10c07-1.php

来自「介绍PHP5的给类型函数应用」· PHP 代码 · 共 75 行

<?php
// A function to format BBCode.  It current translates the following:
//   [b] = <b>,   [i] = <i>,   [code] = <pre>,
//   [quote] = <blockquote><i>,   [img] = <img>
// It also turns double-carraige returns, into appropriate whitespace
function format_bbcode($string) {
    // Define some direct translations:
    $trans = array( 'b' => 'b', 'i' => 'i', 'code' => 'pre' );
    
    // Using regex to find bbcode, and loop over the string:
    // It is necessary to loop, to handle code within code.
    // This regex looks for [word], followed by anything up to [/word]
    while (preg_match('|\[([a-z]+)\](.*?)\[/\1\]|', 
            $string, $r, PREG_OFFSET_CAPTURE)) {
        // So at this point [0][0] contains the full matched string.
        // [0][1] contains the offset position of that string
        // [1][0] is the second match, which is our tag name.
        // [2][0] is the 3rd match, the tag contents

        // So now, based upon the tag, implement the HTML
        
        // If this is a direct translation tag:
        if (isset($trans[$r[1][0]])) {
            // Simply replace with HTML tag version:
            $replace = "<{$trans[$r[1][0]]}>{$r[2][0]}</{$trans[$r[1][0]]}>";
        }
        // Special case: quote
        elseif ($r[1][0] == 'quote') {
            // Replace with two tags:
            $replace = "<blockquote><i>{$r[2][0]}</i></blockquote>";
        }
        // Special case: img
        elseif ($r[1][0] == 'img') {
            // Create an image tag using the contents.
            $replace = "<img src=\"{$r[2][0]}\" />";
        } else {
            // If we found any other tag, consider it invalid, and strip it:
            $replace = $r[2][0];
        }
        
        // Now, perform the actual replacement
        $string = substr_replace($string, $replace, $r[0][1], 
            strlen($r[0][0]));
    }
    
    // One last step, replace any double-carraige returns, with a 
    //  paragraph break, make it work for both Windows servers:
    $string = str_replace("\r\n\r\n", '</p><p>', $string);
    // And unix:
    $string = str_replace("\n\n", '</p><p>', $string);

    // Now return the whole string, surrounded by paragraph tags:
    return "<p>{$string}</p>";
}

// If we had a POST, then output the data for reference:
if (count($_POST)) {
    // Strip the data of special characters, and then BBCode it:
    $bbcode = format_bbcode(htmlspecialchars($_POST['data']));

    // Show as code:
    echo "<p>The BBCode source:</p>\n";
    echo '<p>', htmlspecialchars($bbcode), "</p>\n";

    // Display it:
    echo "<p>The BBCode displayed:</p>\n";
    echo $bbcode;
}
?>
<form action="<?= $_SERVER['PHP_SELF'] ?>" method="post" name="f1">
<p>Enter some data:</p>
<p><textarea name="data" cols="80"
    rows="10"><?= @$_POST['data'] ?></textarea></p>
<p><input type="submit" /></p>
</form>