How can I call PHP functions by JavaScript?


I am trying to call a PHP function from an external PHP file into a JavaScript script. My code is different and large, so I am writing a sample code here.

This is my PHP code:

<?php
function add($a,$b){
  $c=$a+$b;
  return $c;
}
function mult($a,$b){
  $c=$a*$b;
  return $c;
}

function divide($a,$b){
  $c=$a/$b;
  return $c;
}
?>

This is my JavaScript code:

<script>
  var phpadd= add(1,2); //call the php add function
  var phpmult= mult(1,2); //call the php mult function
  var phpdivide= divide(1,2); //call the php divide function
</script>

So this is what I want to do.

My original PHP file doesn't include these mathematical functions but the idea is same.

If some how it doesn't have a proper solution, then may you please suggest an alternative, but it should call values from external PHP.

Yes, you can do ajax request to server with your data in request parameters, like this (very simple):

Note that the following code uses jQuery

jQuery.ajax({
    type: "POST",
    url: 'your_functions_address.php',
    dataType: 'json',
    data: {functionname: 'add', arguments: [1, 2]},

    success: function (obj, textstatus) {
                  if( !('error' in obj) ) {
                      yourVariable = obj.result;
                  }
                  else {
                      console.log(obj.error);
                  }
            }
});

and your_functions_address.php like this:

    <?php
    header('Content-Type: application/json');

    $aResult = array();

    if( !isset($_POST['functionname']) ) { $aResult['error'] = 'No function name!'; }

    if( !isset($_POST['arguments']) ) { $aResult['error'] = 'No function arguments!'; }

    if( !isset($aResult['error']) ) {

        switch($_POST['functionname']) {
            case 'add':
               if( !is_array($_POST['arguments']) || (count($_POST['arguments']) < 2) ) {
                   $aResult['error'] = 'Error in arguments!';
               }
               else {
                   $aResult['result'] = add(floatval($_POST['arguments'][0]), floatval($_POST['arguments'][1]));
               }
               break;

            default:
               $aResult['error'] = 'Not found function '.$_POST['functionname'].'!';
               break;
        }

    }

    echo json_encode($aResult);

?>

Try This

<script>
  var phpadd= <?php echo add(1,2);?> //call the php add function
  var phpmult= <?php echo mult(1,2);?> //call the php mult function
  var phpdivide= <?php echo divide(1,2);?> //call the php divide function
</script>

use document.write for example,

<script>
  document.write(' <?php add(1,2); ?> ');
  document.write(' <?php milt(1,2); ?> ');
  document.write(' <?php divide(1,2); ?> ');
</script>

You need to create an API : Your js functions execute AJAX requests on your web service

  var mult = function(arg1, arg2)
    $.ajax({
      url: "webservice.php?action=mult&arg1="+arg1+"&arg2="+arg2
    }).done(function(data) {
      console.log(data);
    });
  }

on the php side, you'll have to check the action parameter in order to execute the propre function (basically a switch statement on the $_GET["action"] variable)


index.php

<body>
...
<input id="Div7" name="Txt_Nombre" maxlenght="100px" placeholder="Nombre" />
<input id="Div8" name="Txt_Correo" maxlenght="100px" placeholder="Correo" />
<textarea id="Div9" name="Txt_Pregunta" placeholder="Pregunta" /></textarea>

<script type="text/javascript" language="javascript">

$(document).ready(function() {
    $(".Txt_Enviar").click(function() { EnviarCorreo(); });
});

function EnviarCorreo()
{
    jQuery.ajax({
        type: "POST",
        url: 'servicios.php',
        data: {functionname: 'enviaCorreo', arguments: [$(".Txt_Nombre").val(), $(".Txt_Correo").val(), $(".Txt_Pregunta").val()]}, 
         success:function(data) {
        alert(data); 
         }
    });
}
</script>

servicios.php

<?php   
    include ("correo.php");

    $nombre = $_POST["Txt_Nombre"];
    $correo = $_POST["Txt_Corro"];
    $pregunta = $_POST["Txt_Pregunta"];

    switch($_POST["functionname"]){ 

        case 'enviaCorreo': 
            EnviaCorreoDesdeWeb($nombre, $correo, $pregunta);
            break;      
    }   
?>

correo.php

<?php
    function EnviaCorreoDesdeWeb($nombre, $correo, $pregunta)
    { 
       ...
    }
?>

If you actually want to send data to a php script for example you can do this:

The php:

<?php
$a = $_REQUEST['a'];
$b = $_REQUEST['b']; //totally sanitized

echo $a + $b;
?>

Js (using jquery):

$.post("/path/to/above.php", {a: something, b: something}, function(data){                                          
  $('#somediv').html(data);
});

This work perfectly for me:

To call a PHP function (with parameters too) you can, like a lot of people said, send a parameter opening the PHP file and from there check the value of the parameter to call the function. But you can also do that lot of people say it's impossible: directly call the proper PHP function, without adding code to the PHP file.

I found a way:

This for JavaScript:

function callPHP(expression, objs, afterHandler) {
        expression = expression.trim();
        var si = expression.indexOf("(");
        if (si == -1)
            expression += "()";
        else if (Object.keys(objs).length > 0) {
            var sfrom = expression.substring(si + 1);
            var se = sfrom.indexOf(")");
            var result = sfrom.substring(0, se).trim();
            if (result.length > 0) {
                var params = result.split(",");
                var theend = expression.substring(expression.length - sfrom.length + se);
                expression = expression.substring(0, si + 1);
                for (var i = 0; i < params.length; i++) {
                    var param = params[i].trim();
                    if (param in objs) {
                        var value = objs[param];
                        if (typeof value == "string")
                            value = "'" + value + "'";
                        if (typeof value != "undefined")
                            expression += value + ",";
                    }
                }
                expression = expression.substring(0, expression.length - 1) + theend;
            }
        }
        var doc = document.location;
        var phpFile = "URL of your PHP file";
        var php =
            "$docl = str_replace('/', '\\\\', '" + doc + "'); $absUrl = str_replace($docl, $_SERVER['DOCUMENT_ROOT'], str_replace('/', '\\\\', '" + phpFile + "'));" +
            "$fileName = basename($absUrl);$folder = substr($absUrl, 0, strlen($absUrl) - strlen($fileName));" +
            "set_include_path($folder);include $fileName;" + expression + ";";
        var url = doc + "/phpCompiler.php" + "?code=" + encodeURIComponent(php);
        $.ajax({
            type: 'GET',
            url: url,
            complete: function(resp){
                var response = resp.responseText;
                afterHandler(response);
            }
        });
    }


This for a PHP file which isn't your PHP file, but another, which path is written in url variable of JS function callPHP , and it's required to evaluate PHP code. This file is called 'phpCompiler.php' and it's in the root directory of your website:

<?php
$code = urldecode($_REQUEST['code']);
$lines = explode(";", $code);
foreach($lines as $line)
    eval(trim($line, " ") . ";");
?>


So, your PHP code remain equals except return values, which will be echoed:

<?php
function add($a,$b){
  $c=$a+$b;
  echo $c;
}
function mult($a,$b){
  $c=$a*$b;
  echo $c;
}

function divide($a,$b){
  $c=$a/$b;
  echo $c;
}
?>


I suggest you to remember that jQuery is required:
Download it from Google CDN:

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>

or from Microsoft CDN: "I prefer Google! :)"

<script src="https://ajax.aspnetcdn.com/ajax/jQuery/jquery-3.1.1.min.js"></script>

Better is to download the file from one of two CDNs and put it as local file, so the startup loading of your website's faster!

The choice is to you!


Now you finished! I just tell you how to use callPHP function. This is the JavaScript to call PHP:

//Names of parameters are custom, they haven't to be equals of these of the PHP file.
//These fake names are required to assign value to the parameters in PHP
//using an hash table.
callPHP("add(num1, num2)", {
            'num1' : 1,
            'num2' : 2
        },
            function(output) {
                alert(output); //This to display the output of the PHP file.
        });

I wrote some script for me its working .. I hope it may useful to you

<?php
if(@$_POST['add'])
{
function add()
{
   $a="You clicked on add fun";
   echo $a;
}
add();
}
else if (@$_POST['sub']) 
{
function sub()
{
   $a="You clicked on sub funn";
echo $a;  
}
sub();  
}
?>
<form action="<?php echo $_SERVER['PHP_SELF'];?>" method="POST">

<input type="submit" name="add" Value="Call Add fun">
<input type="submit" name="sub" Value="Call Sub funn">
<?php echo @$a; ?>

</form>

Try looking at CASSIS. The idea is to mix PHP with JS so both can work on client and server side.


I created this library JS PHP Import which you can download from github, and use whenever and wherever you want.

The library allows importing php functions and class methods into javascript browser environment thus they can be accessed as javascript functions and methods by using their actual names. The code uses javascript promises so you can chain functions returns.

I hope it may useful to you.

Example:

<script>
$scandir(PATH_TO_FOLDER).then(function(result) {
  resultObj.html(result.join('<br>'));
});

$system('ls -l').then(function(result) {
  resultObj.append(result);
});

$str_replace(' ').then(function(result) {
  resultObj.append(result);
});

// Chaining functions 
$testfn(34, 56).exec(function(result) { // first call
   return $testfn(34, result); // second call with the result of the first call as a parameter
}).exec(function(result) {
   resultObj.append('result: ' + result + '<br><br>');
});
</script>

I created this library, may be of help to you. MyPHP client and server side library

Example:

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <title>Page Title</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body>

    <!-- include MyPHP.js -->
    <script src="MyPHP.js"></script>

    <!-- use MyPHP class -->
    <script>
        const php = new MyPHP;
        php.auth = 'hashed-key';

        // call a php class
        const phpClass = php.fromClass('Authentication' or 'Moorexa\\Authentication', <pass aguments for constructor here>);

        // call a method in that class
        phpClass.method('login', <arguments>);

        // you can keep chaining here...

        // finally let's call this class
        php.call(phpClass).then((response)=>{
            // returns a promise.
        });

        // calling a function is quite simple also
        php.call('say_hello', <arguments>).then((response)=>{
            // returns a promise
        });

        // if your response has a script tag and you need to update your dom call just call
        php.html(response);

    </script>
</body>
</html>