hurricane hurricane - 29 days ago 10
PHP Question

Could I automatically get a reference of arguments in a PHP function?

Currently, I am reviewing websites written ten years ago. These websites uses the old MySQL API for PHP. PHP hasn't been upgraded since version 5.3, that's why I need to rewrite each database request from the old API to PDO.

The original coder has create for each table an object that wraps INSERT,SELECT and UPDATE requests.

On tables with a lot of rows, it is very painful to quote for each object each argument of each wrapped request, and there a dozen of sites that I must revise !

So, I think about a way to reduce the time spent on quoting each argument of the function by getting these in a loop and quote each of them in two lines of code in each function...

After viewing PHP manual, it seems that there is no way to get a reference of a function arguments. I can copy or count them, but can't get any reference.

Have you got any ideas or tips that will make this job sucks less ?

Here is an example of what I shouldn't do :

public function insert($titre, $tva, $intra, $remise = 0,
$tx_remise = 0, $frais = 0, $code = 0, $nom = '',
$design = '', $adr = '', $cp = '', $ville = '',
$tel = '', $fax = '', $rcs = '', $marq = '',
$marq_g = '')
{
$ville = htmlspecialchars($ville);
$design = htmlspecialchars($design);
$nom = htmlspecialchars($nom);
$adr = htmlspecialchars($adr);
$marq = htmlspecialchars($marq);
$marq_g = htmlspecialchars($marq_g);

$titre = $this->db->quote($titre);
$tva = $this->db->quote($tva);
$intra = $this->db->quote($intra);
$remise = $this->db->quote($remise);
$tx_remise = $this->db->quote($tx_remise);
$frais = $this->db->quote($frais);
$code = $this->db->quote($code);
$cp = $this->db->quote($cp);
$tel = $this->db->quote($tel);
$fax = $this->db->quote($fax);
$rcs = $this->db->quote($rcs);


And what I approximately want to do :

public function insert(...)
{
foreach($function->argumentsReference as $ref)
$ref = quote($ref)


Of course $function isn't a real object, it is just a way to explain my idea with code.

Thanks.

Answer

You can use get_defined_vars to retrieve an associative array of all variables in scope, so as long as you use this at the top of your function then you'll effectively have a named copy of all the function arguments. Note that this is different to using func_get_args, which won't contain any default arguments if not provided in the call.

You can apply some logic to all the arguments (quoting, etc) using something like:

<?php
function foo($a, $b, $c) {
  foreach (get_defined_vars() as $key => $value) {
    ${$key} = $value * 2;
  }

  echo implode(', ', [$a, $b, $c]);
}

foo(1, 2, 3);
// 2, 4, 6
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