[php] How to call a php script/function on a html button click

Before someone has a go at me or marks this down, I have looked all over the internet to find out how to do this (including the same question on stackoverflow). I'm new, and I am finding it very hard to learn new concepts so please be easy on me.

What I want to do is call a php script/function on a button click. I have this running in WAMP if that helps. Here's my code:

<?php include 'the_script.php'; ?>

<button type="button" onclick="the_function()">Click Me</button>

the_script.php has this in it:

the_function() {
    echo "You win";
}

Why isn't this working? I've heard about the button being client side etc. and PHP being server-side, which means that you cannot link the two together. I know that you have to use AJAX to make this work, however I legitimately have absolutely no clue how to do it. I've tried googling it etc., however I can't find anything. I know how to use AJAX and call events with it, however I still have no idea how to make it call a PHP script.

Can you please make your answers as clear and simple as possible, I'm new to this

Thanks for the help :)

EDIT ***

For some reason wherever I go everyone's code is different. The way I have been taught AJAX looks completely different. Can you please write it this way so I can understand? Thanks, here's an example:

var request;

if (window.XMLHttpRequest) {
    request = new XMLHttpRequest();
} else {
    request = new ActiveXObject("Microsoft.XMLHTTP");
}

request.open('GET', 'file.php', true);

request.onreadystatechange = function() {

    if (request.readyState===4 && request.status===200) {
        do stuff
    }
}

request.send();

Of course AJAX is the solution,

To perform an AJAX request (for easiness we can use jQuery library).

Step1.

Include jQuery library in your web page

a. you can download jQuery library from jquery.com and keep it locally.

b. or simply paste the following code,

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js"></script>

Step 2.

Call a javascript function on button click

<button type="button" onclick="foo()">Click Me</button>

Step 3.

and finally the function

 function foo () {
      $.ajax({
        url:"test.php", //the page containing php script
        type: "POST", //request type
        success:function(result){
         alert(result);
       }
     });
 }

it will make an AJAX request to test.php when ever you clicks the button and alert the response.

For example your code in test.php is,

<?php echo 'hello'; ?>

then it will alert "hello" when ever you clicks the button.

You can also use

   $(document).ready(function() {

    //some even that will run ajax request - for example click on a button

    var uname = $('#username').val();
    $.ajax({
    type: 'POST',
    url: 'func.php', //this should be url to your PHP file
    dataType: 'html',
    data: {func: 'toptable', user_id: uname},
    beforeSend: function() {
        $('#right').html('checking');
    },
    complete: function() {},
    success: function(html) {
        $('#right').html(html);
    }
    });

    });
And your func.php:

  function toptable()
 {
  echo 'something happens in here';
 }

Hope it helps somebody

the_function() {

$.ajax({url:"demo_test.php",success:function(result){

   alert(result); // will alert 1

 }});

}

// demo_test.php

<?php echo 1; ?>

Notes

1. Include jquery library for using the jquery Ajax
2. Keep the demo_test.php file in the same folder where your javascript file resides

Use jQuery.In the HTML page -

<button type="button">Click Me</button>

<script>
$(document).ready(function() {
$("button").click(function(){
  $.ajax({
    url:"php_page.php", //the page containing php script
    type: "POST", //request type
    success:function(result){
    alert(result);
    }
  });
});
})
</script>

Php page -

echo "Hello";

First understand that you have three languages working together.

PHP: Is only run by the server and responds to requests like clicking on a link (GET) or submitting a form (POST). HTML & Javascript: Is only run in someone's browser (excluding NodeJS) I'm assuming your file looks something like:

<?php
function the_function() {
echo 'I just ran a php function';
 }

 if (isset($_GET['hello'])) {
  the_function();
  }
   ?>
  <html>
 <a href='the_script.php?hello=true'>Run PHP Function</a>
 </html>

Because PHP only responds to requests (GET, POST, PUT, PATCH, and DELETE via $_REQUEST) this is how you have to run a php function even though their in the same file. This gives you a level of security, "Should I run this script for this user or not?".

If you don't want to refresh the page you can make a request to PHP without refreshing via a method called Asynchronous Javascript and XML (AJAX).

Modify the_script.php like this.

<script>
the_function() {
    alert("You win");
}
</script>