passing the result of a boolean expression to a twig function

Question

I have a custom function that's being added to the Twig object like so:

...
    add_filter('get_twig', array(get_class(),'add_twig_functions'));
...

public static function add_twig_functions($twig)
{
    $twig->addFunction(new Twig_SimpleFunction('get_table', array(get_class(), 'get_table')));

    return $twig;
}

...

public static function get_table($cycle, $visible = true, $id = null)
{
    ....
}

Inside a twig template, I am trying to call it like so:

{{ get_table('mth', user_data.cycle = 'Monthly', 'table-mth') }}

However I'm getting an error:

PHP Fatal error: Uncaught exception 'Twig_Error_Syntax' with message 'A parameter name must be a string, "Twig_Node_Expression_GetAttr" given

My intended result is that the $visible parameter is passed as true if the user_data.cycle context variable is equal to 'Monthly', but clearly I'm not doing it correctly.

I also tried changing my call to:

{{ get_table('mth', (user_data.cycle = 'Monthly'), 'table-mth') }}

However this just gives me:

PHP Fatal error: Uncaught exception 'Twig_Error_Syntax' with message 'An opened parenthesis is not properly closed. Unexpected token "operator" of value "=" ("punctuation" expected with value ")")

Is there an expected way to pass a boolean expression to a twig function? Timber is at version 1.1.6, for what it's worth. All the documentation I've been able to find so far on extending with functions is at http://twig.sensiolabs.org/doc/advanced.html, but it doesn't really cover parameters.

Chris O'Kelly Chris O'Kelly · Accepted Answer · 2016-10-20T23:14:32

Well this is just me misremembering how comparisons work in twig... I had the impression that = in Twig was the equivalent of PHP's ==, and == in twig was the equivalent of PHP's ===, but I don't know where I got that impression because it's wrong.

{{ get_table('mth', (user_data.cycle == 'Monthly'), 'table-mth') }}

works fine and as expected. There goes a pointless hour of troubleshooting.

passing the result of a boolean expression to a twig function

1 Answers