Could you tell how to replace by regular expression - php

Question

Could you tell how to replace string by preg-replace (need regular expression):
/user/{parent_id}/{action}/step/1
At the equivalent values of an array:
array('parent_id'=>32, 'action'=>'some');
To make:
/user/32/some/step/1
Addition
This is a typical problem, so I probably will not know what the names of variables come

Answer 1

You can use str_replace
For example:
str_replace(array("{parent_id}", "{action}"), array(32, 'some'), "/user/{parent_id}/{action}/step/1");

Answer 2

$arr = array('parent_id'=>32, 'action'=>'some');
$out = str_replace(array_keys($arr),array_values($arr),$in);
no need for regexps!

Answer 3

Say you have:
$arr = array('parent_id'=>32, 'action'=>'some');
$in = '/usr/{parent_id}/{action}/step/1';
This will replace the braces:
function bracelize($str) {
return '{' . $str . '}';
}
$search = array_map('bracelize', array_keys($arr));
$out = str_replace($search, $arr, $in);
Or if you are using PHP >= 5.3 you can use lambdas:
$search = array_map(function ($v) { return '{'.$v.'}';}, array_keys($arr));
$out = str_replace($search, $arr, $in);

Answer 4

$s = '/user/{parent_id}/{action}/step/1';
$replacement = array('parent_id'=>32, 'action'=>'some');
$res = preg_replace(array('/\\{parent_id\\}/', '/\\{action\\}/'), $replacement, $s);
Of course, you could just as well use str_replace (in fact, you ought to).

Answer 5

<?php
$string = '/usr/{parent_id}/{action}/step/1';
$pattern = array('#{parent_id}#', '#{action}#');
$values = array('32', 'some');
echo preg_replace($pattern, $values, $string);
?>
If your problem is not more complicated than this, i would recommend changing preg_replace to str_replace though.
EDIT: I see you don't know the variable names in advance. In which case you could do something like this.
<?php
function wrap_in_brackets(&$item)
{
$item = '{' . $item . '}';
return true;
}
$string = '/usr/{parent_id}/{action}/step/1';
$variables = array('parent_id' => 32, 'action' => 'some');
$keys = array_keys($variables);
array_walk($keys, 'wrap_in_brackets');
echo str_replace($keys, array_values($variables), $string);
?>

Answer 6

Expanding on mvds' answer:
$in = 'user/{parent_id}/{action}/step/1';
$arr = array('{parent_id}' => 32, '{action}' => 'some');
$out = str_replace(array_keys($arr), $arr, $in);
Or:
$in = 'user/{parent_id}/{action}/step/1';
$arr = array('parent_id' => 32, 'action' => 'some');
$arr[] = '';
$find = array_merge(array_keys($arr), array('{', '}'));
$out = str_replace($find, $arr, $in);