docs.sheetjs.com/22-vue.md at 734f70e6d9ff97240833ea47ea9ad7f05fe467c5

LankyMoose/docs.sheetjs.com

2022-08-22 23:20:02 -04:00

5.7 KiB

Raw Blame History

sidebar_position	title
22	VueJS

VueJS is a JS library for building user interfaces.

This demo tries to cover common Vue data flow ideas and strategies. Single-File Components (SFC) and VueJS familiarity is assumed.

Other demos cover general VueJS deployments, including:

Installation

The "Frameworks" section covers installation with Yarn and other package managers.

The library can be imported directly from JS or JSX code with:

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

Internal State

The various SheetJS APIs work with various data shapes. The preferred state depends on the application.

Array of Objects

Typically, some users will create a spreadsheet with source data that should be loaded into the site. This sheet will have known columns. For example, our presidents sheet has "Name" / "Index" columns:

This naturally maps to an array of typed objects, as in the TS example below:

import { read, utils } from 'xlsx';

interface President {
  Name: string;
  Index: number;
}

const f = await (await fetch("https://sheetjs.com/pres.xlsx")).arrayBuffer();
const wb = read(f);
const data = utils.sheet_to_json<President>(wb.Sheets[wb.SheetNames[0]]);
console.log(data);

data will be an array of objects:

[
  { Name: "Bill Clinton", Index: 42 },
  { Name: "GeorgeW Bush", Index: 43 },
  { Name: "Barack Obama", Index: 44 },
  { Name: "Donald Trump", Index: 45 },
  { Name: "Joseph Biden", Index: 46 }
]

A component will typically map over the data. The following example generates a TABLE with a row for each President:

<script setup>
import { ref, onMounted } from "vue";
import { read, utils, writeFileXLSX } from 'xlsx';

const rows = ref([]);

onMounted(async() => {
  /* Download from https://sheetjs.com/pres.numbers */
  const f = await fetch("https://sheetjs.com/pres.numbers");
  const ab = await f.arrayBuffer();

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

  /* update data */
  rows.value = utils.sheet_to_json(wb.Sheets[wb.SheetNames[0]]);
});

/* get state data and export to XLSX */
function exportFile() {
  const ws = utils.json_to_sheet(rows.value);
  const wb = utils.book_new();
  utils.book_append_sheet(wb, ws, "Data");
  writeFileXLSX(wb, "SheetJSVueAoO.xlsx");
}
</script>

<template>
  <table><thead><th>Name</th><th>Index</th></thead><tbody>
    <tr v-for="(row, idx) in rows" :key="idx">
      <td>{{ row.Name }}</td>
      <td>{{ row.Index }}</td>
    </tr>
  </tbody><tfoot><td colSpan={2}>
    <button @click="exportFile">Export XLSX</button>
  </td></tfoot></table>
</template>

HTML

The main disadvantage of the Array of Objects approach is the specific nature of the columns. For more general use, passing around an Array of Arrays works. However, this does not handle merge cells well!

The sheet_to_html function generates HTML that is aware of merges and other worksheet features. VueJS v-html attribute allows assignment of innerHTML attribute, effectively inserting the code into the page:

<script setup>
import { ref, onMounted } from "vue";
import { read, utils, writeFileXLSX } from 'xlsx';

const html = ref("");
const tableau = ref();

onMounted(async() => {
  /* Download from https://sheetjs.com/pres.numbers */
  const f = await fetch("https://sheetjs.com/pres.numbers");
  const ab = await f.arrayBuffer();

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

  /* update data */
  html.value = utils.sheet_to_html(wb.Sheets[wb.SheetNames[0]]);
});

/* get live table and export to XLSX */
function exportFile() {
  const wb = utils.table_to_book(tableau.value.getElementsByTagName("TABLE")[0])
  writeFileXLSX(wb, "SheetJSVueHTML.xlsx");
}
</script>

<template>
  <div v-html="html"></div>
  <button @click="exportFile">Export XLSX</button>
</template>

Rows and Columns

Some data grids and UI components split worksheet state in two parts: an array of column attribute objects and an array of row objects. The former is used to generate column headings and for indexing into the row objects.

The safest approach is to use an array of arrays for state and to generate column objects that map to A1-Style column headers.

The Vue Table Lite demo uses this approach with the following column and row structure:

/* rows are generated with a simple array of arrays */
rows.value = utils.sheet_to_json(worksheet, { header: 1 });

/* column objects are generated based on the worksheet range */
const range = utils.decode_range(ws["!ref"]||"A1");
columns.value = Array.from({ length: range.e.c + 1 }, (_, i) => ({
  /* for an array of arrays, the keys are "0", "1", "2", ... */
  field: String(i),
  /* column labels: encode_col translates 0 -> "A", 1 -> "B", 2 -> "C", ... */
  label: XLSX.utils.encode_col(i)
}));

Legacy Deployments

The Standalone Scripts play nice with legacy deployments that do not use a bundler.

The legacy demos show a simple VueJS component. It is written in ES5 syntax. The pages are not minified and "View Source" should be used to inspect.

There is a shared component SheetJS-vue.js

:::caution

The entire demo is designed to run in Internet Explorer and does not reflect modern design patterns.

:::

5.7 KiB Raw Blame History