dtmm0148603 2013-12-14 07:59
浏览 152
已采纳

Ajax:如何使用FormData和jQuery发送'empty'文件并在$ _FILES中获取它

I have html form and want send file 'myfile' with Ajax and jQuery:

<form method="post" enctype="multipart/form-data">
    <input type="file" name="myfile" id="myfile">
</form>

My javascript code:

function getFile(fieldName){
    var itemValue = $('input[name="' + fieldName + '"]')[0].files[0];
    return itemValue;
}

function sendFile(){
    var formaData = new FormData();
    var itemName = 'myfile';
    var itemValue = getFile(itemName);
    formaData.append(itemName, itemValue);
    $.ajax({
        type: 'POST',
        data: formaData,
        processData: false,
        contentType: false,
    });
}

All works fine when file is choosen. I have in the server $_FILES global array and data in it which got via Ajax:

["myfile"]=>
    array(5) {
        ["name"]=>
        string(13) "file_name.jpg"
        ["type"]=>
        string(10) "image/jpeg"
        ["tmp_name"]=>
        string(14) "/tmp/phpefJlk3"
        ["error"]=>
        int(0)
        ["size"]=>
        int(344100)
    }

The problem when file is not choosen! When I don't choose any file and send Ajax request then I have empty $_FILES, but I have $_POST with field 'myfile' equals 'undefined'. But I need 'myfile' field in $_FILES even it is empty. I want something like:

["myfile"]=>
    array(5) {
        ["name"]=>
        string(0) ""
        ["type"]=>
        string(0) ""
        ["tmp_name"]=>
        string(0) ""
        ["error"]=>
        int(4)
        ["size"]=>
        int(0)
    }

Above is what I have in $_FILES globall array if I send empty form without Ajax. I want the same if I using Ajax. Is it posssible?

  • 写回答

2条回答 默认 最新

  • dongzouqie4220 2013-12-14 08:09
    关注

    Handling files with AJAX is not that simple. It comes up with a lot of problems due to different clients, hugh files and all that stuff. (As you can see in your "simple"-Error here =) In your case, no file is selected so there is no need to send information about "no given file". Dont produce overheads. Maybe you take a look into your controller. If the data is that different (AJAXPOST or POST) so create two PHP-Actions. One AJAX handler and one POST handler. In that case you can handle the different post-datas.

    This information will help you: How can I upload files asynchronously?

    You need to use Plugins like Uploadify, or Valums to make that work. Just read a bit more about AJAX and Filepost.

    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论
查看更多回答(1条)

报告相同问题?

悬赏问题

  • ¥15 C#调用python代码(python带有库)
  • ¥15 矩阵加法的规则是两个矩阵中对应位置的数的绝对值进行加和
  • ¥15 活动选择题。最多可以参加几个项目?
  • ¥15 飞机曲面部件如机翼,壁板等具体的孔位模型
  • ¥15 vs2019中数据导出问题
  • ¥20 云服务Linux系统TCP-MSS值修改?
  • ¥20 关于#单片机#的问题:项目:使用模拟iic与ov2640通讯环境:F407问题:读取的ID号总是0xff,自己调了调发现在读从机数据时,SDA线上并未有信号变化(语言-c语言)
  • ¥20 怎么在stm32门禁成品上增加查询记录功能
  • ¥15 Source insight编写代码后使用CCS5.2版本import之后,代码跳到注释行里面
  • ¥50 NT4.0系统 STOP:0X0000007B