How to retrieve all Variables from a Twig Template?

Question

Is it possible to retrieve all variables inside a Twig template with PHP?

Example someTemplate.twig.php:

Hello {{ name }}, 
your new email is {{ ema         


        

Answer 1

If you need all Twig elements inside of a text, just use:

preg_match_all('/\{\%\s*(.*)\s*\%\}|\{\{(?!%)\s*((?:[^\s])*)\s*(?<!%)\}\}/i', $text, $matches);

I had a issue where the WSIWYG editor placed HTML tags inside of Twig variables. I filter them with:

public function cleanHTML($text)
{
    preg_match_all('/\{\%\s*(.*)\s*\%\}|\{\{(?!%)\s*((?:[^\s])*)\s*(?<!%)\}\}/i', $text, $matches);

    if (isset($matches[0]) && count($matches[0])) {
        foreach ($matches[0] as $match) {
            $clean_match = strip_tags($match);

            $text = str_replace($match, $clean_match, $text);
        }
    }

    return $text;
}

UPDATE

Use this expression to find all {{ }} and {% %}

preg_match_all('/\{\%\s*([^\%\}]*)\s*\%\}|\{\{\s*([^\}\}]*)\s*\}\}/i', $text, $matches);

Answer 2

Create a Twig_Extension and add a function with the needs_context flag:

class MyTwigExtension extends Twig_Extension{
   public function getFunctions()
    {
        return array(
            new \Twig_SimpleFunction('myTwigFunction', array($this, 'myTwigFunction'), array('needs_context' => true)),
        );
    }

    public function myTwigFunction($context)
    {
        var_dump($context);
        return '';
    }
}

The context will be passed as first parameter to your function, containing all variables.

On your Twig template you just have to call that function:

{{myTwigFunction()}}

If you need assistance on creating a Twig Extension, please refer to this documentation:

http://twig.sensiolabs.org/doc/2.x/advanced.html

Answer 3

I think 19Gerhard85's answer is pretty good, although it might need some tweaking because it matched some empty strings for me. I like using existing functions where possible and this is an approach mostly using twig's functions. You need access to your application's twig environment.

/**
 * @param $twigTemplateName
 * @return array
 */
public function getRequiredKeys($twigTemplateName)
{
    $twig = $this->twig;
    $source = $twig->getLoader()->getSource($twigTemplateName);
    $tokens = $twig->tokenize($source);
    $parsed = $twig->getParser()->parse($tokens);
    $collected = [];
    $this->collectNodes($parsed, $collected);

    return array_keys($collected);
}

And the only custom part of it is the recursive function to collect only certain types of nodes:

/**
 * @param \Twig_Node[] $nodes
 * @param array $collected
 */
private function collectNodes($nodes, array &$collected)
{
    foreach ($nodes as $node) {
        $childNodes = $node->getIterator()->getArrayCopy();
        if (!empty($childNodes)) {
            $this->collectNodes($childNodes, $collected); // recursion
        } elseif ($node instanceof \Twig_Node_Expression_Name) {
            $name = $node->getAttribute('name');
            $collected[$name] = $node; // ensure unique values
        }
    }
}

Answer 4

$loader1 = new Twig_Loader_Array([
    'blub.html' => '{{ twig.template.code }}',
]);
$twig = new Twig_Environment($loader1);
$tokens = $twig->tokenize($loader1->getSource('blub.html'));
$nodes = $twig->getParser()->parse($tokens);

var_dump($this->getTwigVariableNames($nodes));


function getTwigVariableNames($nodes): array
{
    $variables = [];
    foreach ($nodes as $node) {
        if ($node instanceof \Twig_Node_Expression_Name) {
            $name = $node->getAttribute('name');
            $variables[$name] = $name;
        } elseif ($node instanceof \Twig_Node_Expression_Constant && $nodes instanceof \Twig_Node_Expression_GetAttr) {
            $value = $node->getAttribute('value');
            if (!empty($value) && is_string($value)) {
                $variables[$value] = $value;
            }
        } elseif ($node instanceof \Twig_Node_Expression_GetAttr) {
            $path = implode('.', $this->getTwigVariableNames($node));
            if (!empty($path)) {
                $variables[$path] = $path;
            }
        } elseif ($node instanceof \Twig_Node) {
            $variables += $this->getTwigVariableNames($node);
        }
    }
    return $variables;
}

have fun :-)

Answer 5

This Question has a douplicate – there I found a useful and kind of more powerfull RegEX than above. This one, I've improved to match more precise:

\{\{(?!%)\s* # Starts with {{ not followed by % followed by 0 or more spaces
  ((?:(?!\.)[^\s])*?) # Match anything without a point or space in it
  (\|(?:(?!\.)[^\s])*)? # Match filter within variable
\s*(?<!%)\}\} # Ends with 0 or more spaces not followed by % ending with }}
| # Or
\{%\s* # Starts with {% followed by 0 or more spaces
  (?:\s(?!endfor)|(endif)|(else)(\w+))+ # Match the last word which can not be endfor, endif or else
\s*%\} # Ends with 0 or more spaces followed by %}
# Flags: i: case insensitive matching | x: Turn on free-spacing mode to ignore whitespace between regex tokens, and allow # comments.

Answer 6

After I spent quite a night, trying all the above answers, I realized, for some unexpected reason, regexps did not work at all with my simple templates. They returned junk or partial information. So I decided to go by erasing all the content between tags instead of counting tags ^_^.

I mean, if a template is 'AAA {{BB}} CC {{DD}} {{BB}} SS', I just add '}}' in the beginning of the template and '{{ in the end.... and all the content between }} and {{ I'll just strip out, adding comma in between =>}}{{BB,}}{{DD,}}{{BB,}}{{. Then - just erase }} and {{.

It took me about 15 min to write and test.... but with regexps I've spent about 5 hrs with no success.

/**
 * deletes ALL the string contents between all the designated characters
 * @param $start - pattern start 
 * @param $end   - pattern end
 * @param $string - input string, 
 * @return mixed - string
 */
 function auxDeleteAllBetween($start, $end, $string) {
    // it helps to assembte comma dilimited strings
    $string = strtr($start. $string . $end, array($start => ','.$start, $end => chr(2)));
    $startPos  = 0;
    $endPos = strlen($string);
    while( $startPos !== false && $endPos !== false){
        $startPos = strpos($string, $start);
        $endPos = strpos($string, $end);
        if ($startPos === false || $endPos === false) {
            return $string;
        }
        $textToDelete = substr($string, $startPos, ($endPos + strlen($end)) - $startPos);
        $string = str_replace($textToDelete, '', $string);
    }
    return $string;
}

/**
 * This function is intended to replace
 * //preg_match_all('/\{\%\s*([^\%\}]*)\s*\%\}|\{\{\s*([^\}\}]*)\s*\}\}/i', 
 * which did not give intended results for some reason.
 *
 * @param $inputTpl
 * @return array
 */
private function auxGetAllTags($inputTpl){
   $inputTpl = strtr($inputTpl, array('}}' => ','.chr(1), '{{' => chr(2)));
   return explode(',',$this->auxDeleteAllBetween(chr(1),chr(2),$inputTpl));
}


$template = '<style>
td{border-bottom:1px solid #eee;}</style>
<p>Dear {{jedi}},<br>New {{padawan}} is waiting for your approval: </p>
<table border="0">
<tbody><tr><td><strong>Register as</strong></td><td>{{register_as}}, user-{{level}}</td></tr>
<tr><td><strong>Name</strong></td><td>{{first_name}} {{last_name}}</td></tr>...';

print_r($this->auxGetAllTags($template));

Hope it'll help somebody :)