Simple HTML parser

Minimalistic HTML parser.

Note

If you need advanced DOM manipulation, consider using kuria/dom instead.

Contents

• Features
• Requirements
• Usage
  • Creating the parser
  • Iterating elements
  • Element array structure
    • Element types
  • Tag name and attribute normalization
  • Managing parser state
  • getHtml() - get HTML content
  • getSlice() - get part of the HTML
  • getSliceBetween() - get content between 2 elements
  • getLength() - get length of the HTML
  • getEncoding() - determine encoding of the HTML document
  • getEncodingTag() - find the encoding-specifying meta tag
  • usesFallbackEncoding() - see if the fallback encoding is being used
  • setFallbackEncoding() - set fallback encoding
  • getDoctypeElement() - find the doctype element
  • escape() - escape a string
  • find() - match a specific element
  • getOffset() - get current offset
• Example: Reading document's title

Features

• parsing opening tags
• parsing closing tags
• parsing comments
• parsing DTDs
• extracting parts of HTML content
• determining encoding of HTML documents
• handling "raw text" tags (<style>, <script>, <noscript>, etc.)

Requirements

• PHP 7.1+

Usage

Creating the parser

<?php

use Kuria\SimpleHtmlParser\SimpleHtmlParser;

$parser = new SimpleHtmlParser($html);

Iterating elements

The parser implements Iterator so it can be traversed using the standard iterator methods.

<?php

foreach ($parser as $element) {
    print_r($element);
}

<?php

$parser->rewind();

if ($parser->valid()) {
    print_r($parser->current());
}

Element array structure

Each element is an array with the following keys. Some keys are available only for specific element types.

Key	Types	Description
type	any	The type of the element, see Element types
start	any	Byte offset at which the element begins
end	any	Byte offset at which the element ends
name	SimpleHtmlParser::OPENING_TAG, SimpleHtmlParser::CLOSING_TAG	Tag name (e.g. div), see Tag name and attribute normalization
attrs	SimpleHtmlParser::OPENING_TAG	Array with the opening tag's attributes, see Tag name and attribute normalization
symbol	SimpleHtmlParser::OTHER	!, ? or /

Element types

• SimpleHtmlParser::COMMENT - a comment, e.g. <!-- foo -->
• SimpleHtmlParser::OPENING_TAG - an opening tag, e.g. <span class="bar">
• SimpleHtmlParser::CLOSING_TAG - a closing tag, e.g. </span>
• SimpleHtmlParser::OTHER - special element, e.g. doctype, XML header
• SimpleHtmlParser::INVALID - invalid or incomplete tags

Tag name and attribute normalization

Tag and attribute names that contain only ASCII characters are lowercased.

Managing parser state

The state methods can be used to temporarily store and/or revert state of the parser.

• pushState() - push current state of the parser onto the stack
• popState() - pop (discard) state stored on top of the stack
• revertState() - pop and restore state stored on top of the stack
• countStates() - count the number of states currently on the stack
• clearStates() - discard all states

getHtml() - get HTML content

The getHtml() method may be used to get the entire HTML content or HTML of a single element.

<?php

$parser->getHtml(); // get entire document
$parser->getHtml($element); // get single element

getSlice() - get part of the HTML

The getSlice() method returns a part of the HTML content.

Returns an empty string for negative or out-of-bounds ranges.

<?php

$slice = $parser->getSlice(100, 200);

getSliceBetween() - get content between 2 elements

The getSliceBetween() method returns a part of the HTML content that is between 2 elements (usually opening and closing tag).

<?php

$slice = $parser->getSliceBetween($openingTag, $closingTag);

getLength() - get length of the HTML

The getLength() returns total length of the HTML content.

getEncoding() - determine encoding of the HTML document

The getEncoding() method attempts to determine encoding of the HTML document.

If the encoding cannot be determined or is not supported, the fallback encoding will be used instead.

This method does not alter the parser's state.

getEncodingTag() - find the encoding-specifying meta tag

The getEncodingTag() method attempts to find the <meta charset="..."> or <meta http-equiv="Content-Type" content="..."> tag in the first 1024 bytes of the HTML document.

Returns NULL if the tag was not found.

This method does not alter the parser's state.

usesFallbackEncoding() - see if the fallback encoding is being used

The usesFallbackEncoding() indicates whether the fallback encoding is being used. This is the case when the encoding is not specified or is not supported.

This method does not alter the parser's state.

setFallbackEncoding() - set fallback encoding

The setFallbackEncoding() method specifies an encoding to be used in case the document has no encoding specified or specifies an unsupported encoding.

The fallback encoding must be supported by htmlspecialchars().

getDoctypeElement() - find the doctype element

The getDoctypeElement() method attempts to find the doctype in the first 1024 bytes of the HTML document.

Returns NULL if no doctype was found.

escape() - escape a string

The escape() method escapes a string using htmlspecialchars() using the HTML document's encoding.

find() - match a specific element

The find() method attempts to find a specific element starting from the current position, optionally stopping after a given number of bytes.

Returns NULL if no element was matched.

<?php

$element = $parser->find(SimpleHtmlParser::OPENING_TAG, 'title');

getOffset() - get current offset

The getOffset() method returns the current parser offset in bytes.

Example: Reading document's title

<?php

$html = <<<HTML
<!doctype html>
<meta charset="utf-8">
<title>Foo bar</title>
<h1>Baz qux</h1>
HTML;

$parser = new SimpleHtmlParser($html);

$titleOpen = $parser->find(SimpleHtmlParser::OPENING_TAG, 'title');

if ($titleOpen) {
    $titleClose = $parser->find(SimpleHtmlParser::CLOSING_TAG, 'title');

    if ($titleClose) {
        $title = $parser->getSliceBetween($titleOpen, $titleClose);

        var_dump($title);
    }
}

Output:

string(7) "Foo bar"