Guide 34 – Basic method for code debugging

I normally use an IDE environment to debug the code generated by PHPRunner ( MS Visual Studio and Netbeans PHP ).

I can only do this on my PC, since on it I configure Apache and the PHP environment to what I need, but I cannot do this on the servers where I upload the applications and where I do not have control of the entire environment .

For these cases where I cannot configure my IDE and also, for those users who have not yet taken the step to have an IDE for PHP debugging, we can use a very simple method that I am going to explain to you.

The method consists of writing to a file (in this case called “error.log”) that is accessible from any browser. In this way, everything we write in said file can be consulted and it will give us a clue about our problems.

To mount the system we have to do:

• Create a file called “error.log” in the root of our project. For example, if my project has a path of the type “../apache/htdoc/project1”, we will create the file “../apache/htdoc/project1/error.log”

  
  

• In our PHPRunner project we will insert this code in the “After application initialized” event. This event is executed in all the requests that we make to the application.

  // To debug PHP code on the server
function custom_error($number,$text){ // Function to produce the error file
global $debugCode;
if ($debugCode == true ) {
$ddf = fopen(__DIR__ .'/../error.log','a');
fwrite($ddf,"[".date("r")."] Error $number: $text\r\n");
fclose($ddf);
}
}
$debugCode = true;
custom_error(1,"URL ejecutada: ".$_SERVER["REQUEST_URI"]); // To debug

  If we want it not to write new traces we will set the $debugCode variable to false.
  We will also delete the “error.log” file on Production systems

  
  

• Every time we want to write the content of a variable or object, we will use the custom_error() function. For example (see what SQL is being executed. include in the “Before SQL query” event:

  custom_error(2,"SQL de v_resource: ".$strSQL); // To debug
custom_error(2,"WHERE de v_resource: ".$strWhereClause); // To debug
  

The result of the file is like this:

I hope you find it useful and for any help or suggestion you can contact me through my email fernandohumanes@gmail.com