How to 'console log' PHP code in Chrome or Firefox? - php

Question

I've been looking up how I can debug PHP code in Chrome or Firefox but I can;t really find a solution. This is my PHP:
<?php
if(isset($_POST["data"]))
{
$var = $_POST["data"];
print "your message: " . $_POST["data"];
if(!empty($_POST['ip.data'])){
$data = $_POST['ip.data'];
$fname = mktime() . ".txt";//generates random name
$file = fopen("upload/" .$fname, 'w');//creates new file
fwrite($file, $data);
fclose($file);
}
}
?>
I want to be able to see the output of print "your message: " . $_POST["data"]; or any errors in Chrome or Firefox. I've tried Firefox Quantum that should be able to debug php? Anyways, how can I console log this?

Answer 1

The first step is to recognize that PHP, which is generally a server side language is a completely different context than the browser's console, which is fundamentally Javascript. Thus, to show messages to the browser's console from the server, you will need to find some way to communicate those messages (e.g., errors) to the browser.
At that point, you might consider something as simple as embedding a script tag with your PHP:
function debugToBrowserConsole ( $msg ) {
$msg = str_replace('"', "''", $msg); # weak attempt to make sure there's not JS breakage
echo "<script>console.debug( \"PHP DEBUG: $msg\" );</script>";
}
function errorToBrowserConsole ( $msg ) {
$msg = str_replace('"', "''", $msg); # weak attempt to make sure there's not JS breakage
echo "<script>console.error( \"PHP ERROR: $msg\" );</script>";
}
function warnToBrowserConsole ( $msg ) {
$msg = str_replace('"', "''", $msg); # weak attempt to make sure there's not JS breakage
echo "<script>console.warn( \"PHP WARNING: $msg\" );</script>";
}
function logToBrowserConsole ( $msg ) {
$msg = str_replace('"', "''", $msg); # weak attempt to make sure there's not JS breakage
echo "<script>console.log( \"PHP LOG: $msg\" );</script>";
}
# Convenience functions
function d2c ( $msg ) { debugToBrowserConsole( $msg ); }
function e2c ( $msg ) { errorToBrowserConsole( $msg ); }
function w2c ( $msg ) { warnToBrowserConsole( $msg ); }
function l2c ( $msg ) { logToBrowserConsole( $msg ); }
if ( 'POST' === $_SERVER['REQUEST_METHOD'] ) {
if ( isset( $_POST['data'] ) ) {
d2c( "Your message: {$_POST['data']}"
e2c( "This is an error from PHP" );
w2c( "This is a warning from PHP" );
l2c( "This is a log message from PHP" );
...
}
}
But this will be a fundamentally weak and brittle approach. I would suggest instead tailing your log files on the server directly. If you are after some color, consider using clog, lwatch, or grc:
$ grc tail -f /var/log/syslog

Answer 2

echo "console.log( 'Debug Objects: " . $output . "' );";

Answer 3

I ran through the same problem recently, just couldn't find a simple enough way without installing some large external package.
I first tried the obvious way:
<?php echo "<script>console.log(".$myVar.")<script>" ?>
but it only works with scalar types. For example:
<?php
$arr = [ 'x' => 42 ];
echo "<script>console.log(".$arr.")</script>";
?>
will output to the html
<script>console.log(Array)</script>
a solution to this is to use json_encode on the variable in the php side, then JSON.parse it in the javascript and finally console.log.
However this approach fails to capture non public properties of objects:
<?php
class Test {
private $x = 42;
public $y = 13;
}
$obj = json_encode(new Test());
echo "<script>console.log(JSON.parse('".$obj."'))</script>";
?>
will output to the browser console:
{y: 13}
Because private/protected fields can't be accessed by json_encode.
The solution here is either to add a __toString method to your class where you properly expose those fields as strings, or use some hack like calling var_export then process the output string to make it json_encode-able.
I ended up writing a small helper using the latter approach, and an output prettifier in the javascript side
Leaving the link here if anyone wants to use it.

Answer 4

If you want to see errors on an Ubuntu machine and you run an Apache server, you can constantly monitor and output changes to the error.log file in the apache folder with this command:
tail -f /var/log/apache2/error.log
If you have a server running on apache then this will output any errors occurred.
The tail command simply outputs the last 10 lines of a file and updates when new data is piped into the file.

Answer 5

I hope will help:
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

Answer 6

Try this
<?php
function temp()
{
if(isset($_POST["data"]))
{
$var = $_POST["data"];
print "your message: " . $_POST["data"];
if(!empty($_POST['ip.data'])){
$data = $_POST['ip.data'];
$fname = mktime() . ".txt";//generates random name
$file = fopen("upload/" .$fname, 'w');//creates new file
fwrite($file, $data);
fclose($file);
}
}
}//function
?>
<script>
console.log(".<?php temp(); ?>.");
</script>

Answer 7

On Chrome, you can use phpconsole which works quite well.
If anybody knows of something similar for Firefox Quantum please comment.