/**
* 以字符串形式打印变量
* 本方法实现了 var_dump 和 print_r 类似的功能，但在处理复杂对象如 Yii 控制器时更强大。
* @param mixed $var 要打印的变量
* @param integer $depth dumper 要进入的变量的最大深度，缺省为 10
* @param boolean $highlight 结果是否语法高亮
* @return string 变量的字符串表现形式
*/
public static function dumpAsString($var, $depth = 10, $highlight = false)
{
self::$_output = '';
self::$_objects = [];
self::$_depth = $depth;
self::dumpInternal($var, 0);
if ($highlight) {
$result = highlight_string("<?php\n" . self::$_output, true);
self::$_output = preg_replace('/<\\?php<br \\/>/', '', $result, 1);
}
return self::$_output;
}
/**
* Exports a variable as a string representation.
*
* The string is a valid PHP expression that can be evaluated by PHP parser
* and the evaluation result will give back the variable value.
*
* This method is similar to `var_export()`. The main difference is that
* it generates more compact string representation using short array syntax.
*
* It also handles objects by using the PHP functions serialize() and unserialize().
*
* PHP 5.4 or above is required to parse the exported value.
*
* @param mixed $var the variable to be exported.
* @return string a string representation of the variable
*/
public static function export($var)
{
self::$_output = '';
self::exportInternal($var, 0);
return self::$_output;
}
/**
* @param mixed $var variable to be exported
* @param integer $level depth level
*/
private static function exportInternal($var, $level)
{
switch (gettype($var)) {
case 'NULL':
self::$_output .= 'null';
break;
case 'array':
if (empty($var)) {
self::$_output .= '[]';
} else {
$keys = array_keys($var);
$outputKeys = $keys !== range(0, count($var) - 1);
$spaces = str_repeat(' ', $level * 4);
self::$_output .= '[';
foreach ($keys as $key) {
self::$_output .= "\n" . $spaces . ' ';
if ($outputKeys) {
self::exportInternal($key, 0);
self::$_output .= ' => ';
}
self::exportInternal($var[$key], $level + 1);
self::$_output .= ',';
}
self::$_output .= "\n" . $spaces . ']';
}
break;
case 'object':
if ($var instanceof \Closure) {
self::$_output .= self::exportClosure($var);
} else {
try {
$output = 'unserialize(' . var_export(serialize($var), true) . ')';
} catch (\Exception $e) {
// serialize may fail, for example: if object contains a `\Closure` instance
// so we use a fallback
if ($var instanceof Arrayable) {
self::exportInternal($var->toArray(), $level);
return;
} elseif ($var instanceof \IteratorAggregate) {
$varAsArray = [];
foreach ($var as $key => $value) {
$varAsArray[$key] = $value;
}
self::exportInternal($varAsArray, $level);
return;
} elseif (method_exists($var, '__toString')) {
$output = var_export($var->__toString(), true);
} else {
$outputBackup = self::$_output;
$output = var_export(self::dumpAsString($var), true);
self::$_output = $outputBackup;
}
}
self::$_output .= $output;
}
break;
default:
self::$_output .= var_export($var, true);
}
}
