556 lines
15 KiB
Plaintext
556 lines
15 KiB
Plaintext
---
|
|
title: HTTP Downloads
|
|
pagination_next: demos/net/upload/index
|
|
---
|
|
|
|
<head>
|
|
<script src="https://unpkg.com/axios/dist/axios.min.js"></script>
|
|
<script src="https://unpkg.com/superagent@7.1.1/dist/superagent.min.js"></script>
|
|
</head>
|
|
|
|
import current from '/version.js';
|
|
import CodeBlock from '@theme/CodeBlock';
|
|
|
|
:::info pass
|
|
|
|
This demo focuses on downloading files. Other demos cover other HTTP use cases:
|
|
|
|
- ["HTTP Uploads"](/docs/demos/net/upload) covers uploading files
|
|
- ["HTTP Server Processing"](/docs/demos/net/server) covers HTTP servers
|
|
|
|
:::
|
|
|
|
`XMLHttpRequest` and `fetch` browser APIs enable binary data transfer between
|
|
web browser clients and web servers. Since this library works in web browsers,
|
|
server conversion work can be offloaded to the client! This demo shows a few
|
|
common scenarios involving browser APIs and popular wrapper libraries.
|
|
|
|
:::caution Third-Party Hosts and Binary Data
|
|
|
|
Third-party cloud platforms such as AWS may corrupt raw binary downloads by
|
|
encoding requests and responses in UTF-8 strings.
|
|
|
|
For AWS, in the "Binary Media Types" section of the API Gateway console, the
|
|
`"application/vnd.ms-excel"` type should be added to ensure that AWS Lambda
|
|
functions functions can send files to clients.
|
|
|
|
:::
|
|
|
|
## Downloading Binary Data
|
|
|
|
Most interesting spreadsheet files are binary data that contain byte sequences
|
|
that represent invalid UTF-8 characters.
|
|
|
|
The APIs generally have a way to control the interpretation of the downloaded
|
|
data. The `arraybuffer` response type usually forces the data to be presented
|
|
as an `ArrayBuffer` which can be parsed directly with the SheetJS `read` method[^1].
|
|
|
|
For example, with `fetch`:
|
|
|
|
```js
|
|
/* download data into an ArrayBuffer object */
|
|
const res = await fetch("https://sheetjs.com/pres.numbers");
|
|
const ab = await res.arrayBuffer(); // recover data as ArrayBuffer
|
|
|
|
/* parse file */
|
|
const wb = XLSX.read(ab);
|
|
```
|
|
|
|
## Browser Demos
|
|
|
|
The included demos focus on an editable table.
|
|
|
|
When the page is accessed, the browser will attempt to download <https://sheetjs.com/pres.numbers>
|
|
and read the workbook. The old table will be replaced with a table whose
|
|
contents match the first worksheet. The table is generated using the SheetJS
|
|
`sheet_to_html` method[^2]
|
|
|
|
|
|
### XMLHttpRequest
|
|
|
|
For downloading data, the `arraybuffer` response type generates an `ArrayBuffer`
|
|
that can be viewed as an `Uint8Array` and fed to `XLSX.read` using `array` type:
|
|
|
|
```js
|
|
/* set up an async GET request */
|
|
var req = new XMLHttpRequest();
|
|
req.open("GET", url, true);
|
|
req.responseType = "arraybuffer";
|
|
|
|
req.onload = function(e) {
|
|
/* parse the data when it is received */
|
|
var data = new Uint8Array(req.response);
|
|
var workbook = XLSX.read(data, {type:"array"});
|
|
/* DO SOMETHING WITH workbook HERE */
|
|
};
|
|
req.send();
|
|
```
|
|
|
|
<details><summary><b>Live Download demo</b> (click to show)</summary>
|
|
|
|
This demo uses `XMLHttpRequest` to download <https://sheetjs.com/pres.numbers>
|
|
and show the data in an HTML table.
|
|
|
|
```jsx live
|
|
function SheetJSXHRDL() {
|
|
const [__html, setHTML] = React.useState("");
|
|
|
|
/* Fetch and update HTML */
|
|
React.useEffect(async() => {
|
|
/* Fetch file */
|
|
const req = new XMLHttpRequest();
|
|
req.open("GET", "https://sheetjs.com/pres.numbers", true);
|
|
req.responseType = "arraybuffer";
|
|
req.onload = e => {
|
|
/* Parse file */
|
|
const wb = XLSX.read(new Uint8Array(req.response));
|
|
const ws = wb.Sheets[wb.SheetNames[0]];
|
|
|
|
/* Generate HTML */
|
|
setHTML(XLSX.utils.sheet_to_html(ws));
|
|
};
|
|
req.send();
|
|
}, []);
|
|
|
|
return ( <div dangerouslySetInnerHTML={{ __html }}/> );
|
|
}
|
|
```
|
|
|
|
</details>
|
|
|
|
|
|
### fetch
|
|
|
|
For downloading data, `Response#arrayBuffer` resolves to an `ArrayBuffer` that
|
|
can be converted to `Uint8Array` and passed to `XLSX.read`:
|
|
|
|
```js
|
|
fetch(url).then(function(res) {
|
|
/* get the data as a Blob */
|
|
if(!res.ok) throw new Error("fetch failed");
|
|
return res.arrayBuffer();
|
|
}).then(function(ab) {
|
|
/* parse the data when it is received */
|
|
var data = new Uint8Array(ab);
|
|
var workbook = XLSX.read(data, {type:"array"});
|
|
|
|
/* DO SOMETHING WITH workbook HERE */
|
|
});
|
|
```
|
|
|
|
<details><summary><b>Live Download demo</b> (click to show)</summary>
|
|
|
|
This demo uses `fetch` to download <https://sheetjs.com/pres.numbers> and show
|
|
the data in an HTML table.
|
|
|
|
```jsx live
|
|
function SheetJSFetchDL() {
|
|
const [__html, setHTML] = React.useState("");
|
|
|
|
/* Fetch and update HTML */
|
|
React.useEffect(async() => {
|
|
/* Fetch file */
|
|
const res = await fetch("https://sheetjs.com/pres.numbers");
|
|
const ab = await res.arrayBuffer();
|
|
|
|
/* Parse file */
|
|
const wb = XLSX.read(ab);
|
|
const ws = wb.Sheets[wb.SheetNames[0]];
|
|
|
|
/* Generate HTML */
|
|
setHTML(XLSX.utils.sheet_to_html(ws));
|
|
}, []);
|
|
|
|
return ( <div dangerouslySetInnerHTML={{ __html }}/> );
|
|
}
|
|
```
|
|
|
|
</details>
|
|
|
|
### jQuery
|
|
|
|
[jQuery](https://jquery.com/) is a JavaScript library that includes helpers for
|
|
performing "Ajax" network requests. `jQuery.ajax` (`$.ajax`) does not support
|
|
binary data out of the box[^3]. A custom `ajaxTransport` can add support.
|
|
|
|
SheetJS users have reported success with `jquery.binarytransport.js`[^4] in IE10.
|
|
|
|
After including the main `jquery.js` and `jquery.binarytransport.js` scripts,
|
|
`$.ajax` will support `dataType: "binary"` and `processData: false`.
|
|
|
|
**[Live Download Demo](pathname:///jquery/index.html)**
|
|
|
|
In a GET request, the default behavior is to return a `Blob` object. Passing
|
|
`responseType: "arraybuffer"` returns a proper `ArrayBuffer` object in IE10:
|
|
|
|
```js
|
|
$.ajax({
|
|
type: "GET", url: "https://sheetjs.com/pres.numbers",
|
|
|
|
/* suppress jQuery post-processing */
|
|
// highlight-next-line
|
|
processData: false,
|
|
|
|
/* use the binary transport */
|
|
// highlight-next-line
|
|
dataType: "binary",
|
|
|
|
/* pass an ArrayBuffer in the callback */
|
|
// highlight-next-line
|
|
responseType: "arraybuffer",
|
|
|
|
success: function (ab) {
|
|
/* at this point, ab is an ArrayBuffer */
|
|
// highlight-next-line
|
|
var wb = XLSX.read(ab);
|
|
|
|
/* do something with workbook here */
|
|
var ws = wb.Sheets[wb.SheetNames[0]];
|
|
var html = XLSX.utils.sheet_to_html(ws);
|
|
$("#out").html(html);
|
|
}
|
|
});
|
|
```
|
|
|
|
### Wrapper Libraries
|
|
|
|
Before `fetch` shipped with browsers, there were various wrapper libraries to
|
|
simplify `XMLHttpRequest`. Due to limitations with `fetch`, these libraries
|
|
are still relevant.
|
|
|
|
#### axios
|
|
|
|
[`axios`](https://axios-http.com/) presents a Promise based interface. Setting
|
|
`responseType` to `arraybuffer` ensures the return type is an ArrayBuffer:
|
|
|
|
```js
|
|
async function workbook_dl_axios(url) {
|
|
const res = await axios(url, {responseType:'arraybuffer'});
|
|
const workbook = XLSX.read(res.data);
|
|
return workbook;
|
|
}
|
|
```
|
|
|
|
<details><summary><b>Live Download demo</b> (click to show)</summary>
|
|
|
|
This demo uses `axios` to download <https://sheetjs.com/pres.numbers> and show
|
|
the data in an HTML table.
|
|
|
|
:::caution pass
|
|
|
|
If the live demo shows a message
|
|
|
|
```
|
|
ReferenceError: axios is not defined
|
|
```
|
|
|
|
please refresh the page. This is a known bug in the documentation generator.
|
|
|
|
:::
|
|
|
|
```jsx live
|
|
function SheetJSAxiosDL() {
|
|
const [__html, setHTML] = React.useState("");
|
|
|
|
/* Fetch and update HTML */
|
|
React.useEffect(async() => {
|
|
if(typeof axios != "function") return setHTML("ReferenceError: axios is not defined");
|
|
/* Fetch file */
|
|
const res = await axios("https://sheetjs.com/pres.numbers", {responseType: "arraybuffer"});
|
|
|
|
/* Parse file */
|
|
const wb = XLSX.read(res.data);
|
|
const ws = wb.Sheets[wb.SheetNames[0]];
|
|
|
|
/* Generate HTML */
|
|
setHTML(XLSX.utils.sheet_to_html(ws));
|
|
}, []);
|
|
|
|
return ( <div dangerouslySetInnerHTML={{ __html }}/> );
|
|
}
|
|
```
|
|
|
|
</details>
|
|
|
|
#### superagent
|
|
|
|
[`superagent`](https://github.com/visionmedia/superagent) is a network request
|
|
library with a "Fluent Interface". Calling the `responseType` method with
|
|
`"arraybuffer"` will ensure the final response object is an `ArrayBuffer`:
|
|
|
|
```js
|
|
/* set up an async GET request with superagent */
|
|
superagent
|
|
.get(url)
|
|
.responseType('arraybuffer')
|
|
.end(function(err, res) {
|
|
/* parse the data when it is received */
|
|
var data = new Uint8Array(res.body);
|
|
var workbook = XLSX.read(data, {type:"array"});
|
|
|
|
/* DO SOMETHING WITH workbook HERE */
|
|
});
|
|
```
|
|
|
|
<details><summary><b>Live Download demo</b> (click to show)</summary>
|
|
|
|
This demo uses `superagent` to download <https://sheetjs.com/pres.numbers> and
|
|
show the data in an HTML table.
|
|
|
|
:::caution pass
|
|
|
|
If the live demo shows a message
|
|
|
|
```
|
|
ReferenceError: superagent is not defined
|
|
```
|
|
|
|
please refresh the page. This is a known bug in the documentation generator.
|
|
|
|
:::
|
|
|
|
```jsx live
|
|
function SheetJSSuperAgentDL() {
|
|
const [__html, setHTML] = React.useState("");
|
|
|
|
/* Fetch and update HTML */
|
|
React.useEffect(async() => {
|
|
if(typeof superagent == "undefined" || typeof superagent.get != "function")
|
|
return setHTML("ReferenceError: superagent is not defined");
|
|
/* Fetch file */
|
|
superagent
|
|
.get("https://sheetjs.com/pres.numbers")
|
|
.responseType("arraybuffer")
|
|
.end((err, res) => {
|
|
/* Parse file */
|
|
const wb = XLSX.read(res.body);
|
|
const ws = wb.Sheets[wb.SheetNames[0]];
|
|
|
|
/* Generate HTML */
|
|
setHTML(XLSX.utils.sheet_to_html(ws));
|
|
});
|
|
}, []);
|
|
|
|
return ( <div dangerouslySetInnerHTML={{ __html }}/> );
|
|
}
|
|
```
|
|
|
|
</details>
|
|
|
|
## NodeJS Demos
|
|
|
|
These examples show how to download data in NodeJS.
|
|
|
|
### HTTPS GET
|
|
|
|
The `https` module provides a low-level `get` method for HTTPS GET requests:
|
|
|
|
```js title="SheetJSHTTPSGet.js"
|
|
var https = require("https"), XLSX = require("xlsx");
|
|
|
|
https.get('https://sheetjs.com/pres.numbers', function(res) {
|
|
var bufs = [];
|
|
res.on('data', function(chunk) { bufs.push(chunk); });
|
|
res.on('end', function() {
|
|
var buf = Buffer.concat(bufs);
|
|
var wb = XLSX.read(buf);
|
|
/* print the first worksheet to console */
|
|
var ws = wb.Sheets[wb.SheetNames[0]];
|
|
console.log(XLSX.utils.sheet_to_csv(ws));
|
|
});
|
|
});
|
|
```
|
|
|
|
<details><summary><b>Complete Example</b> (click to show)</summary>
|
|
|
|
:::note
|
|
|
|
This demo was last tested on 2023 August 29 against NodeJS `20.5.1`
|
|
|
|
:::
|
|
|
|
1) Install the [NodeJS module](/docs/getting-started/installation/nodejs)
|
|
|
|
<CodeBlock language="bash">{`\
|
|
npm i --save https://cdn.sheetjs.com/xlsx-${current}/xlsx-${current}.tgz`}
|
|
</CodeBlock>
|
|
|
|
2) Copy the `SheetJSHTTPSGet.js` code snippet to a file `SheetJSHTTPSGet.js`
|
|
|
|
3) Run `node SheetJSHTTPSGet.js`. It will print CSV contents of the test file.
|
|
|
|
</details>
|
|
|
|
### fetch
|
|
|
|
The `fetch` implementation has the same return types as the browser version:
|
|
|
|
```js
|
|
async function parse_from_url(url) {
|
|
const res = await fetch(url);
|
|
if(!res.ok) throw new Error("fetch failed");
|
|
const ab = await res.arrayBuffer();
|
|
const workbook = XLSX.read(ab);
|
|
return workbook;
|
|
}
|
|
```
|
|
|
|
<details><summary><b>Complete Example</b> (click to show)</summary>
|
|
|
|
:::note
|
|
|
|
This demo was last tested on 2023 August 29 against NodeJS `20.5.1`
|
|
|
|
:::
|
|
|
|
1) Install the [NodeJS module](/docs/getting-started/installation/nodejs)
|
|
|
|
<CodeBlock language="bash">{`\
|
|
npm i --save https://cdn.sheetjs.com/xlsx-${current}/xlsx-${current}.tgz`}
|
|
</CodeBlock>
|
|
|
|
2) Save the following to `SheetJSFetch.js`:
|
|
|
|
```js title="SheetJSFetch.js"
|
|
var XLSX = require("xlsx");
|
|
|
|
async function parse_from_url(url) {
|
|
const res = await fetch(url);
|
|
if(!res.ok) throw new Error("fetch failed");
|
|
const ab = await res.arrayBuffer();
|
|
const workbook = XLSX.read(ab);
|
|
return workbook;
|
|
}
|
|
|
|
(async() => {
|
|
const wb = await parse_from_url('https://sheetjs.com/pres.numbers');
|
|
/* print the first worksheet to console */
|
|
var ws = wb.Sheets[wb.SheetNames[0]];
|
|
console.log(XLSX.utils.sheet_to_csv(ws));
|
|
})();
|
|
```
|
|
|
|
3) Run `node SheetJSFetch.js`. It will print CSV contents of the test file.
|
|
|
|
</details>
|
|
|
|
### Wrapper Libraries
|
|
|
|
The latest releases of NodeJS support `fetch` natively. Before `fetch` support
|
|
was added to the platform, third party modules wrapped the native APIs.
|
|
|
|
#### request
|
|
|
|
:::warning pass
|
|
|
|
`request` has been deprecated and should only be used in legacy deployments.
|
|
|
|
:::
|
|
|
|
Setting the option `encoding: null` passes raw buffers:
|
|
|
|
```js title="SheetJSRequest.js"
|
|
var XLSX = require('xlsx'), request = require('request');
|
|
var url = 'https://sheetjs.com/pres.numbers';
|
|
|
|
/* call `request` with the option `encoding: null` */
|
|
// highlight-next-line
|
|
request(url, {encoding: null}, function(err, res, data) {
|
|
if(err || res.statusCode !== 200) return;
|
|
|
|
/* if the request was successful, parse the data */
|
|
// highlight-next-line
|
|
var wb = XLSX.read(data);
|
|
|
|
/* print the first worksheet to console */
|
|
var ws = wb.Sheets[wb.SheetNames[0]];
|
|
console.log(XLSX.utils.sheet_to_csv(ws));
|
|
});
|
|
```
|
|
|
|
<details><summary><b>Complete Example</b> (click to show)</summary>
|
|
|
|
:::note
|
|
|
|
This demo was last tested on 2023 August 29 against request `2.88.2`
|
|
|
|
:::
|
|
|
|
1) Install the [NodeJS module](/docs/getting-started/installation/nodejs)
|
|
|
|
<CodeBlock language="bash">{`\
|
|
npm i --save https://cdn.sheetjs.com/xlsx-${current}/xlsx-${current}.tgz request@2.88.2`}
|
|
</CodeBlock>
|
|
|
|
2) Copy the `SheetJSRequest.js` code snippet to a file `SheetJSRequest.js`
|
|
|
|
3) Run `node SheetJSRequest.js`. It will print CSV contents of the test file.
|
|
|
|
</details>
|
|
|
|
#### axios
|
|
|
|
When the `responseType` is `"arraybuffer"`, `axios` actually captures the data
|
|
in a NodeJS Buffer. `XLSX.read` will transparently handle Buffers:
|
|
|
|
```js title="SheetJSAxios.js"
|
|
const XLSX = require("xlsx"), axios = require("axios");
|
|
|
|
async function workbook_dl_axios(url) {
|
|
const res = await axios(url, {responseType:'arraybuffer'});
|
|
/* at this point, res.data is a Buffer */
|
|
const workbook = XLSX.read(res.data);
|
|
return workbook;
|
|
}
|
|
```
|
|
|
|
<details><summary><b>Complete Example</b> (click to show)</summary>
|
|
|
|
:::note
|
|
|
|
This demo was last tested on 2023 August 29 against Axios `1.5.0`
|
|
|
|
:::
|
|
|
|
1) Install the [NodeJS module](/docs/getting-started/installation/nodejs)
|
|
|
|
<CodeBlock language="bash">{`\
|
|
npm i --save https://cdn.sheetjs.com/xlsx-${current}/xlsx-${current}.tgz axios@1.5.0`}
|
|
</CodeBlock>
|
|
|
|
2) Save the following to `SheetJSAxios.js`:
|
|
|
|
```js title="SheetJSAxios.js"
|
|
const XLSX = require("xlsx"), axios = require("axios");
|
|
|
|
async function workbook_dl_axios(url) {
|
|
const res = await axios(url, {responseType:'arraybuffer'});
|
|
/* at this point, res.data is a Buffer */
|
|
const workbook = XLSX.read(res.data);
|
|
return workbook;
|
|
}
|
|
|
|
(async() => {
|
|
const wb = await workbook_dl_axios('https://sheetjs.com/pres.numbers');
|
|
/* print the first worksheet to console */
|
|
var ws = wb.Sheets[wb.SheetNames[0]];
|
|
console.log(XLSX.utils.sheet_to_csv(ws));
|
|
})();
|
|
```
|
|
|
|
3) Run `node SheetJSAxios.js`. It will print CSV contents of the test file.
|
|
|
|
</details>
|
|
|
|
## Other Platforms
|
|
|
|
Other demos show network operations in special platforms:
|
|
|
|
- [React Native "Fetching Remote Data"](/docs/demos/mobile/reactnative#fetching-remote-data)
|
|
- [NativeScript "Fetching Remote Files"](/docs/demos/mobile/nativescript#fetching-remote-files)
|
|
|
|
[^1]: See [`read` in "Reading Files"](/docs/api/parse-options)
|
|
[^2]: See [`sheet_to_html` in "Utilities"](/docs/api/utilities/html#html-table-output)
|
|
[^3]: See [`dataType` in `jQuery.ajax`](https://api.jquery.com/jQuery.ajax/) in the official jQuery documentation.
|
|
[^4]: See [the official `jquery.binarytransport.js` repo](https://github.com/henrya/js-jquery/tree/master/BinaryTransport) for more details.
|