Solution to the Problem of Intercepting Garbled Characters in smarty Chinese and English Multi Coded Characters

This article describes the example of smarty Chinese and English multi-code character interception garbled problem solution, shared for everyone for your reference. The specific methods are as follows:

1. The display of website pages inevitably involves substring interception. At this time, truncate comes in handy, but it is only suitable for English users. For Chinese users, using truncate will cause garbled codes. For Chinese-English mixed strings, intercepting the same number of strings will actually display different lengths, which will appear uneven visually and affect the beauty. This is because the length of one Chinese is roughly equivalent to the length of two English. In addition, truncate is not compatible with GB2312, UTF-8 and other codes at the same time.
Improved smartTruncate: Filename: modifier. smartTruncate. php
The specific code is as follows:

<?php 

function smartDetectUTF8($string) 

{ 

    static $result = array();

    if(! array_key_exists($key = md5($string), $result)) 

    { 

        $utf8 = " 

            /^(?: 

                [\x09\x0A\x0D\x20-\x7E]                            # ASCII 

                | [\xC2-\xDF][\x80-\xBF]                             # non-overlong 2-byte 

                | \xE0[\xA0-\xBF][\x80-\xBF]                       # excluding overlongs 

                | [\xE1-\xEC\xEE\xEF][\x80-\xBF]{2}           # straight 3-byte 

                | \xED[\x80-\x9F][\x80-\xBF]                      # excluding surrogates 

                | \xF0[\x90-\xBF][\x80-\xBF]{2}                 # planes 1-3 

                | [\xF1-\xF3][\x80-\xBF]{3}                          # planes 4-15 

                | \xF4[\x80-\x8F][\x80-\xBF]{2}                  # plane 16 

            )+$/xs 

        ";

        $result[$key] = preg_match(trim($utf8), $string); 

    }

    return $result[$key]; 

}

function smartStrlen($string) 

{ 

    $result = 0;

    $number = smartDetectUTF8($string) ? 3 : 2;

    for($i = 0; $i < strlen($string); $i += $bytes) 

    { 

        $bytes = ord(substr($string, $i, 1)) > 127 ? $number : 1;

        $result += $bytes > 1 ? 1.0 : 0.5; 

    }

    return $result; 

}

function smartSubstr($string, $start, $length = null) 

{ 

    $result = '''';

    $number = smartDetectUTF8($string) ? 3 : 2;

    if($start < 0) 

    { 

        $start = max(smartStrlen($string) + $start, 0); 

    }

    for($i = 0; $i < strlen($string); $i += $bytes) 

    { 

        if($start <= 0) 

        { 

            break; 

        }

        $bytes = ord(substr($string, $i, 1)) > 127 ? $number : 1;

        $start -= $bytes > 1 ? 1.0 : 0.5; 

    }

    if(is_null($length)) 

    { 

        $result = substr($string, $i); 

    } 

    else 

    { 

        for($j = $i; $j < strlen($string); $j += $bytes) 

        { 

            if($length <= 0) 

            { 

                break; 

            }

            if(($bytes = ord(substr($string, $j, 1)) > 127 ? $number : 1) > 1) 

            { 

                if($length < 1.0) 

                { 

                    break; 

                }

                $result .= substr($string, $j, $bytes); 

                $length -= 1.0; 

            } 

            else 

            { 

                $result .= substr($string, $j, 1); 

                $length -= 0.5; 

            } 

        } 

    }

    return $result; 

}

function smarty_modifier_smartTruncate($string, $length = 80, $etc = ''...'', 

                                       $break_words = false, $middle = false) 

{ 

    if ($length == 0) 

        return '''';

    if (smartStrlen($string) > $length) { 

        $length -= smartStrlen($etc); 

        if (!$break_words && !$middle) { 

            $string = preg_replace(''/\s+?(\S+)?$/'', '''', smartSubstr($string, 0, $length+1)); 

        } 

        if(!$middle) { 

            return smartSubstr($string, 0, $length).$etc; 

        } else { 

            return smartSubstr($string, 0, $length/2) . $etc . smartSubstr($string, -$length/2); 

        } 

    } else { 

        return $string; 

    } 

} 

?>

The above code completely realizes the original functions of truncate, and can be compatible with GB2312 and UTF-8 coding at the same time. When judging the character length, one Chinese character is calculated as 1.0, and one English character is calculated as 0.5, so there will be no uneven situation when intercepting substrings.
There is nothing special about how the plug-in is used. Here is a simple test 1:

{$content|smartTruncate:5:".."} ( $content Equal to "A Medium B Hua C People D People E Altogether F And G Countries H" ) 

It shows that B in A is C... (the length of Chinese symbols is calculated as 1.0, the length of English symbols is calculated as 0.5, and the length of omitted symbols is considered)
Whether you encode GB2312 or UTF-8, you will find that the results are correct, which is one of the reasons why I added the word smart to the plug-in name.

I hope this article is helpful to everyone's PHP programming.