在两个 php 页面之间传递变量的最佳方法

Question

Need to pass a variable from index.php to edit.php .

The variable should be unvisible for visitors, so address bar is not allowed.

First way - using a form on index.php with action attribute - edit.php .

Problem with using a form is a warning about re-submitting which appears each time edit.php is refreshed.

Second way - using ajax call on index.js to change a session variable on php side.

Downside of using ajax is an extra path - firstly go to server side (to change php) - then to client side (success function to get the new value) - and again to server side (go to edit.php using the new variable).

What is the right way?

Is there a simple way like this:

location.href = 'edit.php', set x = 5

And on edit.php to get this:

echo $x (result 5);

Answer 1

You could create a custom cookie in index.js and append to document.cookie and when a request to edit.php is made, it will be available.

index.js

const custom_cookie = "x=5";
document.cookie = custom_cookie;
.....
window.location = 'edit.php';

edit.php

$cookie_name = 'x';
echo $_COOKIE[$cookie_name]

Answer 2

Another way is to use PHP Sessions.

//index.php
$_SESSION['varname'] = $var_value;

//edit.php
$var_value = $_SESSION['varname'];

Remember to run the session_start() ; statement on both these pages before you try to access the $_SESSION array, and also before any output is sent to the browser.

Answer 3

If the parameter must remain invisible in the UI (ie, not in the address bar) and you need to avoid POST requests due to page reloading, you can achieve this with two requests...

Either one AJAX POST then a GET, ie

fetch('set-session-var.php', {
  method: 'post',
  body: 'x=5',
  headers: {
    "Content-Type": "application/x-www-form-urlencoded"
  }
}).then(res => {
  if (res.ok) {
    window.location = 'edit.php'
  }
})

or use a Post / Redirect / Get pattern, eg

<form action="set-session-var.php" method="post">
  <!-- set the "x" value however and whenever you want -->
  <button type="submit" name="x" value="5">Go</button>
</form>

// set-session-var.php
session_start();
$_SESSION['x'] = $_POST['x'];
header('Location: edit.php'); // omit this if using the AJAX version

Answer 4

Use Cookie...

index.php:

setcookie("x", 5);

edit.php:

echo $_COOKIE["x"];