“Begins with” in Twig template

Question

I have a twig template where I would like to test if an item begins with a certain value

{% if item.ContentTypeId == \'0x0120\' %}
    

        

Answer 1

You can just use the slice filter. Simply do:

{% if item.ContentTypeId[:6] == '0x0120' %}
{% endif %}

Answer 2

Yes, Twig supports regular expressions in comparisons: http://twig.sensiolabs.org/doc/templates.html#comparisons

In your case it would be:

{% if item.ContentTypeId matches '/^0x0120.*/' %}
  ...
{% else %}
  ...
{% endif %}

Answer 3

You can do that directly in Twig now:

{% if 'World' starts with 'F' %}
{% endif %}

"Ends with" is also supported:

{% if 'Hello' ends with 'n' %}
{% endif %}

---

Other handy keywords also exist:

Complex string comparisons:

{% if phone matches '{^[\\d\\.]+$}' %} {% endif %}

(Note: double backslashes are converted to one backslash by twig)

String contains:

{{ 'cd' in 'abcde' }}
{{ 1 in [1, 2, 3] }}

See more information here: http://twig.sensiolabs.org/doc/templates.html#comparisons

Answer 4

You can always make your own filter that performs the necessary comparison.

As per the docs:

When called by Twig, the PHP callable receives the left side of the filter (before the pipe |) as the first argument and the extra arguments passed to the filter (within parentheses ()) as extra arguments.

So here is a modified example.

Creating a filter is as simple as associating a name with a PHP callable:

// an anonymous function
$filter = new Twig_SimpleFilter('compareBeginning', function ($longString, $startsWith) {
    /* do your work here */
});

Then, add the filter to your Twig environment:

$twig = new Twig_Environment($loader);
$twig->addFilter($filter);

And here is how to use it in a template:

{% if item.ContentTypeId | compareBeginning('0x0120') == true %}
{# not sure of the precedence of | and == above, may need parentheses #}

I'm not a PHP guy, so I don't know how PHP does regexes, but the anonymous function above is designed to return true if $longString begins with $startsWith. I'm sure you'll find that trivial to implement.