javascript - jquery's $.ajax() submits incorrect data to php's post

<code>$('#form1').submit(function(){
        
        $.ajax({ 
            url:'login.php?act=login',
            data:$('#form1').serialize(),
            type:'POST',
            dataType:'text',
            beforeSend:function(){
                }
                if($('#password').val()==''){
                    alert('密碼不能為空');
                    return false;
                }else{
                    var p = $('#password').val();
                    alert(p);
                    $('#password').val(hex_md5(p));
                    alert($('#password').val());
                }
            },
            success:function(msg){
                ......
                };
            }
        });
        return false;
    });</code>

That’s right, my purpose is to perform md5 calculation on the password before submitting it to achieve the function of encrypting and transmitting the password.

But the actual effect is that when my password value is 123, alert($('#password').val()) prints out correctly 202cb962ac59075b964b07152d234b70, but after posting to the background php, it is still 123.

I feel like data:$('#form1').serialize() has already taken the value before beforeSend, so the old value is still passed later.

After testing, if I take out the md5 encryption part and put it before $.ajax() for operation, there will be no problem. It’s just inconvenient to use like this. Is there any way to make serialize() execute after beforeSend?

Supplement:
After using the method provided by @lisfan, the submission is normal

<code>$('#form1').submit(function(){
        
        $.ajax({ 
            url:'login.php?act=login',
            **data:null,**
            type:'POST',
            dataType:'text',
            beforeSend:function(){
                }
                if($('#password').val()==''){
                    alert('密碼不能為空');
                    return false;
                }else{
                    var p = $('#password').val();
                    alert(p);
                    $('#password').val(hex_md5(p));
                    alert($('#password').val());
                    **this.data=$('#form1').serialize();**
                }
            },
            success:function(msg){
                ......
                };
            }
        });
        return false;
    });</code>

But neither $_REQUEST nor $_POST in the background php can receive data. As shown below:

The following is the post data seen by firebug. The above is the data of php printing $_REQUEST, $_POST and php://input respectively. You can see that the original data is seen in file_get_contents("php://input") Data, but why is it not encapsulated in $_POST?

.

Reply content:

<code>$('#form1').submit(function(){
        
        $.ajax({ 
            url:'login.php?act=login',
            data:$('#form1').serialize(),
            type:'POST',
            dataType:'text',
            beforeSend:function(){
                }
                if($('#password').val()==''){
                    alert('密碼不能為空');
                    return false;
                }else{
                    var p = $('#password').val();
                    alert(p);
                    $('#password').val(hex_md5(p));
                    alert($('#password').val());
                }
            },
            success:function(msg){
                ......
                };
            }
        });
        return false;
    });</code>

That’s right, my purpose is to perform md5 calculation on the password before submitting it to achieve the function of encrypting and transmitting the password.

But the actual effect is that when my password value is 123, alert($('#password').val()) prints out correctly 202cb962ac59075b964b07152d234b70, but after posting to the background php, it is still 123.

I feel like data:$('#form1').serialize() has already taken the value before beforeSend, so the old value is still passed later.

After testing, if I take out the md5 encryption part and put it before $.ajax() for operation, there will be no problem. It’s just inconvenient to use like this. Is there any way to make serialize() execute after beforeSend?

Supplement:
After using the method provided by @lisfan, the submission is normal

<code>$('#form1').submit(function(){
        
        $.ajax({ 
            url:'login.php?act=login',
            **data:null,**
            type:'POST',
            dataType:'text',
            beforeSend:function(){
                }
                if($('#password').val()==''){
                    alert('密碼不能為空');
                    return false;
                }else{
                    var p = $('#password').val();
                    alert(p);
                    $('#password').val(hex_md5(p));
                    alert($('#password').val());
                    **this.data=$('#form1').serialize();**
                }
            },
            success:function(msg){
                ......
                };
            }
        });
        return false;
    });</code>

But neither $_REQUEST nor $_POST in the background php can receive data. As shown below:

The following is the post data seen by firebug. The above is the data of php printing $_REQUEST, $_POST and php://input respectively. You can see that the original data is seen in file_get_contents("php://input") Data, but why is it not encapsulated in $_POST?

.

Without modifying the original structure of the question, try modifying it as follows and look at the position of the asterisk *

<code>$('#form1').submit(function(){
        
        $.ajax({ 
            url:'login.php?act=login',
            **data:null,**
            type:'POST',
            dataType:'text',
            beforeSend:function(){
                }
                if($('#password').val()==''){
                    alert('密碼不能為空');
                    return false;
                }else{
                    var p = $('#password').val();
                    alert(p);
                    $('#password').val(hex_md5(p));
                    alert($('#password').val());
                    **this.data=$('#form1').serialize();**
                }
            },
            success:function(msg){
                ......
                };
            }
        });
        return false;
    });</code>

You can process the password before sending the $.AJAX() request. That is to process the content of the beforeSend function first, and then send the request, so that the data of $('#form1').serialize() is correct

This shows that the function $('#form1').serialize() is called before beforeSend.

It is recommended that when you enter the password in the verification function, if the verification is passed, directly encrypt it and assign it to a hidden field in the form

$('#form1').submit(function() {
  if ($('#password').val() == '') {
    alert('密碼不能為空');
    return false;
  }
  var p = $('#password').val();
  alert(p);
  $('#password').val(hex_md5(p));
  alert($('#password').val());


  $.post('login.php?act=login',
    $(this).serialize(),
    function(msg) {
      console.log(msg);
    }
  );
  return false;
});

Take out the judgment and put ajax behind the password encryption.

This is because when executing $.ajax, the js engine will create a literal object. When the object is created, the value of data is stored as the return value of $('#form1').serialize() at that time, also That’s 123.

You can see the following example:
var c=1;
var a={

<code>b:c,
d : function(){
    c=2
}</code>

};

console.log(a.b);// 1
a.d();//c=2
console.log(a.b);// 1
This can be explained The above question is gone.
The possible solution is to move the md5 encryption before creating the literal object.

First of all, since md5 is required, why do we need to assign it to the input of password? Is there no security risk? Secondly, the beforeSend function is called before sending the request, not before the Ajax method. When you call the ajax method, you have already taken out the form data and set it into the parameters of the function. How can the form value modified later be automatically updated? When it comes to ajax data, it is completely whimsical. Just put the password md5 operation before calling the Ajax method

Prepare the encrypted password string before the ajax method