Spiral\Stempler\HtmlTokenizer

Complexity

Total Complexity

41

Size/Duplication

Total Lines	334
Duplicated Lines	0 %

Coupling/Cohesion

Components	1
Dependencies	1

Importance

Changes

0

7 Methods

Rating	Name	Duplication	Size	Complexity
A	__construct()	0	5	2
C	parse()	0	75	15
A	compile()	0	9	2
B	compileToken()	0	28	6
C	parseToken()	0	69	11
A	handleToken()	0	17	3
A	repairPHP()	0	8	2

<?php
/**
 * Spiral Framework.
 *
 * @license   MIT
 * @author    Anton Titov (Wolfy-J)
 */
namespace Spiral\Stempler;

use Spiral\Tokenizer\Isolator;

/**
 * Perform html code tokenization. Class used for spiral Stempler and can be used for other html
 * related operations. HtmlTokenizer is pretty slow! Please don't forget that this is tokenizer,
 * not parser.
 *
 * @todo very old class, improvement is required
 */
class HtmlTokenizer
{
    /**
     * Current tokenizer position. Tokenizer is a linear processor (no regular expression is
     * involved). This slows it down, but the results are much more reliable.
     */
    const POSITION_PLAIN_TEXT = 0x001;
    const POSITION_IN_TAG     = 0x002;
    const POSITION_IN_QUOTAS  = 0x003;

    /**
     * Token types detected and processed by tokenizer.
     */
    const PLAIN_TEXT = 'plain';
    const TAG_OPEN   = 'open';
    const TAG_CLOSE  = 'close';
    const TAG_SHORT  = 'short';
    const TAG_VOID   = 'void';

    /**
     * Token fields. There are a lot of tokens in HTML (up to 10,000 different ones). We better to
     * use numeric keys for array than any text fields or even objects.
     */
    const TOKEN_NAME       = 0;
    const TOKEN_TYPE       = 1;
    const TOKEN_CONTENT    = 2;
    const TOKEN_ATTRIBUTES = 3;

    /**
     * List of void tags.
     *
     * @link http://www.w3.org/TR/html5/syntax.html#void-elements
     * @var array
     */
    protected $voidTags = [
        'area',
        'base',
        'br',
        'col',
        'embed',
        'hr',
        'img',
        'input',
        'keygen',
        'link',
        'meta',
        'param',
        'source',
        'track',
        'wbr'
    ];

    /**
     * Array of parsed tokens. Every token has fields name, type, content and arguments.
     *
     * @var array
     */
    protected $tokens = [];

    /**
     * PHP block should be isolated while parsing, Keep enabled.
     *
     * @var bool
     */
    protected $isolatePHP = false;

    /**
     * PHP Blocks isolator, which holds all existing PHP blocks and restores them in output.
     *
     * @var Isolator|null
     */
    protected $isolator = null;

    /**
     * @param bool     $isolatePHP PHP block should be isolated and enabled by default
     * @param Isolator $isolator
     */
    public function __construct(bool $isolatePHP = true, Isolator $isolator = null)
    {
        $this->isolatePHP = $isolatePHP;
        $this->isolator = !empty($isolator) ? $isolator : new Isolator();
    }

    /**
     * Parse HTML content and return it's tokens.
     *
     * @param string $source HTML source.
     *
     * @return array
     */
    public function parse(string $source): array
    {
        //Cleaning list of already parsed tokens
        $this->tokens = [];

        if ($this->isolatePHP) {
            $source = $this->isolator->isolatePHP($source);
        }

        $quotas = '';
        $buffer = '';

        $length = strlen($source);
        $position = self::POSITION_PLAIN_TEXT;
        for ($pointer = 0; $pointer < $length; $pointer++) {
            $char = $source[$pointer];
            switch ($char) {
                case '<':
                    if ($position == self::POSITION_IN_QUOTAS) {
                        $buffer .= $char;
                        break;
                    }

                    if ($position == self::POSITION_IN_TAG) {
                        $buffer = '<' . $buffer;
                    }

                    //Handling previous token
                    $this->handleToken(self::PLAIN_TEXT, $buffer);

                    //We are in tag now
                    $position = self::POSITION_IN_TAG;
                    $buffer = '';
                    break;
                case '>':
                    if ($position != self::POSITION_IN_TAG) {
                        $buffer .= $char;
                        break;
                    }

                    //Token ended
                    $this->handleToken(null, $buffer);

                    //We are in a plain text now
                    $position = self::POSITION_PLAIN_TEXT;
                    $buffer = '';
                    break;
                case '"':
                    //no break
                case "'":
                    if ($position == self::POSITION_IN_TAG) {
                        //Jumping into argument
                        $position = self::POSITION_IN_QUOTAS;
                        $quotas = $char;
                    } elseif ($position == self::POSITION_IN_QUOTAS && $char == $quotas) {
                        //Jumping from argument
                        $position = self::POSITION_IN_TAG;
                        $quotas = '';
                    }
                default:
                    //Checking for invalid characters in tag name or arguments
                    if ($position == self::POSITION_IN_TAG) {
                        if (!preg_match('/[a-z0-9 \._\-="\':\/\r\n\t]/i', $char)) {
                            $buffer = '<' . $buffer;
                            $position = self::POSITION_PLAIN_TEXT;
                        }
                    }
                    $buffer .= $char;
            }
        }

        $this->handleToken(self::PLAIN_TEXT, $buffer);

        return $this->tokens;
    }

    /**
     * Compile all parsed tokens back into html form.
     *
     * @return string
     */
    public function compile(): string
    {
        $result = '';
        foreach ($this->tokens as $token) {
            $result .= $this->compileToken($token);
        }

        return $result;
    }

    /**
     * Compile parsed token.
     *
     * @param array $token
     *
     * @return string
     */
    public function compileToken(array $token): string
    {
        if (in_array($token[self::TOKEN_TYPE], [self::PLAIN_TEXT, self::TAG_CLOSE])) {
            //Nothing to compile
            return $token[HtmlTokenizer::TOKEN_CONTENT];
        }

        $result = $token[HtmlTokenizer::TOKEN_NAME];
        $attributes = [];
        foreach ($token[self::TOKEN_ATTRIBUTES] as $attribute => $value) {
            if ($value === null) {
                $attributes[] = $attribute;
                continue;
            }

            $attributes[] = $attribute . '="' . $value . '"';
        }

        if (!empty($attributes)) {
            $result .= ' ' . join(' ', $attributes);
        }

        if ($token[HtmlTokenizer::TOKEN_TYPE] == HtmlTokenizer::TAG_SHORT) {
            $result .= '/';
        }

        return '<' . $result . '>';
    }

    /**
     * Parses tag body for arguments, name, etc.
     *
     * @param string $content Tag content to be parsed (from < till >).
     *
     * @return array
     */
    protected function parseToken(string $content): array
    {
        $token = [
            self::TOKEN_NAME       => '',
            self::TOKEN_TYPE       => self::TAG_OPEN,
            self::TOKEN_CONTENT    => '<' . ($content = $this->repairPHP($content)) . '>',
            self::TOKEN_ATTRIBUTES => []
        ];

        //Some parts of text just looks like tags, but their not
        if (!preg_match('/^\/?[a-z0-9_:\/][a-z 0-9\._\-:\/]*/i', $content)) {
            $token[self::TOKEN_TYPE] = self::PLAIN_TEXT;
            unset($token[self::TOKEN_NAME], $token[self::TOKEN_NAME]);

            return $token;
        }

        //Local PHP isolation
        $isolator = new Isolator('-argument-', '-block-', true);

The call to Isolator::__construct() has too many arguments starting with true.

        //No PHP blocks
        $content = $isolator->isolatePHP($content);

        //Parsing arguments, due they already checked for open-close quotas we can use regular expression
        $attribute = '/(?P<name>[a-z0-9_\-\.\:]+)[ \n\t\r]*(?:(?P<equal>=)[ \n\t\r]*'
            . '(?P<value>[a-z0-9\-]+|\'[^\']+\'|\"[^\"]+\"|\"\"))?/si';

        preg_match_all($attribute, $content, $attributes);

        foreach ($attributes['value'] as $index => $value) {
            if ($value && ($value{0} == "'" || $value{0} == '"')) {
                $value = trim($value, $value{0});
            }

            //Local and global php isolation restore
            $name = $this->repairPHP($isolator->repairPHP($attributes['name'][$index]));

            $token[self::TOKEN_ATTRIBUTES][$name] = $this->repairPHP($isolator->repairPHP($value));

            if (empty($attributes['equal'][$index])) {
                $token[self::TOKEN_ATTRIBUTES][$name] = null;
            }
        }

        //Fetching name
        $name = $isolator->repairPHP(current(explode(' ', $content)));
        if ($name{0} == '/') {
            $token[self::TOKEN_TYPE] = self::TAG_CLOSE;
            unset($token[self::TOKEN_ATTRIBUTES]);
        }

        if ($content{strlen($content) - 1} == '/') {
            $token[self::TOKEN_TYPE] = self::TAG_SHORT;
        }

        $token[self::TOKEN_NAME] = $name = trim($name, '/');
        unset($token[self::TOKEN_ATTRIBUTES][$name]);

        $token[self::TOKEN_NAME] = trim($token[self::TOKEN_NAME]);

        if (
            $token[self::TOKEN_TYPE] == self::TAG_OPEN
            && in_array($token[self::TOKEN_NAME], $this->voidTags)
        ) {
            $token[self::TOKEN_TYPE] = self::TAG_VOID;
        }

        return $token;
    }

    /**
     * Handles single token and passes it to a callback function if specified.
     *
     * @param int|null $tokenType Token type.
     * @param string   $content   Non parsed token content.
     */
    protected function handleToken($tokenType, string $content)
    {
        if ($tokenType == self::PLAIN_TEXT) {
            if (empty($content)) {
                return;
            }

            $token = [
                self::TOKEN_TYPE    => self::PLAIN_TEXT,
                self::TOKEN_CONTENT => $this->repairPHP($content)
            ];
        } else {
            $token = $this->parseToken($content);
        }

        $this->tokens[] = $token;
    }

    /**
     * Will restore all existing PHP blocks to their original content.
     *
     * @param string $source
     *
     * @return string
     */
    protected function repairPHP(string $source): string
    {
        if (!$this->isolatePHP) {
            return $source;
        }

        return $this->isolator->repairPHP($source);
    }
}