Outputting PHP To Browser Console

Sarfraz Ahmed    April 12, 2015 08:23 PM

Although there exist classes for outputting PHP to browser console such as Google’s PHP Console and certain others, I was looking for a way to output PHP to browser console without including those classes in my PHP files or installing any browser plugin to do the same. Currently, I am working on Facebook application development in which you have to commit/upload the code to check certain output out of PHP unlike offline development where you check the code output before committing it up. This makes Facebook application development a longer process for a developer but you got to live with it because you don’t have a choice.

Anyways, to speed up the code output checking process a little and rather using debug_backtrace, print_r, print, echo, var_dump, etc which you need to remove/comment again, I created a function to get output of PHP on the browser console. One could use error_log function but even that makes you go to your log file and then see the output. Of course, browser needs to support/have the console so that code result is output there. Because IE less than 8 doesn't have console, this won’t work in IE less than 8, though result won’t be affected in it. Notice that you can see console in IE=>8 by pressing F12 key and then going to Script tab where you need to make sure Console tab is selected on the right side.

Here is the function:

 * Logs messages/variables/data to browser console from within php
 * @param $name: message to be shown for optional data/vars
 * @param $data: variable (scalar/mixed) arrays/objects, etc to be logged
 * @param $jsEval: whether to apply JS eval() to arrays/objects
 * @return none
 * @author Sarfraz
 function logConsole($name, $data = NULL, $jsEval = FALSE)
      if (! $name) return false;

      $isevaled = false;
      $type = ($data || gettype($data)) ? 'Type: ' . gettype($data) : '';

      if ($jsEval && (is_array($data) || is_object($data)))
           $data = 'eval(' . preg_replace('#[\s\r\n\t\0\x0B]+#', '', json_encode($data)) . ')';
           $isevaled = true;
           $data = json_encode($data);

      # sanitalize
      $data = $data ? $data : '';
      $search_array = array("#'#", '#""#', "#''#", "#\n#", "#\r\n#");
      $replace_array = array('"', '', '', '\\n', '\\n');
      $data = preg_replace($search_array,  $replace_array, $data);
      $data = ltrim(rtrim($data, '"'), '"');
      $data = $isevaled ? $data : ($data[0] === "'") ? $data : "'" . $data . "'";

$js = <<<JSCODE
 // fallback - to deal with IE (or browsers that don't have console)
 if (! window.console) console = {};
 console.log = console.log || function(name, data){};
 // end of fallback


      echo $js;
 } # end logConsole

Here is an example of how to use it:

$name = 'sarfraz';
$fruits = array("banana", "apple", "strawberry", "pineaple");

$user = new stdClass;
$user->name = "Sarfraz";
$user->desig = "Sr. Software Engineer";
$user->lang = "PHP";

logConsole('$name var', $name, true);
logConsole('An array of fruits', $fruits, true);
logConsole('$user object', $user, true);

It would result in:

enter image description here

Although this does not prevent committing code first to see the code output if you are on facebook application development but it defintely does save some time. I have been using this function successfully so far, please let me know your ideas if any on how to improve this piece of code further.

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