使用php比较文本内容的差异

时间:2014-07-22 14:48来源: 作者: 点击: 次

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这个类可以查找和查看文本字符串之间的差异。它有两个文本字符串和使用的差异算法来找出它们之间的差异，并返回一个列表的变化，来修补原来的字符串成为最后的字符串。

这个类可以查找和查看文本字符串之间的差异。

它有两个文本字符串和使用的差异算法来找出它们之间的差异，并返回一个列表的变化，来修补原来的字符串成为最后的字符串。

<?php
/*
 *from:http://www.codepearl.com
 */
	require('diff.php');
 
 $before = IsSet($_POST['before']) ? $_POST['before'] : 'Some text before';
 $after = IsSet($_POST['after']) ? $_POST['after'] : 'This is the text after';
 $mode = (IsSet($_POST['mode']) ? $_POST['mode'] : 'w');
?>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html lang="en">
<head>
<title>Test the Diff Object</title>
<meta http-equiv="content-type" content="text/html; charset=iso-8859-1">
<style type="text/css">
* { font-family: sans-serif,arial,helvetica }
</style>
<body>
<form method="POST" action="?">
<div><label for="before">Before</label><br>
<textarea id="before" cols="80" rows="10" name="before"><?php echo HtmlSpecialChars($before); ?></textarea></div>
<div><label for="after">After</label><br>
<textarea id="after" cols="80" rows="10" name="after"><?php echo HtmlSpecialChars($after); ?></textarea></div>
<div><input type="submit" name="compare" value="Compare"> by <select name="mode">
<option value="c"<?php if($mode === 'c') echo ' selected'; ?>>Character</option>
<option value="w"<?php if($mode === 'w') echo ' selected'; ?>>Word</option>
<option value="l"<?php if($mode === 'l') echo ' selected'; ?>>Line</option>
</select></div>
<?php
	if(IsSet($_POST['compare']))
	{
		$diff = new diff_class;
		$difference = new stdClass;
		$difference->mode = $mode;
		if($diff->FormatDiffAsHtml($before, $after, $difference))
			echo '<div>Difference<br><div style="border-style: solid; border-width: 1px">', $difference->html, '</div></div>';
		else
			echo '<div>Error: ', HtmlSpecialChars($diff->error), '</div>';
	}
?>
</form>
</body>
</html>

2. [代码]操作类跳至 [1] [2] [全屏预览]

<?php
/*
 *from：http://www.codepearl.com
 */

/*
{metadocument}<?xml version="1.0" encoding="ISO-8859-1" ?>
<class>

	<package>http://www.codepearl.com</package>

	<version>@(#) $Id: diff.php,v 1.4 2013/11/06 21:19:07 mlemos Exp $</version>
	<copyright>Copyright ?(C) http://www.codepearl.com</copyright>
	<title>OAuth client</title>
	<author>Manuel Lemos</author>
	<authoraddress>http://www.codepearl.com</authoraddress>

	<documentation>
		<idiom>en</idiom>
		<purpose>.</purpose>
		<usage>.</usage>
	</documentation>

{/metadocument}
*/

class diff_class
{
	var $error = '';
	var $insertedStyle = 'font-weight: bold';
	var $deletedStyle = 'text-decoration: line-through';

	Function SplitString($string, $separators, $end, &$positions)
	{
		$l = strlen($string);
		$split = array();
		for($p = 0; $p < $l;)
		{
			$e = strcspn($string, $separators.$end, $p);
			$e += strspn($string, $separators, $p + $e);
			$split[] = substr($string, $p, $e);
			$positions[] = $p;
			$p += $e;
			if(strlen($end)
			&& ($e = strspn($string, $end, $p)))
			{
				$split[] = substr($string, $p, $e);
				$positions[] = $p;
				$p += $e;
			}
		}
		$positions[] = $p;
		return $split;
	}

/*
{metadocument}
	<function>
		<name>Diff</name>
		<type>BOOLEAN</type>
		<documentation>
			<purpose>.</purpose>
			<usage>.</usage>
		</documentation>
		<argument>
			<name>before</name>
			<type>STRING</type>
			<documentation>
				<purpose>.</purpose>
			</documentation>
		</argument>
		<argument>
			<name>after</name>
			<type>STRING</type>
			<documentation>
				<purpose>.</purpose>
			</documentation>
		</argument>
		<argument>
			<name>difference</name>
			<type>HASH</type>
			<out />
			<documentation>
				<purpose>.</purpose>
			</documentation>
		</argument>
		<do>
{/metadocument}
*/
	Function Diff($before, $after, &$difference)
	{
		$mode = (IsSet($difference->mode) ? $difference->mode : 'c');
		switch($mode)
		{
			case 'c':
				$lb = strlen($before);
				$la = strlen($after);
				break;

			case 'w':
				$before = $this->SplitString($before, " \t", "\r\n", $posb);
				$lb = count($before);
				$after = $this->SplitString($after, " \t", "\r\n", $posa);
				$la = count($after);
				break;

			case 'l':
				$before = $this->SplitString($before, "\r\n", '', $posb);
				$lb = count($before);
				$after = $this->SplitString($after, "\r\n", '', $posa);
				$la = count($after);
				break;

			default:
				$this->error = $mode.' is not a supported more for getting the text differences';
				return false;
		}
		$diff = array();
		for($b = $a = 0; $b < $lb && $a < $la;)
		{
			for($pb = $b; $a < $la && $pb < $lb && $after[$a] === $before[$pb]; ++$a, ++$pb);
			if($pb !== $b)
			{
				$diff[] = array(
					'change'=>'=',
					'position'=>($mode === 'c'  ? $b : $posb[$b]),
					'length'=>($mode === 'c' ? $pb - $b : $posb[$pb] - $posb[$b])
				);
				$b = $pb;
			}
			if($b === $lb)
				break;
			for($pb = $b; $pb < $lb; ++$pb)
			{
				for($pa = $a ; $pa < $la && $after[$pa] !== $before[$pb]; ++$pa);
				if($pa !== $la)
					break;
			}
			if($pb !== $b)
			{
				$diff[] = array(
					'change'=>'-',
					'position'=>($mode === 'c'  ? $b : $posb[$b]),
					'length'=>($mode === 'c' ? $pb - $b : $posb[$pb] - $posb[$b])
				);
				$b = $pb;
			}
			if($pa !== $a)
			{
				$diff[] = array(
					'change'=>'+',
					'position'=>($mode === 'c'  ? $a : $posa[$a]),
					'length'=>($mode === 'c' ? $pa - $a : $posa[$pa] - $posa[$a])
				);
				$a = $pa;
			}
		}
		if($a < $la)
		{
			$diff[] = array(
				'change'=>'+',
				'position'=>($mode === 'c'  ? $a : $posa[$a]),
				'length'=>($mode === 'c' ? $la - $a : $posa[$la] - $posa[$a])
			);
		}
		$difference->difference = $diff;
		return true;
	}
/*
{metadocument}
		</do>
	</function>
{/metadocument}
*/

	Function FormatDiffAsHtml($before, $after, &$difference)
	{
		if(!$this->diff($before, $after, $difference))
		{
			return false;
		}
		$html = '';
		$insertedStyle = (strlen($this->insertedStyle) ? ' style="'.HtmlSpecialChars($this->insertedStyle).'"' : '');
		$deletedStyle = (strlen($this->deletedStyle) ? ' style="'.HtmlSpecialChars($this->deletedStyle).'"' : '');
		$td = count($difference->difference);
		for($d = 0; $d < $td; ++$d)
		{
			$diff = $difference->difference[$d];
			switch($diff['change'])
			{
				case '=':
					$html .= nl2br(HtmlSpecialChars(substr($before, $diff['position'], $diff['length'])));
					break;
				case '-':
					$html .= '<del'.$deletedStyle.'>'.nl2br(HtmlSpecialChars(substr($before, $diff['position'], $diff['length']))).'</del>';
					break;
				case '+':
					$html .= '<ins'.$insertedStyle.'>'.nl2br(HtmlSpecialChars(substr($after, $diff['position'], $diff['length']))).'</ins>';
					break;
				default:
					$this->error = $diff['change'].' is not an expected difference change type';
					return false;
			}
		}
		$difference->html = $html;
		return true;
	}
};

/*

{metadocument}
</class>
{/metadocument}

*/

?>