docs.sheetjs.com/02-nativescript.md at e1402a842418a256e21f54a883fd5088169a0d31

Tinywan/docs.sheetjs.com

Fork 0

forked from sheetjs/docs.sheetjs.com

SheetJS 7f366322e7 cell

2023-09-22 02:44:32 -04:00

11 KiB

Raw Blame History

title

pagination_prev

pagination_next

sidebar_position

sidebar_custom_props

NativeScript

demos/static/index

demos/desktop/index

summary
JS + Native Elements

import current from '/version.js'; import CodeBlock from '@theme/CodeBlock';

The SheetJS NodeJS Module can be imported from any component or script in the app.

The "Complete Example" creates an app that looks like the screenshots below:

iOS	Android

Integration Details

The discussion covers the NativeScript + Angular integration. Familiarity with Angular and TypeScript is assumed.

The @nativescript/core/file-system package provides classes for file access. The File class does not support binary data, but the file access singleton from @nativescript/core does support reading and writing ArrayBuffer.

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

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

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

Reading Local Files

getFileAccess().readBufferAsync can read data:

import { getFileAccess } from '@nativescript/core';
import { read } from 'xlsx';

/* find appropriate path */
const url = get_url_for_filename("SheetJSNS.xls");

/* get data */
const ab: ArrayBuffer = await getFileAccess().readBufferAsync(url);

/* read workbook */
const wb = read(ab);

Writing Local Files

getFileAccess().writeBufferAsync can write data. iOS supports Uint8Array directly but Android requires a true array of numbers:

import { getFileAccess } from '@nativescript/core';
import { write } from 'xlsx';

/* find appropriate path */
const url = get_url_for_filename("SheetJSNS.xls");

/* generate Uint8Array */
const u8: Uint8Array = write(wb, { bookType: 'xls', type: 'binary' });

/* attempt to save Uint8Array to file */
await getFileAccess().writeBufferAsync(url, global.isAndroid ? (Array.from(u8) as any) : u8);

Fetching Remote Files

getFile from @nativescript/core/http can download files. After storing the file in a temporary folder, getFileAccess().readBufferAsync can read the data:

import { knownFolders, path, getFileAccess } from '@nativescript/core'
import { getFile } from '@nativescript/core/http';
import { read } from 'xlsx';

/* generate temporary path for the new file */
const temp: string = path.join(knownFolders.temp().path, "pres.xlsx");

/* download file */
const file = await getFile("https://sheetjs.com/pres.xlsx", temp)

/* get data */
const ab: ArrayBuffer = await getFileAccess().readBufferAsync(file.path);

/* read workbook */
const wb = read(ab);

Demo

:::note

This demo was tested on an Intel Mac on 2023 May 21. NativeScript version (as verified with ns --version) is 8.5.3.

The iOS simulator runs iOS 16.2 on an iPhone 14 Pro Max.

The Android simulator runs Android 12.0 (S) API 31 on a Pixel 3.

:::

Follow the official Environment Setup instructions

Base Project

Create a skeleton NativeScript + Angular app:

ns create SheetJSNS --ng

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

From the project folder, install the library:

{\ npm i --save https://cdn.sheetjs.com/xlsx-${current}/xlsx-${current}.tgz}

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

src/app/item/items.component.ts should import the version string:

// highlight-next-line
import { version } from 'xlsx';
import { Component, OnInit } from '@angular/core'

// ...

export class ItemsComponent implements OnInit {
  items: Array<Item>
  // highlight-next-line
  version = `SheetJS - ${version}`;

  constructor(private itemService: ItemService) {}
// ...

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

<!-- highlight-next-line -->
<ActionBar [title]="version"></ActionBar>

<GridLayout>
<!-- ... -->

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

Local Files

Add the Import and Export buttons to the template:

<ActionBar [title]="version"></ActionBar>

<!-- highlight-start -->
<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>
<!-- highlight-end -->
  <ListView [items]="items">
    <!-- ... -->
  </ListView>
<!-- highlight-next-line -->
</StackLayout>

// highlight-start
import { version, utils, read, write } from 'xlsx';
import { Dialogs, getFileAccess } from '@nativescript/core';
import { Folder, knownFolders, path } from '@nativescript/core/file-system';
// highlight-end
import { Component, OnInit } from '@angular/core'

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

// highlight-start
function get_url_for_filename(filename: string): string {
  const target: Folder = knownFolders.documents() || knownFolders.ios.sharedPublic();
  return path.normalize(target.path + "///" + filename);
}
// highlight-end

@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()
  }

  // highlight-start
  /* Import button */
  async import() {
  }

  /* Export button */
  async export() {
  }
  // highlight-end
}

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

Implement import and export by adding the highlighted lines:

  /* Import button */
  async import() {
    // highlight-start
    /* find appropriate path */
    const url = get_url_for_filename("SheetJSNS.xls");

    try {
      await Dialogs.alert(`Attempting to read from SheetJSNS.xls at ${url}`);
      /* get data */
      const ab: ArrayBuffer = await getFileAccess().readBufferAsync(url);

      /* read workbook */
      const wb = read(ab);

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

      /* update table */
      this.items = utils.sheet_to_json<Item>(ws);
    } catch(e) { await Dialogs.alert(e.message); }
    // highlight-end
  }

  /* Export button */
  async export() {
    // highlight-start
    /* find appropriate path */
    const url = get_url_for_filename("SheetJSNS.xls");

    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 Uint8Array */
      const u8: Uint8Array = write(wb, { bookType: 'xls', type: 'buffer' });

      /* attempt to save Uint8Array to file */
      await getFileAccess().writeBufferAsync(url, global.isAndroid ? (Array.from(u8) as any) : u8);
      await Dialogs.alert(`Wrote to SheetJSNS.xls at ${url}`);
    } catch(e) { await Dialogs.alert(e.message); }
    // highlight-end
  }

iOS

Relaunch the app with ns run ios

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

Tap "Export File". A dialog will print where the file was written
Open the file with a spreadsheet editor.

After the header row, insert a row with cell A2 = 0, B2 = SheetJS, C2 = Library:

id | name       | role
 0 | SheetJS    | Library
 1 | Ter Stegen | Goalkeeper
 3 | Piqué      | Defender
...

Restart the app after saving the file.

Tap "Import File". A dialog will print the path of the file that was read. The first item in the list will change:

Android

Launch the app with ns run android. If the app does not automatically launch, manually open the SheetJSNS app.