# Class: ParserStream
Streaming HTML parser with scripting support. A [writable stream](https://nodejs.org/api/stream.html#stream_class_stream_writable).
*__example__*:
```js
const ParserStream = require('parse5-parser-stream');
const http = require('http');
// Fetch the page content and obtain it's node
http.get('http://inikulin.github.io/parse5/', res => {
const parser = new ParserStream();
parser.once('finish', () => {
console.log(parser.document.childNodes[1].childNodes[0].tagName); //> 'head'
});
res.pipe(parser);
});
```
### Constructors
* [constructor](#constructor)
### Properties
* [document](#document)
### Methods
See: [writable stream API](https://nodejs.org/api/stream.html#stream_class_stream_writable).
### Events
* [on("script")](#on_script)
Also see: [writable stream API](https://nodejs.org/api/stream.html#stream_class_stream_writable).
---
## Constructors
### constructor
⊕ **new ParserStream**(options?: *[ParserOptions](../../parse5/docs/options/parser-options.md)*): [ParserStream]()
**Parameters:**
| Param | Type | Description |
| ------ | ------ | ------ |
| `Optional` options | [ParserOptions](../../parse5/docs/options/parser-options.md) | Parsing options. |
**Returns:** [ParserStream]()
___
## Properties
### document
**● document**: *Document*
The resulting document node.
___
## Events
### on("script")
▸ **on**(event: *"script"*, listener: *`function`*): `this`
Raised when parser encounters a `');
```
**Parameters:**
| Param | Type |
| ------ | ------ |
| event | "script" |
| listener | `function` (see below) |
**Returns:** `this`
**listener:** (scriptElement: *Element*, documentWrite: *`function`*, resume: *`function`*): *`void`*
| Param | Type | Description |
| ------ | ------ | ------ |
| scriptElement | Element | The script element that caused the event. |
| documentWrite | `function (html: string): void` | Write additional html at the current parsing position. Suitable for implementing the DOM document.write and document.writeln methods. |
| resume | `function` | Resumes parsing.
___