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YII CJson类

时间:2014-07-27 10:17:32      阅读:309      评论:0      收藏:0      [点我收藏+]

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CJson文档:

http://www.yiiframework.com/doc/api/1.1/CJSON

CJson::encode可以编码任何类型的数据:源码如下;

public static function encode($var)
{
    switch (gettype($var)) {
        case ‘boolean‘:
            return $var ? ‘true‘ : ‘false‘;

        case ‘NULL‘:
            return ‘null‘;

        case ‘integer‘:
            return (int) $var;

        case ‘double‘:
        case ‘float‘:
            return str_replace(‘,‘,‘.‘,(float)$var); // locale-independent representation

        case ‘string‘:
            if (($enc=strtoupper(Yii::app()->charset))!==‘UTF-8‘)
                $var=iconv($enc, ‘UTF-8‘, $var);

            if(function_exists(‘json_encode‘))
                return json_encode($var);

            // STRINGS ARE EXPECTED TO BE IN ASCII OR UTF-8 FORMAT
            $ascii = ‘‘;
            $strlen_var = strlen($var);

           /*
            * Iterate over every character in the string,
            * escaping with a slash or encoding to UTF-8 where necessary
            */
            for ($c = 0; $c < $strlen_var; ++$c) {

                $ord_var_c = ord($var{$c});

                switch (true) {
                    case $ord_var_c == 0x08:
                        $ascii .= ‘\b‘;
                        break;
                    case $ord_var_c == 0x09:
                        $ascii .= ‘\t‘;
                        break;
                    case $ord_var_c == 0x0A:
                        $ascii .= ‘\n‘;
                        break;
                    case $ord_var_c == 0x0C:
                        $ascii .= ‘\f‘;
                        break;
                    case $ord_var_c == 0x0D:
                        $ascii .= ‘\r‘;
                        break;

                    case $ord_var_c == 0x22:
                    case $ord_var_c == 0x2F:
                    case $ord_var_c == 0x5C:
                        // double quote, slash, slosh
                        $ascii .= ‘\\‘.$var{$c};
                        break;

                    case (($ord_var_c >= 0x20) && ($ord_var_c <= 0x7F)):
                        // characters U-00000000 - U-0000007F (same as ASCII)
                        $ascii .= $var{$c};
                        break;

                    case (($ord_var_c & 0xE0) == 0xC0):
                        // characters U-00000080 - U-000007FF, mask 110XXXXX
                        // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                        $char = pack(‘C*‘, $ord_var_c, ord($var{$c+1}));
                        $c+=1;
                        $utf16 =  self::utf8ToUTF16BE($char);
                        $ascii .= sprintf(‘\u%04s‘, bin2hex($utf16));
                        break;

                    case (($ord_var_c & 0xF0) == 0xE0):
                        // characters U-00000800 - U-0000FFFF, mask 1110XXXX
                        // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                        $char = pack(‘C*‘, $ord_var_c,
                                     ord($var{$c+1}),
                                     ord($var{$c+2}));
                        $c+=2;
                        $utf16 = self::utf8ToUTF16BE($char);
                        $ascii .= sprintf(‘\u%04s‘, bin2hex($utf16));
                        break;

                    case (($ord_var_c & 0xF8) == 0xF0):
                        // characters U-00010000 - U-001FFFFF, mask 11110XXX
                        // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                        $char = pack(‘C*‘, $ord_var_c,
                                     ord($var{$c+1}),
                                     ord($var{$c+2}),
                                     ord($var{$c+3}));
                        $c+=3;
                        $utf16 = self::utf8ToUTF16BE($char);
                        $ascii .= sprintf(‘\u%04s‘, bin2hex($utf16));
                        break;

                    case (($ord_var_c & 0xFC) == 0xF8):
                        // characters U-00200000 - U-03FFFFFF, mask 111110XX
                        // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                        $char = pack(‘C*‘, $ord_var_c,
                                     ord($var{$c+1}),
                                     ord($var{$c+2}),
                                     ord($var{$c+3}),
                                     ord($var{$c+4}));
                        $c+=4;
                        $utf16 = self::utf8ToUTF16BE($char);
                        $ascii .= sprintf(‘\u%04s‘, bin2hex($utf16));
                        break;

                    case (($ord_var_c & 0xFE) == 0xFC):
                        // characters U-04000000 - U-7FFFFFFF, mask 1111110X
                        // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                        $char = pack(‘C*‘, $ord_var_c,
                                     ord($var{$c+1}),
                                     ord($var{$c+2}),
                                     ord($var{$c+3}),
                                     ord($var{$c+4}),
                                     ord($var{$c+5}));
                        $c+=5;
                        $utf16 = self::utf8ToUTF16BE($char);
                        $ascii .= sprintf(‘\u%04s‘, bin2hex($utf16));
                        break;
                }
            }

            return ‘"‘.$ascii.‘"‘;

        case ‘array‘:
           /*
            * As per JSON spec if any array key is not an integer
            * we must treat the the whole array as an object. We
            * also try to catch a sparsely populated associative
            * array with numeric keys here because some JS engines
            * will create an array with empty indexes up to
            * max_index which can cause memory issues and because
            * the keys, which may be relevant, will be remapped
            * otherwise.
            *
            * As per the ECMA and JSON specification an object may
            * have any string as a property. Unfortunately due to
            * a hole in the ECMA specification if the key is a
            * ECMA reserved word or starts with a digit the
            * parameter is only accessible using ECMAScript‘s
            * bracket notation.
            */

            // treat as a JSON object
            if (is_array($var) && count($var) && (array_keys($var) !== range(0, sizeof($var) - 1))) {
                return ‘{‘ .
                       join(‘,‘, array_map(array(‘CJSON‘, ‘nameValue‘),
                                           array_keys($var),
                                           array_values($var)))
                       . ‘}‘;
            }

            // treat it like a regular array
            return ‘[‘ . join(‘,‘, array_map(array(‘CJSON‘, ‘encode‘), $var)) . ‘]‘;

        case ‘object‘:
            if ($var instanceof Traversable)
            {
                $vars = array();
                foreach ($var as $k=>$v)
                    $vars[$k] = $v;
            }
            else
                $vars = get_object_vars($var);
            return ‘{‘ .
                   join(‘,‘, array_map(array(‘CJSON‘, ‘nameValue‘),
                                       array_keys($vars),
                                       array_values($vars)))
                   . ‘}‘;

        default:
            return ‘‘;
    }
}

 

 $item = Item::model()->findByPk($_GET[‘id‘]); 
CJSON::encode($item)。
如果换成json_encode则错误,因为$item类型为CActiveRecord.
我们可以
$item->attributes;得到Returns all column attribute values.
然后才可以使用json_encode。

转一篇文章:

近日在了解YII中的JSON操作方法,发现内置了好几种进行JSON对象和字符串,包括JS的JSON互通的方法,下面是三种方式的JSON解析:上代码

 

[php] view plaincopy
 
  1. CJSON::encode( $json );  
  2. json_encode( $json );  
  3. CJavaScript::jsonEncode( $json );  
我们还是来看个例子吧!先上代码吧:

 

 

[php] view plaincopy
 
  1. $json = array (  
  2.         ‘item1‘ => array (  
  3.                 ‘item11‘ => array (  
  4.                         ‘n‘ => ‘chenling‘,  
  5.                         ‘m‘ => ‘llll‘   
  6.                 ),  
  7.                 ‘sex‘ => ‘男‘,  
  8.                 ‘age‘ => 25,  
  9.                 ‘admin‘=>true   
  10.         ),  
  11.         ‘item2‘ => array (  
  12.                 ‘item21‘ => ‘ling‘,  
  13.                 ‘sex‘ => ‘女‘,  
  14.                 ‘age‘ => ‘24‘,  
  15.                 ‘admin‘=>false   
  16.         )   
  17. );  

这上面是个三个层级的数组,数组的值包括了字符串、boolean、和数字,我们通过上面的三种方式来输出看看结果是什么:

 

 

[php] view plaincopy
 
  1. $jsonObj = CJSON::encode( $json );  
  2. $jsono = json_encode( $json );  
  3. $jsonjs = CJavaScript::jsonEncode( $json );  
  4. echo $jsonObj.‘<br />‘;  
  5. echo $jsonjs.‘<br />‘;  
  6. echo $jsono.‘<br />‘;  
结果:

 

bubuko.com,布布扣

看来三种方式都可以,解析出来的也是一样的。如果要访问数组的值的话,用下面的 代码就行了。


 
  1. echo $json[‘item1‘][‘sex‘].‘<br />‘;  

 

现在来看看转换成JSON对象的方法:

 


 
  1. $jsonstr=‘{"item1":{"item11":{"n":"chenling","m":"llll"},"sex":"男","age":"25"},"item2":{"item21":"ling","sex":"女","age":"24"}}‘;  
  2. echo $jsonstr.‘<br />‘;  

 
  1. //$j = CJSON::decode($jsonstr);  
  2. //$j = CJavaScript::jsonDecode($jsonstr);  
  3. <span style="color:#ff0000;"><strong>$j = json_decode($jsonstr,true);//当字符串为{"1":1,"2":1} 这种模式时,json_decode默认解析出来的结果是一个对象,此时可以设置它的第二个参数为true强制让它返回数组</strong></span>  

 

上面两个方法转换都是没有问题的,关键是上面红色标注的就有问题了,如果我没有加后面的参数true的话,结果就是下面的报错信息,原因就是因为

当字符串为{"1":1,"2":1} 这种模式时,json_decode默认解析出来的结果是一个对象,此时可以设置它的第二个参数为true强制让它返回数组。

bubuko.com,布布扣

如果是下面的这个代码,则转换就没有问题

  1. $jsonstr = ‘[1,2,3]‘;  
  2. $j = json_decode($jsonstr);//如果不加第二个参数的话,当字符串为[1,2,3] 这种模式时,json_decode默认解析出来的结果是一个数组  
  3. echo $j[2].‘<br />‘;  

 

所以这个是要注意的,同时我们可能遇到下面的这种情况的JSON字符串,这个也是要注意的!尤其是要注意转换完成后的数组访问方式
 
  1. $jsonstr=‘{"item1":[{"name":[{"chen":"chenling","ling":"chenli"}],"sex":"男","age":"25"},{"name":"sun","sex":"女","age":"24"}]}‘;  
  2. $j = CJSON::decode($jsonstr);  
  3. echo $j[‘item1‘][0][‘name‘][0][‘chen‘].‘<br />‘;  
  4. <strong><span style="color:#ff0000;">$j = json_decode($jsonstr,true);</span></strong>  
  5. echo $j[‘item1‘][0][‘name‘][0][‘chen‘].‘<br />‘;  
  6. $j = CJavaScript::jsonDecode($jsonstr);  
  7. echo $j[‘item1‘][0][‘name‘][0][‘chen‘].‘<br />‘;  

 

 

这种情况也得注意,都是数组的情况下,只能通过索引进行访问,而不能通过key来访问。
 
 
  1. $jsonstr=‘[["item1","item11"],["n","chenling"],["m","llll"]]‘;  
  2. $j = CJSON::decode($jsonstr);  
  3. echo $j[1][1].‘<br />‘;  
  4. $j = json_decode($jsonstr);  
  5. echo $j[0][0].‘<br />‘;  
  6. $j = CJavaScript::jsonDecode($jsonstr);  
  7. echo $j[0][0].‘<br />‘;  

也就是说在这三种的情况下:

CJSON和CJavaScript的方式是可以通用的,而json_的方式是需要第二个参数来决定的。所以为了兼容,我们还是尽量使用前两个进行JSON的转换操作;

 

转自:  http://blog.csdn.net/qq415734794/article/details/7662449

 

YII CJson类

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原文地址:http://www.cnblogs.com/youxin/p/3870581.html

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