receive serialize data in php sent via ajax and loop through it

Question

I am sending a form data via ajax call to a php script. I am serializing the data in ajax and on the php script I want to loop through that data to extract the values. This is my ajax call

$("#submitAttendance").click(function(){
            var data = $('form#attendanceForm').serialize();
            $.ajax({
                url: 'save-attendance.php',
                method: 'post',
                data: {formData: data},
                success: function(data){
                    console.log(data);
                    alert(data);
                }
        });
        });

and in the attendance.php I am doing

print_r(($_POST['formData']));//prints the entire serialize data

when I do this

parse_str($_POST['formData'], $searcharray);

print_r(($searcharray));//prints only last user and all radio buttons

I want to extract values so I can save it in db. This is my form

<form action="" id="attendanceForm">
            <?php
            if(mysqli_num_rows($result)>0){
                while($row = $result->fetch_assoc()){ ?>
                    <tr>
                        <input type="hidden" value="<?php echo($row['id']);?>">
                        <td><input type="text" name="name" value="<?php echo $row['fullname'];?>" readonly></td>
                        <td><input type="text" name="email" value="<?php echo $row['email'];?>" readonly</td>
                        <td><input type="text" name="class" value="<?php echo $row['class'];?>" readonly</td>
                        <td><input type="radio" value="present" name="<?php echo($row['id']); ?>" checked></td>
                        <td><input type="radio" value="absent" name="<?php echo($row['id']); ?>"></td>
                    </tr>


                <?php }
            }
            ?>
                <input id="submitAttendance" type="button" class="btn btn-success" value="Submit Attendance" name="submitAttendance">
            </form>

Answer 1

You need to rename your items to be able to post arrays (that is call them "whatever" + "[]" and loop over them in PHP), eg:

HTML:

<form action="" id="attendanceForm">
            <?php
            if(mysqli_num_rows($result)>0){
                while($row = $result->fetch_assoc()){ ?>
                    <tr>
                        <input type="hidden" value="<?php echo($row['id']);?>">
                        <td><input type="text" name="name[]" value="<?php echo $row['fullname'];?>" readonly></td>
                        <td><input type="text" name="email[]" value="<?php echo $row['email'];?>" readonly</td>
                        <td><input type="text" name="class[]" value="<?php echo $row['class'];?>" readonly</td>
                        <td><input type="radio" value="present" name="<?php echo($row['id']); ?>" checked></td>
                        <td><input type="radio" value="absent" name="<?php echo($row['id']); ?>"></td>
                    </tr>


                <?php }
            }
            ?>
                <input id="submitAttendance" type="button" class="btn btn-success" value="Submit Attendance" name="submitAttendance">
            </form>

Later in PHP:

foreach ($_POST["formData"]["name"] as $name)
    echo "Wow, $name is a really pretty name!";

Additionally, I am not sure what present and absent are meant to do and why they should have the same name (an id). You are already posting the id as an hidden field, why should it be done twice? One overrides the other one (as the names have to be unique).

Answer 2

In addition to @Jan answer I did following to get the complete data and loop through it

parse the incoming data

parse_str($_POST['formData'], $searcharray);

then loop through the array

for ($i = 0 ; $i <= sizeof($searcharray) ; $i++){
            $name = $searcharray['name'][$i];
            $email=   $searcharray['email'][$i];
            $class =  $searcharray['class'][$i];
            $present=  ($searcharray['present'][$i]);
    }

and my form code is

<form action="" id="attendanceForm">
            <?php
            if(mysqli_num_rows($result)>0){
                $i=0;
                while($row = $result->fetch_assoc()){

                    ?>
                    <tr>
                        <input type="hidden" value="<?php echo($row['id']);?>">
                        <td><input type="text" name="name[]" value="<?php echo $row['fullname'];?>" readonly></td>
                        <td><input type="text" name="email[]" value="<?php echo $row['email'];?>" readonly</td>
                        <td><input type="text" name="class[]" value="<?php echo $row['class'];?>" readonly</td>
                        <td><input type="radio" value="present" name="present[<?php echo $i; ?>]" checked></td>
                        <td><input type="radio" value="absent" name="present[<?php echo $i; ?>]"></td>
                    </tr>


                <?php $i++;
                }
            }
            ?>
                <input id="submitAttendance" type="button" class="btn btn-success" value="Submit Attendance" name="submitAttendance">
            </form>