how to increment the previous value by the new value in every refresh

Question

I want to add the existing value with the new value when the webpage refresh. I have two files which are the html and php file. The php file will show a random number between 10 and 100. while the html file perform a get jquery to get the data from the php script. Then after webpage refresh, the existing values must be incremented by the new value. For example,

the first value on the webpage is 24.
after refreshing the page, the new value is 89 from the php script
the value on the webpage must be 113 (24+89).

I am going to show you the code below.

showtotal.php

<?php


$random = rand(10,100);
echo $random;
?>

showtotal.html

<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
</head>
<body>
<script type="text/javascript">
 updateFromServer();
    var intervalID = window.setInterval(updateFromServer, 500);

    function updateFromServer() {
        $.get({
            url: 'showtotal.php',
            dataType: 'text',
            success: totalAttacks
        });
    }

    function totalAttacks(val) {
        $('#result').html('Events Today' + val);
    }
</script>
<h1 id="result"></h1>
</body>
</html>

what my code is show different values in every refresh. How to increment the existing values by the new values? Please help me . thank you

Use [`localStorage`](https://developer.mozilla.org/en-US/docs/Web/API/Window/localStorage). — Sebastian Simon, Oct 31 '17 at 04:44
You need to store that variable either with localstorage or sessionstorage — Neji Soltani, Oct 31 '17 at 04:46
@Xufox, i thought php cant access localstorage . refer to this link https://stackoverflow.com/questions/3855337/php-localstorage — , Oct 31 '17 at 06:17
@Azhar You don’t need to save the value server-side; save it client-side. — Sebastian Simon, Oct 31 '17 at 15:57
If i want the values to be saved if i close the browser and open, I must use cookies??? In other words, i want the value to be permanent — , Nov 02 '17 at 02:54

score 1 · Answer 1 · answered Oct 31 '17 at 04:48

1

You can use cookies, sessionStorage or localStorage to store the lastest value. In the case of the cookie, you can get it through the PHP file, so in your Javascript file you just need to call the PHP file.

answered Oct 31 '17 at 04:48

Frankusky

1,040
9
18

you can access cookies with JS, it's not easy or fun but it can be done. – ArtisticPhoenix Oct 31 '17 at 05:00
I know, the point was that he can move all the logic to the PHP file :) – Frankusky Oct 31 '17 at 05:05
ever parse a cookie with JS by hand, lol, that's some fun times. – ArtisticPhoenix Oct 31 '17 at 05:09
if i want to use permanent storage, meaning if the browser close and open, that value will remain there. which storage do i need to use?? It cant be session storage as it will be reset if the browser close and open – Nov 02 '17 at 02:56
1

@Azhar cookies or localstorage are your options, I will choose localstorage since it is easier to retrieve the data you want – Frankusky Nov 06 '17 at 03:08
is it possible to perform coding localstorage in php – Nov 06 '17 at 06:41
No, localstorage its only accessible from javascript. – Frankusky Nov 06 '17 at 21:36
Damn... I am using php script to show the data. I use ajax get to access the data from the php script. – Nov 07 '17 at 01:49
i think i choose cookies as cookies can be used in php – Nov 07 '17 at 04:37
I apologize for the spamming you @Frankusky – Nov 08 '17 at 07:33

score 0 · Accepted Answer · answered Oct 31 '17 at 05:04

0

You can put your old value in a PHP session and make this calculation in the PHP side, like this:

<?php
session_start();
if(!isset($_SESSION['old_value']))
    $_SESSION['old_value'] = 0;
$random = $_SESSION['old_value'] + rand(10,100);
$_SESSION['old_value'] = $random;
echo $random;
?>

answered Oct 31 '17 at 05:04

Majid Abbasi

1,531
3
12
22

however, when i close the browser and open, the values start from 0. If i want to use permanent storage – Nov 02 '17 at 02:46
1

in this case you are force to save value in the database, session will remove when you close browser. simple save and get $_SESSION['old_value'] from database – Majid Abbasi Nov 02 '17 at 05:35
if i do not want to use database, any other storage that has the ability to be permanent – Nov 02 '17 at 06:04
1

As this data is not an important can save latest status in a file and every-time read and write on that instead of using session – Majid Abbasi Nov 02 '17 at 06:12

score 0 · Answer 3 · answered Oct 31 '17 at 05:05

0

You can store previous value in a hidden field.

function totalAttacks(val) {
    var pre_val = parseInt($('#prev').val());
    var new_val = pre_val+parseInt(val);
    $('#result').html('Events Today' + new_val);
    $('#prev').val(new_val);
}

Also add this to yr html

<input type="hidden" id="prev" value="0">

answered Oct 31 '17 at 05:05

chippy

74
10

I believe this wont work, after refreshing the browser will load your DOM value instead of retrieving the last value – Frankusky Oct 31 '17 at 14:22

how to increment the previous value by the new value in every refresh

3 Answers3