string] {
const target: Folder = knownFolders.documents() || knownFolders.ios.sharedPublic();
const url: string = path.normalize(target.path + "///" + filename);
return [File.fromPath(url), url];
}

@Component({
selector: 'ns-items',
templateUrl: './items.component.html',
})
export class ItemsComponent implements OnInit {
items: Array<Item>
version: string = `SheetJS - ${version}`;

constructor(private itemService: ItemService) {}

ngOnInit(): void {
this.items = this.itemService.getItems()
}

/* Import button */
async import() {
/* find appropriate path */
const [file, url] = get_handle_for_filename("SheetJSNS.csv");

try {
/* get binary string */
const bstr: string = await file.readText(encoding.ISO_8859_1);

/* read workbook */
const wb = read(bstr, { type: "binary" });

/* grab first sheet */
const wsname: string = wb.SheetNames[0];
const ws = wb.Sheets[wsname];

/* update table */
this.items = utils.sheet_to_json<Item>(ws);
Dialogs.alert(`Attempting to read to ${filename} in ${url}`);
} catch(e) { Dialogs.alert(e.message); }
}

/* Export button */
async export() {
/* find appropriate path */
const [file, url] = get_handle_for_filename("SheetJSNS.csv");

try {
/* create worksheet from data */
const ws = utils.json_to_sheet(this.items);

/* create workbook from worksheet */
const wb = utils.book_new();
utils.book_append_sheet(wb, ws, "Sheet1");

/* generate binary string */
const wbout: string = write(wb, { bookType: 'csv', type: 'binary' });

/* attempt to save binary string to file */
await file.writeText(wbout, encoding.ISO_8859_1);
Dialogs.alert(`Wrote to ${filename} in ${url}`);
} catch(e) { Dialogs.alert(e.message); }
}
}

Restart the app process.

Testing

The app can be tested with the following sequence in the simulator:

  • Hit "Export File". A dialog will print where the file was written

  • Open that file with a text editor. It will be a 3-column CSV:

id,name,role
1,Ter Stegen,Goalkeeper
3,Piqué,Defender
4,I. Rakitic,Midfielder
...

After the header row, add the line 0,SheetJS,Library:

id,name,role
0,SheetJS,Library
1,Ter Stegen,Goalkeeper
3,Piqué,Defender
...
  • Hit "Import File". A dialog will print the path of the file that was read. The first item in the list will change:

NativeScript Step 7

Quasar

note

This demo was tested on an Intel Mac on 2022 August 14. Quasar version 2.7.7. The iOS simulator runs iOS 15.5 on an iPhone SE 3rd generation.

This demo will use the Quasar ViteJS starter project with VueJS and Cordova.

Integration Details

The complete solution uses cordova-plugin-file for file operations. It can be installed like any other Cordova plugin:

cd src-cordova
cordova plugin add cordova-plugin-file
cd ..

Reading data

The q-file component presents an API reminiscent of File Input elements:

<q-file label="Load File" filled label-color="orange" @input="updateFile"/>

When binding to the input element, the callback receives an Event object:

import { read } from 'xlsx';

// assuming `todos` is a standard VueJS `ref`
async function updateFile(v) { try {
// `v.target.files[0]` is the desired file object
const files = (v.target as HTMLInputElement).files;
if(!files || files.length == 0) return;

// read first file
const wb = read(await files[0].arrayBuffer());

// get data of first worksheet as an array of objects
const data = utils.sheet_to_json(wb.Sheets[wb.SheetNames[0]]);

// update state
todos.value = data.map(row => ({id: row.Index, content: row.Name}));

} catch(e) { console.log(e); } }

Writing data

The API is shaped like the File and Directory Entries API. For clarity, since the code is a "pyramid of doom", the error handlers are omitted:

import { write } from 'xlsx';

// on iOS and android, `XLSX.write` with type "buffer" returns a `Uint8Array`
const u8: Uint8Array = write(wb, {bookType: "xlsx", type: "buffer"});
// Request filesystem access for persistent storage
window.requestFileSystem(window.PERSISTENT, 0, function(fs) {
// Request a handle to "SheetJSQuasar.xlsx", making a new file if necessary
fs.root.getFile("SheetJSQuasar.xlsx", {create: true}, entry => {
// Request a FileWriter for writing data
entry.createWriter(writer => {
// The FileWriter API needs an actual Blob
const data = new Blob([u8], {type: "application/vnd.ms-excel"});
// This callback is called if the write is successful
writer.onwriteend = () => {
// TODO: show a dialog
};
// writer.onerror will be invoked if there is an error in writing

// write the data
writer.write(data);
});
});
});

Demo

The demo draws from the ViteJS example. Familiarity with VueJS and TypeScript is assumed.

Complete Example (click to show)

0) Ensure all of the dependencies are installed. Install the CLI globally:

npm i -g @quasar/cli cordova

(you may need to run sudo npm i -g if there are permission issues)

1) Create a new app:

npm init quasar

When prompted:

  • "What would you like to build?": App with Quasar CLI
  • "Project folder": SheetJSQuasar
  • "Pick Quasar version": Quasar v2 (Vue 3 | latest and greatest)
  • "Pick script type": Typescript
  • "Pick Quasar App CLI variant": Quasar App CLI with Vite
  • "Package name": (just press enter, it will use the default sheetjsquasar
  • "Project product name": SheetJSQuasar
  • "Project description": SheetJS + Quasar
  • "Author": (just press enter, it will use your git config settings)
  • "Pick a Vue component style": Composition API
  • "Pick your CSS preprocessor": None
  • "Check the features needed for your project": Deselect everything
  • "Install project dependencies": No

2) Install dependencies:

cd SheetJSQuasar
npm i
npm i --save https://cdn.sheetjs.com/xlsx-latest/xlsx-latest.tgz

3) Set up Cordova:

quasar mode add cordova

When prompted, enter the app id org.sheetjs.quasar.

It will create a new src-cordova folder. Continue in that folder:

cd src-cordova
cordova platform add ios
cordova plugin add cordova-plugin-wkwebview-engine
cordova plugin add cordova-plugin-file
note

If there is an error Could not load API for iOS project, it needs to be reset:

cordova platform rm ios
cordova platform add ios
cordova plugin add cordova-plugin-file

Return to the project directory:

cd ..

4) Start the development server:

quasar dev -m ios
caution

If the app is blank or not refreshing, delete the app and close the simulator, then restart the development process.

Quasar Step 4

5) Add the Dialog plugin to quasar.config.js:

quasar.config.js
      // Quasar plugins
plugins: ['Dialog']

6) In the template section of src/pages/IndexPage.vue, add a Save button and a Load file picker component at the bottom of the page:

src/pages/IndexPage.vue
    <q-btn-group>
<q-file label="Load File" filled label-color="orange" @input="updateFile"/>
<q-btn label="Save File" @click="saveFile" />
</q-btn-group>
</q-page>
</template>

This uses two functions that should be added to the component script:

src/pages/IndexPage.vue
    const meta = ref<Meta>({
totalCount: 1200
});
function saveFile() {
}
async function updateFile(v) {
}
return { todos, meta, saveFile, updateFile };
}
});

The app should now show two buttons at the bottom:

Quasar Step 6

caution

If the app is blank or not refreshing, delete the app and close the simulator, then restart the development process.

7) Wire up the updateFile function:

src/pages/IndexPage.vue
import { defineComponent, ref } from 'vue';
import { read, write, utils } from 'xlsx';
import { useQuasar } from 'quasar';

export default defineComponent({
// ...
const $q = useQuasar();
function dialogerr(e) { $q.dialog({title: "Error!", message: e.message || String(e)}); }
function saveFile() {
}
async function updateFile(v) {
try {
const files = (v.target as HTMLInputElement).files;
if(!files || files.length == 0) return;

const wb = read(await files[0].arrayBuffer());

const data = utils.sheet_to_json(wb.Sheets[wb.SheetNames[0]]);
todos.value = data.map(row => ({id: row.Index, content: row.Name}));
} catch(e) { dialogerr(e); }
}

To test that reading works:

  • Download https://sheetjs.com/pres.numbers
  • In the simulator, click the Home icon to return to the home screen
  • Click on the "Files" icon
  • Click and drag pres.numbers from a Finder window into the simulator.

Quasar Step 7 save file

  • Make sure "On My iPhone" is highlighted and select "Save"
  • Click the Home icon again then select the SheetJSQuasar app
  • Click the "Load" button, then select "Choose File" and select pres:

Quasar Step 7 load file

Once selected, the screen should refresh with new contents:

Quasar Step 7 new data

8) Wire up the saveFile function:

    function saveFile() {
/* generate workbook from state */
const ws = utils.json_to_sheet(todos.value);
const wb = utils.book_new();
utils.book_append_sheet(wb, ws, "SheetJSQuasar");
const u8: Uint8Array = write(wb, {bookType: "xlsx", type: "buffer"});

/* save to file */
window.requestFileSystem(window.PERSISTENT, 0, function(fs) {
try {
fs.root.getFile("SheetJSQuasar.xlsx", {create: true}, entry => {
const msg = `File stored at ${$q.cordova.file.documentsDirectory} ${entry.fullPath}`;
entry.createWriter(writer => {
try {
const data = new Blob([u8], {type: "application/vnd.ms-excel"});
writer.onwriteend = () => {
try {
$q.dialog({title: "Success!", message: msg});
} catch(e) { dialogerr(e); }
};
writer.onerror = dialogerr;
writer.write(data);
} catch(e) { dialogerr(e); }
}, dialogerr);
}, dialogerr);
} catch(e) { dialogerr(e) }
}, dialogerr);
}

The page should revert to the old contents.

To test that writing works:

  • Click "Save File". You will see a popup with a location:

Quasar Step 8

  • Find the file and verify the contents are correct. Run in a new terminal:
find ~/Library/Developer/CoreSimulator -name SheetJSQuasar.xlsx |
while read x; do echo "$x"; npx xlsx-cli "$x"; done

Since the contents reverted, you should see

SheetJSQuasar
id,content
1,ct1
2,ct2
3,ct3
4,ct4
5,ct5
  • Use "Load File" to select pres.numbers again. Wait for the app to refresh.

  • Click "Save File", then re-run the command:

find ~/Library/Developer/CoreSimulator -name SheetJSQuasar.xlsx |
while read x; do echo "$x"; npx xlsx-cli "$x"; done

The contents from pres.numbers should show up now, with a new header row:

SheetJSQuasar
id,content
42,Bill Clinton
43,GeorgeW Bush
44,Barack Obama
45,Donald Trump
46,Joseph Biden

Ionic

note

This demo was tested on an Intel Mac on 2022 August 18 with Cordova. The file integration uses @ionic-native/file version 5.36.0.

The iOS simulator runs iOS 15.5 on an iPod Touch 7th Gen.

Telemetry

Before starting this demo, manually disable telemetry. On Linux and MacOS:

rm -rf ~/.ionic/
mkdir ~/.ionic
cat <<EOF > ~/.ionic/config.json
{
"version": "6.20.1",
"telemetry": false,
"npmClient": "npm"
}
EOF
npx @capacitor/cli telemetry off

To verify telemetry was disabled:

npx @ionic/cli config get -g telemetry
npx @capacitor/cli telemetry

Cordova

caution

The latest version of Ionic uses CapacitorJS. These notes are for Cordova apps.

Array<Array<any>> neatly maps to a table with ngFor:

<ion-grid>
<ion-row *ngFor="let row of data">
<ion-col *ngFor="let val of row">
{{val}}
</ion-col>
</ion-row>
</ion-grid>

@ionic-native/file reads and writes files on devices. readAsArrayBuffer returns ArrayBuffer objects suitable for array type, and array type can be converted to blobs that can be exported with writeFile:

/* read a workbook */
const ab: ArrayBuffer = await this.file.readAsArrayBuffer(url, filename);
const wb: XLSX.WorkBook = XLSX.read(bstr, {type: 'array'});

/* write a workbook */
const wbout: ArrayBuffer = XLSX.write(wb, { bookType: 'xlsx', type: 'array' });
let blob = new Blob([wbout], {type: 'application/octet-stream'});
this.file.writeFile(url, filename, blob, {replace: true});

Demo

The demo uses Cordova.

Complete Example (click to show)

0) Disable telemetry as noted in the warning.

Install required global dependencies:

npm i -g cordova-res @angular/cli native-run

Follow the React Native demo to ensure iOS and Android sims are ready.

1) Create a new project:

npx @ionic/cli start SheetJSIonic blank --type angular --cordova --quiet --no-git --no-link --confirm

If a prompt discusses Cordova and Capacitor, enter Yes to continue.

If a prompt asks about creating an Ionic account, enter N to opt out.

2) Set up Cordova:

npx @ionic/cli cordova platform add ios --confirm
npx @ionic/cli cordova plugin add cordova-plugin-file
npm install --save @ionic-native/core @ionic-native/file @ionic/cordova-builders

3) Install dependencies:

npm install --save https://cdn.sheetjs.com/xlsx-latest/xlsx-latest.tgz

4) Add @ionic-native/file to the module. Differences highlighted below:

src/app/app.module.ts
import { AppComponent } from './app.component';
import { AppRoutingModule } from './app-routing.module';

import { File } from '@ionic-native/file/ngx';

@NgModule({
declarations: [AppComponent],
imports: [BrowserModule, IonicModule.forRoot(), AppRoutingModule],

providers: [File, { provide: RouteReuseStrategy, useClass: IonicRouteStrategy }],
bootstrap: [AppComponent],
})
export class AppModule {}

5) Download home.page.ts and replace:

curl -o src/app/home/home.page.ts -L https://docs.sheetjs.com/ionic/home.page.ts

6) Test the app:

npx @ionic/cli cordova emulate ios

CapacitorJS

note

This demo was tested on an Intel Mac on 2022 August 26 with Svelte.

The iOS simulator runs iOS 15.5 on an iPhone 13 Pro Max.

Telemetry

Before starting this demo, manually disable telemetry. On Linux and MacOS:

npx @capacitor/cli telemetry off

To verify telemetry was disabled:

npx @capacitor/cli telemetry

Integration Details

This example uses Svelte, but the same principles apply to other frameworks.

Reading data

The standard HTML5 File Input element logic works in CapacitorJS:

<script>
import { read, utils } from 'xlsx';

let html = "";

/* show file picker, read file, load table */
async function importFile(evt) {
const f = evt.target.files[0];
const wb = read(await f.arrayBuffer());
const ws = wb.Sheets[wb.SheetNames[0]]; // get the first worksheet
html = utils.sheet_to_html(ws); // generate HTML and update state
}
</script>

<main>
<input type="file" on:change={importFile}/>
<div bind:this={tbl}>{@html html}</div>
</main>

Writing data

@capacitor/filesystem can write Base64 strings:

<script>
import { Filesystem, Directory } from '@capacitor/filesystem';
import { utils, writeXLSX } from 'xlsx';

let html = "";
let tbl;

/* get state data and export to XLSX */
async function exportFile() {
const elt = tbl.getElementsByTagName("TABLE")[0];
const wb = utils.table_to_book(elt);
/* generate Base64 string for Capacitor */
const data = writeXLSX(wb, { type: "base64" });
await Filesystem.writeFile({
data,
path: "SheetJSCap.xlsx",
directory: Directory.Documents
}); // write file
}

</script>

<main>
<button on:click={exportFile}>Export XLSX</button>
<div bind:this={tbl}>{@html html}</div>
</main>

Demo

Complete Example (click to show)

0) Disable telemetry as noted in the warning.

Follow the React Native demo to ensure iOS and Android sims are ready.

1) Create a new Svelte project:

npm create [email protected] sheetjs-cap -- --template svelte
cd sheetjs-cap

2) Install dependencies:

npm i --save https://cdn.sheetjs.com/xlsx-latest/xlsx-latest.tgz
npm i --save @capacitor/core @capacitor/cli @capacitor/ios @capacitor/filesystem

3) Create CapacitorJS structure:

npx cap init sheetjs-cap com.sheetjs.cap --web-dir=dist
npx cap add ios

4) Replace the contents of src/App.svelte with the following:

src/App.svelte
<script>
import { Filesystem, Directory, Encoding } from '@capacitor/filesystem';
import { onMount } from 'svelte';
import { read, utils, version, writeXLSX } from 'xlsx';

let html = "";
let tbl;

/* Fetch and update the state once */
onMount(async() => {
const f = await (await fetch("https://sheetjs.com/pres.xlsx")).arrayBuffer();
const wb = read(f); // parse the array buffer
const ws = wb.Sheets[wb.SheetNames[0]]; // get the first worksheet
html = utils.sheet_to_html(ws); // generate HTML and update state
});

/* get state data and export to XLSX */
async function exportFile() {
const elt = tbl.getElementsByTagName("TABLE")[0];
const wb = utils.table_to_book(elt);
/* generate Base64 string for Capacitor */
const data = writeXLSX(wb, { type: "base64" });
/* write */
await Filesystem.writeFile({
path: "SheetJSCap.xlsx",
data,
directory: Directory.Documents
});
}

/* show file picker, read file, load table */
async function importFile(evt) {
const f = evt.target.files[0];
const wb = read(await f.arrayBuffer());
const ws = wb.Sheets[wb.SheetNames[0]]; // get the first worksheet
html = utils.sheet_to_html(ws); // generate HTML and update state
}
</script>

<main>
<h3>SheetJS × CapacitorJS { version }</h3>
<input type="file" on:change={importFile}/>
<button on:click={exportFile}>Export XLSX</button>
<div bind:this={tbl}>{@html html}</div>
</main>

5) Test the app:

npm run build; npx cap sync; npx cap run ios

There are 3 steps: build the Svelte app, sync with CapacitorJS, and run sim. This sequence must be run every time to ensure changes are propagated.