forked from sheetjs/docs.sheetjs.com
375 lines
11 KiB
Plaintext
375 lines
11 KiB
Plaintext
---
|
|
sidebar_position: 3
|
|
---
|
|
|
|
# Complete Example
|
|
|
|
SheetJS presents a simple JS interface that works with "Array of Arrays" and
|
|
"Array of JS Objects". The API functions are building blocks that should be
|
|
combined with other JS APIs to solve problems.
|
|
|
|
The discussion focuses on the problem solving mindset. API details are covered
|
|
in other parts of the documentation.
|
|
|
|
The goal of this example is to generate a XLSB workbook of US President names
|
|
and birthdays. [Click here](#live-demo) to jump to the live demo
|
|
|
|
## Acquire Data
|
|
|
|
### Raw Data
|
|
|
|
[The raw data is available in JSON form](https://theunitedstates.io/congress-legislators/executive.json).
|
|
For convenience, it has been [mirrored here](https://sheetjs.com/executive.json)
|
|
|
|
The data result is an Array of objects. This is the data for John Adams:
|
|
|
|
```js
|
|
{
|
|
"id": { /* (data omitted) */ },
|
|
"name": {
|
|
"first": "John", // <-- first name
|
|
"last": "Adams" // <-- last name
|
|
},
|
|
"bio": {
|
|
"birthday": "1735-10-19", // <-- birthday
|
|
"gender": "M"
|
|
},
|
|
"terms": [
|
|
{ "type": "viceprez", /* (other fields omitted) */ },
|
|
{ "type": "viceprez", /* (other fields omitted) */ },
|
|
{ "type": "prez", /* (other fields omitted) */ }
|
|
]
|
|
}
|
|
```
|
|
|
|
### Filtering for Presidents
|
|
|
|
The dataset includes Aaron Burr, a Vice President who was never President!
|
|
|
|
`Array#filter` creates a new array with the desired rows. A President served
|
|
at least one term with `type` set to `"prez"`. To test if a particular row has
|
|
at least one `"prez"` term, `Array#some` is another native JS function. The
|
|
complete filter would be:
|
|
|
|
```js
|
|
const prez = raw_data.filter(row => row.terms.some(term => term.type === "prez"));
|
|
```
|
|
|
|
### Reshaping the Array
|
|
|
|
For this example, the name will be the first name combined with the last name
|
|
(`row.name.first + " " + row.name.last`) and the birthday will be the subfield
|
|
`row.bio.birthday`. Using `Array#map`, the dataset can be massaged in one call:
|
|
|
|
```js
|
|
const rows = prez.map(row => ({
|
|
name: row.name.first + " " + row.name.last,
|
|
birthday: row.bio.birthday
|
|
}));
|
|
```
|
|
|
|
The result is an array of "simple" objects with no nesting:
|
|
|
|
```js
|
|
[
|
|
{ name: "George Washington", birthday: "1732-02-22" },
|
|
{ name: "John Adams", birthday: "1735-10-19" },
|
|
// ... one row per President
|
|
]
|
|
```
|
|
|
|
## Create a Workbook
|
|
|
|
With the cleaned dataset, `XLSX.utils.json_to_sheet` generates a worksheet:
|
|
|
|
```js
|
|
const worksheet = XLSX.utils.json_to_sheet(rows);
|
|
```
|
|
|
|
`XLSX.utils.book_new` creates a new workbook and `XLSX.utils.book_append_sheet`
|
|
appends a worksheet to the workbook. The new worksheet will be called "Dates":
|
|
|
|
```js
|
|
const workbook = XLSX.utils.book_new();
|
|
XLSX.utils.book_append_sheet(workbook, worksheet, "Dates");
|
|
```
|
|
|
|
## Clean up Workbook
|
|
|
|
The data is in the workbook and can be exported.
|
|
|
|
|
|
|
|
There are multiple opportunities for improvement: the headers can be renamed and
|
|
the column widths can be adjusted. [SheetJS Pro](https://sheetjs.com/pro) offers
|
|
additional styling options like cell styling and frozen rows.
|
|
|
|
<details><summary><b>Changing Header Names</b> (click to show)</summary>
|
|
|
|
By default, `json_to_sheet` creates a worksheet with a header row. In this case,
|
|
the headers come from the JS object keys: "name" and "birthday".
|
|
|
|
The headers are in cells A1 and B1. `XLSX.utils.sheet_add_aoa` can write text
|
|
values to the existing worksheet starting at cell A1:
|
|
|
|
```js
|
|
XLSX.utils.sheet_add_aoa(worksheet, [["Name", "Birthday"]], { origin: "A1" });
|
|
```
|
|
|
|
</details>
|
|
|
|
<details><summary><b>Changing Column Widths</b> (click to show)</summary>
|
|
|
|
Some of the names are longer than the default column width. Column widths are
|
|
set by setting the `"!cols"` worksheet property.
|
|
|
|
The following line sets the width of column A to approximately 10 characters:
|
|
|
|
```js
|
|
worksheet["!cols"] = [ { wch: 10 } ]; // set column A width to 10 characters
|
|
```
|
|
|
|
One `Array#reduce` call over `rows` can calculate the maximum width:
|
|
|
|
```js
|
|
const max_width = rows.reduce((w, r) => Math.max(w, r.name.length), 10);
|
|
worksheet["!cols"] = [ { wch: max_width } ];
|
|
```
|
|
|
|
</details>
|
|
|
|
## Export a File
|
|
|
|
`XLSX.writeFile` creates a spreadsheet file and tries to write it to the system.
|
|
In the browser, it will try to prompt the user to download the file. In NodeJS,
|
|
it will write to the local directory.
|
|
|
|
```js
|
|
XLSX.writeFile(workbook, "Presidents.xlsb");
|
|
```
|
|
|
|
|
|
|
|
|
|
## Live Demo
|
|
|
|
```jsx live
|
|
function Presidents() { return ( <button onClick={async () => {
|
|
/* fetch JSON data and parse */
|
|
const url = "https://sheetjs.com/executive.json";
|
|
const raw_data = await (await fetch(url)).json();
|
|
|
|
/* filter for the Presidents */
|
|
const prez = raw_data.filter(row => row.terms.some(term => term.type === "prez"));
|
|
|
|
/* flatten objects */
|
|
const rows = prez.map(row => ({
|
|
name: row.name.first + " " + row.name.last,
|
|
birthday: row.bio.birthday
|
|
}));
|
|
|
|
/* generate worksheet and workbook */
|
|
const worksheet = XLSX.utils.json_to_sheet(rows);
|
|
const workbook = XLSX.utils.book_new();
|
|
XLSX.utils.book_append_sheet(workbook, worksheet, "Dates");
|
|
|
|
/* fix headers */
|
|
XLSX.utils.sheet_add_aoa(worksheet, [["Name", "Birthday"]], { origin: "A1" });
|
|
|
|
/* calculate column width */
|
|
const max_width = rows.reduce((w, r) => Math.max(w, r.name.length), 10);
|
|
worksheet["!cols"] = [ { wch: max_width } ];
|
|
|
|
/* create an XLSX file and try to save to Presidents.xlsb */
|
|
XLSX.writeFile(workbook, "Presidents.xlsb");
|
|
}}><b>Click to Generate file!</b></button> ); }
|
|
```
|
|
|
|
## Run the Demo Locally
|
|
|
|
import Tabs from '@theme/Tabs';
|
|
import TabItem from '@theme/TabItem';
|
|
|
|
<Tabs>
|
|
<TabItem value="browser" label="Browser">
|
|
|
|
Save the following script to `snippet.html` and open the page. The page must be
|
|
hosted (no `file:///` access).
|
|
|
|
<https://sheetjs.com/pres.html> is a hosted version of the page.
|
|
|
|
```html
|
|
<body>
|
|
<script src="https://cdn.sheetjs.com/xlsx-latest/package/dist/xlsx.full.min.js"></script>
|
|
<script>
|
|
(async() => {
|
|
/* fetch JSON data and parse */
|
|
const url = "https://sheetjs.com/executive.json";
|
|
const raw_data = await (await fetch(url)).json();
|
|
|
|
/* filter for the Presidents */
|
|
const prez = raw_data.filter(row => row.terms.some(term => term.type === "prez"));
|
|
|
|
/* flatten objects */
|
|
const rows = prez.map(row => ({
|
|
name: row.name.first + " " + row.name.last,
|
|
birthday: row.bio.birthday
|
|
}));
|
|
|
|
/* generate worksheet and workbook */
|
|
const worksheet = XLSX.utils.json_to_sheet(rows);
|
|
const workbook = XLSX.utils.book_new();
|
|
XLSX.utils.book_append_sheet(workbook, worksheet, "Dates");
|
|
|
|
/* fix headers */
|
|
XLSX.utils.sheet_add_aoa(worksheet, [["Name", "Birthday"]], { origin: "A1" });
|
|
|
|
/* calculate column width */
|
|
const max_width = rows.reduce((w, r) => Math.max(w, r.name.length), 10);
|
|
worksheet["!cols"] = [ { wch: max_width } ];
|
|
|
|
/* create an XLSX file and try to save to Presidents.xlsb */
|
|
XLSX.writeFile(workbook, "Presidents.xlsb");
|
|
})();
|
|
</script>
|
|
<body>
|
|
```
|
|
</TabItem>
|
|
<TabItem value="nodejs" label="NodeJS">
|
|
|
|
Install the dependencies:
|
|
|
|
```bash
|
|
$ npm i --save https://cdn.sheetjs.com/xlsx-latest/xlsx-latest.tgz
|
|
```
|
|
|
|
Save the following script to `snippet.js` and run `node snippet.js`:
|
|
|
|
```js
|
|
const XLSX = require("xlsx");
|
|
|
|
(async() => {
|
|
/* fetch JSON data and parse */
|
|
const url = "https://sheetjs.com/executive.json";
|
|
const raw_data = await (await fetch(url)).json();
|
|
|
|
/* filter for the Presidents */
|
|
const prez = raw_data.filter(row => row.terms.some(term => term.type === "prez"));
|
|
|
|
/* flatten objects */
|
|
const rows = prez.map(row => ({
|
|
name: row.name.first + " " + row.name.last,
|
|
birthday: row.bio.birthday
|
|
}));
|
|
|
|
/* generate worksheet and workbook */
|
|
const worksheet = XLSX.utils.json_to_sheet(rows);
|
|
const workbook = XLSX.utils.book_new();
|
|
XLSX.utils.book_append_sheet(workbook, worksheet, "Dates");
|
|
|
|
/* fix headers */
|
|
XLSX.utils.sheet_add_aoa(worksheet, [["Name", "Birthday"]], { origin: "A1" });
|
|
|
|
/* calculate column width */
|
|
const max_width = rows.reduce((w, r) => Math.max(w, r.name.length), 10);
|
|
worksheet["!cols"] = [ { wch: max_width } ];
|
|
|
|
/* create an XLSX file and try to save to Presidents.xlsb */
|
|
XLSX.writeFile(workbook, "Presidents.xlsb");
|
|
})();
|
|
```
|
|
|
|
Native `fetch` support was added in NodeJS 18. For older versions of NodeJS,
|
|
the script will throw an error `fetch is not defined`. A third-party library
|
|
like `axios` presents a similar API for fetching data:
|
|
|
|
<details><summary><b>Example using axios</b> (click to show)</summary>
|
|
|
|
Install the dependencies:
|
|
|
|
```bash
|
|
$ npm i --save https://cdn.sheetjs.com/xlsx-latest/xlsx-latest.tgz
|
|
```
|
|
|
|
The differences in the script are highlighted below.
|
|
|
|
```js
|
|
const XLSX = require("xlsx");
|
|
// highlight-next-line
|
|
const axios = require("axios");
|
|
|
|
(async() => {
|
|
/* fetch JSON data and parse */
|
|
const url = "https://sheetjs.com/executive.json";
|
|
// highlight-next-line
|
|
const raw_data = (await axios(url, {responseType: "json"})).data;
|
|
|
|
/* filter for the Presidents */
|
|
const prez = raw_data.filter(row => row.terms.some(term => term.type === "prez"));
|
|
|
|
/* flatten objects */
|
|
const rows = prez.map(row => ({
|
|
name: row.name.first + " " + row.name.last,
|
|
birthday: row.bio.birthday
|
|
}));
|
|
|
|
/* generate worksheet and workbook */
|
|
const worksheet = XLSX.utils.json_to_sheet(rows);
|
|
const workbook = XLSX.utils.book_new();
|
|
XLSX.utils.book_append_sheet(workbook, worksheet, "Dates");
|
|
|
|
/* fix headers */
|
|
XLSX.utils.sheet_add_aoa(worksheet, [["Name", "Birthday"]], { origin: "A1" });
|
|
|
|
/* calculate column width */
|
|
const max_width = rows.reduce((w, r) => Math.max(w, r.name.length), 10);
|
|
worksheet["!cols"] = [ { wch: max_width } ];
|
|
|
|
/* create an XLSX file and try to save to Presidents.xlsb */
|
|
XLSX.writeFile(workbook, "Presidents.xlsb");
|
|
})();
|
|
```
|
|
|
|
</details>
|
|
|
|
</TabItem>
|
|
<TabItem value="deno" label="Deno">
|
|
|
|
Save the following script to `snippet.ts` and run with
|
|
`deno run --allow-net --allow-write snippet.ts`:
|
|
|
|
```js
|
|
// @deno-types="https://cdn.sheetjs.com/xlsx-latest/package/types/index.d.ts"
|
|
import * as XLSX from 'https://cdn.sheetjs.com/xlsx-latest/package/xlsx.mjs';
|
|
|
|
/* fetch JSON data and parse */
|
|
const url = "https://sheetjs.com/executive.json";
|
|
const raw_data = await (await fetch(url)).json();
|
|
|
|
/* filter for the Presidents */
|
|
const prez = raw_data.filter((row: any) => row.terms.some((term: any) => term.type === "prez"));
|
|
|
|
/* flatten objects */
|
|
const rows = prez.map((row: any) => ({
|
|
name: row.name.first + " " + row.name.last,
|
|
birthday: row.bio.birthday
|
|
}));
|
|
|
|
/* generate worksheet and workbook */
|
|
const worksheet = XLSX.utils.json_to_sheet(rows);
|
|
const workbook = XLSX.utils.book_new();
|
|
XLSX.utils.book_append_sheet(workbook, worksheet, "Dates");
|
|
|
|
/* fix headers */
|
|
XLSX.utils.sheet_add_aoa(worksheet, [["Name", "Birthday"]], { origin: "A1" });
|
|
|
|
/* calculate column width */
|
|
const max_width = rows.reduce((w: number, r: any) => Math.max(w, r.name.length), 10);
|
|
worksheet["!cols"] = [ { wch: max_width } ];
|
|
|
|
/* create an XLSX file and try to save to Presidents.xlsb */
|
|
XLSX.writeFile(workbook, "Presidents.xlsb");
|
|
```
|
|
|
|
</TabItem>
|
|
</Tabs> |