[PHP] Several situations of JSON value transfer and PHP reception

Using Chrome's backend network, we analyzed several situations when posting json data to PHP through JQuery's $.ajax():

• Cannot get json data through $_POST and $_REQUEST in PHP, that is

  <span>$json</span> = <span>$_POST</span>['json'];  <span>//</span><span> empty($json) 为1</span>

Note: PHP only recognizes application/x-www.form-urlencoded standard data types by default. Therefore, content such as text/xml or soap or application/octet-stream cannot be parsed. If you use $ _POST array will fail to receive.

Scenario A:

In js there is no added attribute contentType: "application/json; charset=utf-8",

<span>var</span> submit_sync = <span>function</span><span>() {
    $.ajax({
        type: </span>"post"<span>,
        url: </span>'add-post-json.php'<span>,
        async: </span><span>false</span>, <span>//</span><span> 使用同步方式</span>
        <span>//</span><span> 1 需要使用JSON.stringify 否则格式为 a=2&b=3&now=14...</span>
        <span>//</span><span> 2 需要强制类型转换，否则格式为 {"a":"2","b":"3"}</span>
<span>        data: JSON.stringify({                  
            a: parseInt($(</span>'input[name="a"]'<span>).val()),
            b: parseInt($(</span>'input[name="b"]'<span>).val()),
            now: </span><span>new</span> Date().getTime() <span>//</span><span> 注意不要在此行增加逗号</span>
<span>        }),
        
        dataType: </span>"json"<span>,
        success: </span><span>function</span><span>(data) {
            $(</span>'#result'<span>).text(data.result);
        } </span><span>//</span><span> 注意不要在此行增加逗号</span>
<span>    });
}</span>

• After using $GLOBALS['HTTP_RAW_POST_DATA'] cannot get the data, that is

<span>$json</span> = <span>$GLOBALS</span>['HTTP_RAW_POST_DATA'];  <span>//</span><span> empty($json) 为 1</span>

• Use file_get_contents("php://input"); You can get the data, that is

<span>$json</span> = <span>file_get_contents</span>("php://input");   <span>//</span><span> empty($json) 为 0</span>

Situation B:

Add attribute contentType to js: "application/json; charset=utf-8",

<span>var</span> submit_sync = <span>function</span><span>() {
        $.ajax({
            type: </span>"post"<span>,
            url: </span>'add-post-json.php'<span>,
            async: </span><span>false</span>, <span>//</span><span> 使用同步方式</span>
            <span>//</span><span> 1 需要使用JSON.stringify 否则格式为 a=2&b=3&now=14...</span>
            <span>//</span><span> 2 需要强制类型转换，否则格式为 {"a":"2","b":"3"}</span>
<span>            data: JSON.stringify({                  
                a: parseInt($(</span>'input[name="a"]'<span>).val()),
                b: parseInt($(</span>'input[name="b"]'<span>).val()),
                now: </span><span>new</span> Date().getTime() <span>//</span><span> 注意不要在此行增加逗号</span>
<span>            }),
            <span>contentType: </span></span>"application/json; charset=utf-8"<span><span>,</span></span>

<em><span>            dataType: </span>"json"<span>,
            success: </span><span>function</span><span>(data) {
                $(</span>'#result'<span>).text(data.result);
            } </span><span>//</span><span> 注意不要在此行增加逗号</span>
<span>        });
    }</span></em>

• After using $GLOBALS['HTTP_RAW_POST_DATA'] you can get the data, that is

<span>$json</span> = <span>$GLOBALS</span>['HTTP_RAW_POST_DATA'];  <span>//</span><span> empty($json) 为 0</span>

• Use file_get_contents("php://input"); You can get the data, that is

<span>$json</span> = <span>file_get_contents</span>("php://input");   <span>//</span><span> empty($json) 为 0</span>

Note: php://input allows reading the raw data of POST. It puts less pressure on memory than $HTTP_RAW_POST_DATA and does not require any special php.ini settings. php://input cannot be used with enctype="multipart/form-data".

Case C:

Would you like to join the following

<span>header</span>('Content-Type:application/json;charset=utf-8');

It has no impact on the results of case A and case B.

Starting from version 5.2, PHP natively provides json_encode() and json_decode() functions, the former is used for encoding, and the latter is used for decoding. The following blog is very detailed, mark!

Using JSON in PHP language: http://www.ruanyifeng.com/blog/2011/01/json_in_php.html

The above has introduced several situations of [PHP] JSON value transfer and PHP reception, including relevant content. I hope it will be helpful to friends who are interested in PHP tutorials.