Convert string to multidimensional array without eval - php

Question

I saved template-variables in the DB, e.g.: slider.item1.headline1 = "Headline1".
I am using symfony framework. If I just pass "slider.item1.headline1" to the Twig template, that won't be used because the points are interpreted as a multidimensional array (or nested object) (https://symfony.com/doc/current/templates.html#template-variables).
I've now built a routine that converts the string into a multidimensional array.
But I don't like the eval(), PHP-Storm doesn't like it either, marks it as an error.
How could this be solved in a nicer way (without eval)?
Here my method:
protected function convertTemplateVarsFromDatabase($tplvars): array
{
$myvar = [];
foreach ($tplvars as $tv)
{
$handle = preg_replace('/[^a-zA-Z0-9._]/', '_', $tv['handle']);
$tplsplit = explode('.', $handle);
$mem = "";
foreach ($tplsplit as $eitem)
{
$mem .= "['" . $eitem . "']";
}
$content = $tv['htmltext'];
eval('$myvar' . $mem . ' = $content;');
}
return $myvar;
}

Answer 1

You can indeed avoid eval here. Maintain a variable that follows the existing array structure of $myvar according to the path given, and let it create any missing key while doing so. This is made easier using the & syntax, so to have a reference to a particular place in the nested array:
function convertTemplateVarsFromDatabase($tplvars): array
{
$myvar = [];
foreach ($tplvars as $tv)
{
$handle = preg_replace('/[^a-zA-Z0-9._]/', '_', $tv['handle']);
$tplsplit = explode('.', $handle);
$current = &$myvar;
foreach ($tplsplit as $eitem)
{
if (!isset($current[$eitem])) $current[$eitem] = [];
$current = &$current[$eitem];
}
$current = $tv['htmltext'];
}
return $myvar;
}