Refactor spellchecker class into backend subclasses for better extensibility

Thomas Bruederli

2013-10-11 bc0a470157518e5c5873872388280fbd711edc6e

 program/lib/Roundcube/rcube_spellchecker.php

@@ -3,8 +3,8 @@
/*
 +-----------------------------------------------------------------------+
 | This file is part of the Roundcube Webmail client                     |
 | Copyright (C) 2011, Kolab Systems AG                                  |
 | Copyright (C) 2008-2011, The Roundcube Dev Team                       |
 | Copyright (C) 2011-2013, Kolab Systems AG                             |
 | Copyright (C) 2008-2013, The Roundcube Dev Team                       |
 |                                                                       |
 | Licensed under the GNU General Public License version 3 or            |
 | any later version with exceptions for skins & plugins.                |
@@ -28,19 +28,13 @@
{
    private $matches = array();
    private $engine;
    private $backend;
    private $lang;
    private $rc;
    private $error;
    private $separator = '/[\s\r\n\t\(\)\/\[\]{}<>\\"]+|[:;?!,\.](?=\W|$)/';
    private $options = array();
    private $dict;
    private $have_dict;


    // default settings
    const GOOGLE_HOST = 'ssl://www.google.com';
    const GOOGLE_PORT = 443;
    const MAX_SUGGESTIONS = 10;


    /**
@@ -60,6 +54,15 @@
            'ignore_caps' => $this->rc->config->get('spellcheck_ignore_caps'),
            'dictionary'  => $this->rc->config->get('spellcheck_dictionary'),
        );

        $cls = 'rcube_spellcheck_' . $this->engine;
        if (class_exists($cls)) {
            $this->backend = new $cls($this, $this->lang);
            $this->backend->options = $this->options;
        }
        else {
            $this->error = "Unknown spellcheck engine '$this->engine'";
        }
    }


@@ -81,14 +84,8 @@
            $this->content = $text;
        }

        if ($this->engine == 'pspell') {
            $this->matches = $this->_pspell_check($this->content);
        }
        else if ($this->engine == 'enchant') {
            $this->matches = $this->_enchant_check($this->content);
        }
        else {
            $this->matches = $this->_googie_check($this->content);
        if ($this->backend) {
            $this->matches = $this->backend->check($this->content);
        }

        return $this->found() == 0;
@@ -115,14 +112,11 @@
     */
    function get_suggestions($word)
    {
        if ($this->engine == 'pspell') {
            return $this->_pspell_suggestions($word);
        }
        else if ($this->engine == 'enchant') {
            return $this->_enchant_suggestions($word);
        if ($this->backend) {
            return $this->backend->get_suggestions($word);
        }

        return $this->_googie_suggestions($word);
        return array();
    }


@@ -136,14 +130,15 @@
     */
    function get_words($text = null, $is_html=false)
    {
        if ($this->engine == 'pspell') {
            return $this->_pspell_words($text, $is_html);
        }
        else if ($this->engine == 'enchant') {
            return $this->_enchant_words($text, $is_html);
        if ($is_html) {
            $text = $this->html2text($text);
        }

        return $this->_googie_words($text, $is_html);
        if ($this->backend) {
            return $this->backend->get_words($text);
        }

        return array();
    }


@@ -199,394 +194,7 @@
     */
    function error()
    {
        return $this->error;
    }


    /**
     * Checks the text using pspell
     *
     * @param string $text Text content for spellchecking
     */
    private function _pspell_check($text)
    {
        // init spellchecker
        $this->_pspell_init();

        if (!$this->plink) {
            return array();
        }

        // tokenize
        $text = preg_split($this->separator, $text, NULL, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_OFFSET_CAPTURE);

        $diff       = 0;
        $matches    = array();

        foreach ($text as $w) {
            $word = trim($w[0]);
            $pos  = $w[1] - $diff;
            $len  = mb_strlen($word);

            // skip exceptions
            if ($this->is_exception($word)) {
            }
            else if (!pspell_check($this->plink, $word)) {
                $suggestions = pspell_suggest($this->plink, $word);

                if (sizeof($suggestions) > self::MAX_SUGGESTIONS) {
                    $suggestions = array_slice($suggestions, 0, self::MAX_SUGGESTIONS);
                }

                $matches[] = array($word, $pos, $len, null, $suggestions);
            }

            $diff += (strlen($word) - $len);
        }

        return $matches;
    }


    /**
     * Returns the misspelled words
     */
    private function _pspell_words($text = null, $is_html=false)
    {
        $result = array();

        if ($text) {
            // init spellchecker
            $this->_pspell_init();

            if (!$this->plink) {
                return array();
            }

            // With PSpell we don't need to get suggestions to return misspelled words
            if ($is_html) {
                $text = $this->html2text($text);
            }

            $text = preg_split($this->separator, $text, NULL, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_OFFSET_CAPTURE);

            foreach ($text as $w) {
                $word = trim($w[0]);

                // skip exceptions
                if ($this->is_exception($word)) {
                    continue;
                }

                if (!pspell_check($this->plink, $word)) {
                    $result[] = $word;
                }
            }

            return $result;
        }

        foreach ($this->matches as $m) {
            $result[] = $m[0];
        }

        return $result;
    }


    /**
     * Returns suggestions for misspelled word
     */
    private function _pspell_suggestions($word)
    {
        // init spellchecker
        $this->_pspell_init();

        if (!$this->plink) {
            return array();
        }

        $suggestions = pspell_suggest($this->plink, $word);

        if (sizeof($suggestions) > self::MAX_SUGGESTIONS)
            $suggestions = array_slice($suggestions, 0, self::MAX_SUGGESTIONS);

        return is_array($suggestions) ? $suggestions : array();
    }


    /**
     * Initializes PSpell dictionary
     */
    private function _pspell_init()
    {
        if (!$this->plink) {
            if (!extension_loaded('pspell')) {
                $this->error = "Pspell extension not available";
                return;
            }

            $this->plink = pspell_new($this->lang, null, null, RCUBE_CHARSET, PSPELL_FAST);
        }

        if (!$this->plink) {
            $this->error = "Unable to load Pspell engine for selected language";
        }
    }


    /**
     * Checks the text using enchant
     *
     * @param string $text Text content for spellchecking
     */
    private function _enchant_check($text)
    {
        // init spellchecker
        $this->_enchant_init();

        if (!$this->enchant_dictionary) {
            return array();
        }

        // tokenize
        $text = preg_split($this->separator, $text, NULL, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_OFFSET_CAPTURE);

        $diff       = 0;
        $matches    = array();

        foreach ($text as $w) {
            $word = trim($w[0]);
            $pos  = $w[1] - $diff;
            $len  = mb_strlen($word);

            // skip exceptions
            if ($this->is_exception($word)) {
            }
            else if (!enchant_dict_check($this->enchant_dictionary, $word)) {
                $suggestions = enchant_dict_suggest($this->enchant_dictionary, $word);

                if (sizeof($suggestions) > self::MAX_SUGGESTIONS) {
                    $suggestions = array_slice($suggestions, 0, self::MAX_SUGGESTIONS);
                }

                $matches[] = array($word, $pos, $len, null, $suggestions);
            }

            $diff += (strlen($word) - $len);
        }

        return $matches;
    }


    /**
     * Returns the misspelled words
     */
    private function _enchant_words($text = null, $is_html=false)
    {
        $result = array();

        if ($text) {
            // init spellchecker
            $this->_enchant_init();

            if (!$this->enchant_dictionary) {
                return array();
            }

            // With Enchant we don't need to get suggestions to return misspelled words
            if ($is_html) {
                $text = $this->html2text($text);
            }

            $text = preg_split($this->separator, $text, NULL, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_OFFSET_CAPTURE);

            foreach ($text as $w) {
                $word = trim($w[0]);

                // skip exceptions
                if ($this->is_exception($word)) {
                    continue;
                }

                if (!enchant_dict_check($this->enchant_dictionary, $word)) {
                    $result[] = $word;
                }
            }

            return $result;
        }

        foreach ($this->matches as $m) {
            $result[] = $m[0];
        }

        return $result;
    }


    /**
     * Returns suggestions for misspelled word
     */
    private function _enchant_suggestions($word)
    {
        // init spellchecker
        $this->_enchant_init();

        if (!$this->enchant_dictionary) {
            return array();
        }

        $suggestions = enchant_dict_suggest($this->enchant_dictionary, $word);

        if (sizeof($suggestions) > self::MAX_SUGGESTIONS)
            $suggestions = array_slice($suggestions, 0, self::MAX_SUGGESTIONS);

        return is_array($suggestions) ? $suggestions : array();
    }


    /**
     * Initializes PSpell dictionary
     */
    private function _enchant_init()
    {
        if (!$this->enchant_broker) {
            if (!extension_loaded('enchant')) {
                $this->error = "Enchant extension not available";
                return;
            }

            $this->enchant_broker = enchant_broker_init();
        }

        if (!enchant_broker_dict_exists($this->enchant_broker, $this->lang)) {
            $this->error = "Unable to load dictionary for selected language using Enchant";
            return;
        }

        $this->enchant_dictionary = enchant_broker_request_dict($this->enchant_broker, $this->lang);
    }


    private function _googie_check($text)
    {
        // spell check uri is configured
        $url = $this->rc->config->get('spellcheck_uri');

        if ($url) {
            $a_uri = parse_url($url);
            $ssl   = ($a_uri['scheme'] == 'https' || $a_uri['scheme'] == 'ssl');
            $port  = $a_uri['port'] ? $a_uri['port'] : ($ssl ? 443 : 80);
            $host  = ($ssl ? 'ssl://' : '') . $a_uri['host'];
            $path  = $a_uri['path'] . ($a_uri['query'] ? '?'.$a_uri['query'] : '') . $this->lang;
        }
        else {
            $host = self::GOOGLE_HOST;
            $port = self::GOOGLE_PORT;
            $path = '/tbproxy/spell?lang=' . $this->lang;
        }

        // Google has some problem with spaces, use \n instead
        $gtext = str_replace(' ', "\n", $text);

        $gtext = '<?xml version="1.0" encoding="utf-8" ?>'
            .'<spellrequest textalreadyclipped="0" ignoredups="0" ignoredigits="1" ignoreallcaps="1">'
            .'<text>' . $gtext . '</text>'
            .'</spellrequest>';

        $store = '';
        if ($fp = fsockopen($host, $port, $errno, $errstr, 30)) {
            $out = "POST $path HTTP/1.0\r\n";
            $out .= "Host: " . str_replace('ssl://', '', $host) . "\r\n";
            $out .= "Content-Length: " . strlen($gtext) . "\r\n";
            $out .= "Content-Type: application/x-www-form-urlencoded\r\n";
            $out .= "Connection: Close\r\n\r\n";
            $out .= $gtext;
            fwrite($fp, $out);

            while (!feof($fp))
                $store .= fgets($fp, 128);
            fclose($fp);
        }

        // parse HTTP response
        if (preg_match('!^HTTP/1.\d (\d+)(.+)!', $store, $m)) {
            $http_status = $m[1];
            if ($http_status != '200')
                $this->error = 'HTTP ' . $m[1] . $m[2];
        }

        if (!$store) {
            $this->error = "Empty result from spelling engine";
        }
        else if (preg_match('/<spellresult error="([^"]+)"/', $store, $m) && $m[1]) {
            $this->error = "Error code $m[1] returned";
        }

        preg_match_all('/<c o="([^"]*)" l="([^"]*)" s="([^"]*)">([^<]*)<\/c>/', $store, $matches, PREG_SET_ORDER);

        // skip exceptions (if appropriate options are enabled)
        if (!empty($this->options['ignore_syms']) || !empty($this->options['ignore_nums'])
            || !empty($this->options['ignore_caps']) || !empty($this->options['dictionary'])
        ) {
            foreach ($matches as $idx => $m) {
                $word = mb_substr($text, $m[1], $m[2], RCUBE_CHARSET);
                // skip  exceptions
                if ($this->is_exception($word)) {
                    unset($matches[$idx]);
                }
            }
        }

        return $matches;
    }


    private function _googie_words($text = null, $is_html=false)
    {
        if ($text) {
            if ($is_html) {
                $text = $this->html2text($text);
            }

            $matches = $this->_googie_check($text);
        }
        else {
            $matches = $this->matches;
            $text    = $this->content;
        }

        $result = array();

        foreach ($matches as $m) {
            $result[] = mb_substr($text, $m[1], $m[2], RCUBE_CHARSET);
        }

        return $result;
    }


    private function _googie_suggestions($word)
    {
        if ($word) {
            $matches = $this->_googie_check($word);
        }
        else {
            $matches = $this->matches;
        }

        if ($matches[0][4]) {
            $suggestions = explode("\t", $matches[0][4]);
            if (sizeof($suggestions) > self::MAX_SUGGESTIONS) {
                $suggestions = array_slice($suggestions, 0, MAX_SUGGESTIONS);
            }

            return $suggestions;
        }

        return array();
        return $this->error ? $this->error : ($this->backend ? $this->backend->error() : false);
    }