how to remember input data in the forms even after refresh page?

what to do in order to make the form remember the previous input or the current input of the user even after he/she refreshed the page ?

should I do ,

            <div class="row">
             <label>Contact Messenger </label>
             <input type="text" name="messenger" id="messenger" size="50" maxlength="50" value="<?php echo $_SESSION['messenger']; ?>"/>
            </div>

or

            <div class="row">
             <label>Contact Messenger </label>
             <input type="text" name="messenger" id="messenger" size="50" maxlength="50" value="<?php echo $_POST['messenger']; ?>"/>
            </div>

or

there's a trick to do it ?..how ?

on the page where your form is submitting do something like this

    session_start();
    $_SESSION['data'] = $_POST['data'];
    $_SESSION['data_another'] = $_POST['data_another'];

and than you can access those session variables any where like this

    session_start(); // this should be at the top of the page before any html load
    <input type="text" name="name" value="<?php echo $_SESSION['data'];?>"/>

refresh your page on success call like this

     $.ajax({
           type: "POST",
           url: "yourfile.php",
           data: 'data='+ data,
           success: function(){
               location.reload();
           }
       });

I had similar issue at one of my project so I wrote some js to handle this using cookies. First I found two simple functions to set and get cookies values:

function setCookie(c_name, value, exdays) {
    var exdate = new Date();
    exdate.setDate(exdate.getDate() + exdays);
    var c_value = escape(value) + ((exdays == null) ? "" : "; expires=" + exdate.toUTCString());
    document.cookie = c_name + "=" + c_value;
}

function getCookie(c_name) {
    var c_value = document.cookie;
    var c_start = c_value.indexOf(" " + c_name + "=");
    if (c_start == -1) {
        c_start = c_value.indexOf(c_name + "=");
    }
    if (c_start == -1) {
        c_value = null;
    } else {
        c_start = c_value.indexOf("=", c_start) + 1;
        var c_end = c_value.indexOf(";", c_start);
        if (c_end == -1) {
            c_end = c_value.length;
        }
        c_value = unescape(c_value.substring(c_start, c_end));
    }
    return c_value;
}

Than I wrote two other functions to set and get input values:

function saveValue(input) {
    var name = input.attr('name');
    var value = input.val();
    setCookie(name,value);
}

function getValue(input) {
    var name = input.attr('name');
    var value = getCookie(name);
    if(value != null && value != "" ) {
        return value;
    }
}

And using jQuery I save user's input value to session cookie

$('input[type=text]').each(function(){
    var value = getValue($(this));
    $(this).val(value);
}).on('blur', function(){
    if($(this).val() != '' ) {
        saveValue($(this));
    }
});

I hope it'll help ;)

That quite depends on where the data in the fields is coming from. If your scenario is that you are presenting a blank form, the user enters some data and then without submitting it, refreshes the page, there is nothing you can do. That's up for the browser to handle.

You might be able to do some very weird JavaScript hacking there, but I would not suggest that.

On the other hand, if your data is coming from a previous page or something like that, that's a different story. But then you need to tell us where the data is coming from, so I can give you a reasonable answer.

If you mean, filling out form fields and clicking refresh, then there is no direct way, as the data isn't submitted. That sort of behavior is up to the browser.

The only thing you could do is post the data via AJAX back to your server as the fields change. Your PHP script receiving the data would set some session variables. When the form loads, you would set their default values to the appropriate session values.

Rarely though is there a need for this kind of behavior. There will be many requests sent back and forth to your server.