通过使用自动换行功能。它将文本分成多行,以使最大宽度为您指定的宽度,并在单词边界处断开。拆分后,您只需走第一行:
substr($string, 0, strpos(wordwrap($string, $your_desired_width), "\n"));
文本本身短于所需宽度时,oneliner无法处理的一件事。要处理这种情况,应该执行以下操作:
if (strlen($string) > $your_desired_width)
{
$string = wordwrap($string, $your_desired_width);
$string = substr($string, 0, strpos($string, "\n"));
}
如果文本在实际剪切点之前包含换行符,则上述解决方案存在过早剪切文本的问题。这里是解决此问题的版本:
function tokenTruncate($string, $your_desired_width) {
$parts = preg_split('/([\s\n\r]+)/', $string, null, PREG_SPLIT_DELIM_CAPTURE);
$parts_count = count($parts);
$length = 0;
$last_part = 0;
for (; $last_part < $parts_count; ++$last_part) {
$length += strlen($parts[$last_part]);
if ($length > $your_desired_width) { break; }
}
return implode(array_slice($parts, 0, $last_part));
}
另外,这是用于测试实现的PHPUnit测试类:
class TokenTruncateTest extends PHPUnit_Framework_TestCase {
public function testBasic() {
$this->assertEquals("1 3 5 7 9 ",
tokenTruncate("1 3 5 7 9 11 14", 10));
}
public function testemptyString() {
$this->assertEquals("",
tokenTruncate("", 10));
}
public function testShortString() {
$this->assertEquals("1 3",
tokenTruncate("1 3", 10));
}
public function testStringTooLong() {
$this->assertEquals("",
tokenTruncate("toooooooooooolooooong", 10));
}
public function testContainingNewline() {
$this->assertEquals("1 3\n5 7 9 ",
tokenTruncate("1 3\n5 7 9 11 14", 10));
}
}
不处理特殊的UTF8字符,例如“à”。在REGEX的末尾添加’u’来处理它:
$parts = preg_split('/([\s\n\r]+)/u', $string, null, PREG_SPLIT_DELIM_CAPTURE);