如何强制使用文件上载字段

Question

Hello can anyone plz fix this problem.

my input field is below code and I am doing validation on form submit i.eis:

<input name="file[]" type="file" multiple="multiple">

<form name="bdmrequest" enctype="multipart/form-data" method="post"  action="<?php echo $_SERVER["PHP_SELF"];?>" onsubmit="return(validate());">

i have included validate.js in header and i am able to do validation of other fields except file upload. validation code i am using:

if(document.bdmrequest.file.value== "")
  {
   alert("Attachment Required");
   document.bdmrequest.file.focus();
    return false;
  } 

js doesn't support me to use (document.bdmrequest.file[].value== "") please suggest me the alternatives. the name of my input type has to be file[] only.

Answer 1

If you need pure Javascript: Demo Fiddle

function validate(){
    var inp = document.getElementById('upload');
    if(inp.files.length === 0){
        alert("Attachment Required");
        inp.focus();

        return false;
    }
}

jQuery:

function validate(){

    if($('#upload')[0].files.length === 0){
        alert("Attachment Required");
        $('#upload').focus();

        return false;
    }
}

Answer 2

不需要JavaScript验证，您可以在输入类型中使用“required”属性....

 <input type="file" required="required">

Answer 3

You can check if the value is empty.

<input name="file[]" type="file" multiple="multiple" id="uploadField">

And then in js:

if($("#uploadField").val() != ""){
      //your success code here
}