## Parsing Workbooks
For parsing, the first step is to read the file. This involves acquiring the
data and feeding it into the library. Here are a few common scenarios:
nodejs read a file (click to show)
`readFile` is only available in server environments. Browsers have no API for
reading arbitrary files given a path, so another strategy must be used.
```js
if(typeof require !== 'undefined') XLSX = require('xlsx');
var workbook = XLSX.readFile('test.xlsx');
/* DO SOMETHING WITH workbook HERE */
```
Browser read TABLE element from page (click to show)
The `table_to_book` and `table_to_sheet` utility functions take a DOM TABLE
element and iterate through the child nodes.
```js
var worksheet = XLSX.utils.table_to_book(document.getElementById('tableau'));
/* DO SOMETHING WITH workbook HERE */
```
Alternatively, the HTML code can be extracted and parsed:
```js
var htmlstr = document.getElementById('tableau').outerHTML;
var worksheet = XLSX.read(htmlstr, {type:'string'});
```
Browser download file (ajax) (click to show)
Note: for a more complete example that works in older browsers, check the demo
at ). The directory also
includes more examples with `XMLHttpRequest` and `fetch`.
```js
var url = "http://oss.sheetjs.com/test_files/formula_stress_test.xlsx";
/* set up async GET request */
var req = new XMLHttpRequest();
req.open("GET", url, true);
req.responseType = "arraybuffer";
req.onload = function(e) {
var data = new Uint8Array(req.response);
var workbook = XLSX.read(data, {type:"array"});
/* DO SOMETHING WITH workbook HERE */
}
req.send();
```
Browser drag-and-drop (click to show)
Drag-and-drop uses the HTML5 `FileReader` API, loading the data with
`readAsBinaryString` or `readAsArrayBuffer`. Since not all browsers support the
full `FileReader` API, dynamic feature tests are highly recommended.
```js
var rABS = true; // true: readAsBinaryString ; false: readAsArrayBuffer
function handleDrop(e) {
e.stopPropagation(); e.preventDefault();
var files = e.dataTransfer.files, f = files[0];
var reader = new FileReader();
reader.onload = function(e) {
var data = e.target.result;
if(!rABS) data = new Uint8Array(data);
var workbook = XLSX.read(data, {type: rABS ? 'binary' : 'array'});
/* DO SOMETHING WITH workbook HERE */
};
if(rABS) reader.readAsBinaryString(f); else reader.readAsArrayBuffer(f);
}
drop_dom_element.addEventListener('drop', handleDrop, false);
```
Browser file upload form element (click to show)
Data from file input elements can be processed using the same `FileReader` API
as in the drag-and-drop example:
```js
var rABS = true; // true: readAsBinaryString ; false: readAsArrayBuffer
function handleFile(e) {
var files = e.target.files, f = files[0];
var reader = new FileReader();
reader.onload = function(e) {
var data = e.target.result;
if(!rABS) data = new Uint8Array(data);
var workbook = XLSX.read(data, {type: rABS ? 'binary' : 'array'});
/* DO SOMETHING WITH workbook HERE */
};
if(rABS) reader.readAsBinaryString(f); else reader.readAsArrayBuffer(f);
}
input_dom_element.addEventListener('change', handleFile, false);
```
### Parsing Examples
- HTML5 File API / Base64 Text / Web Workers
Note that older versions of IE do not support HTML5 File API, so the Base64 mode
is used for testing.
Get Base64 encoding on OSX / Windows (click to show)
On OSX you can get the Base64 encoding with:
```bash
$ certutil -encode target_file target_file.b64
```
(note: You have to open the file and remove the header and footer lines)
- XMLHttpRequest