Extending Timber

Question

I'm using Timber for the first time, and I find that it is hard to convert my pure PHP thinking to this templating model.

What I'm confused about at the moment is using a date which is an input field, not the post date.

So I've got a repeater field from ACF. It has three sub-fields: release_date, document_file, and document_title. My release date format is YYYY-MM-DD.

As you might have guessed, this repeater field is output as a list of PDFs.

So far so good, but then I want some advanced functionality - namely, to have the PDFs display by release_date by default. I also want to be able to filter by the year, i.e. - if you click "2015", it would only show the documents from that year.

I know exactly how I would do this in straight WordPress, but I'm pretty confused making it on Timber. I've been trying to do it using a custom filter, but I have felt what I actually want is a custom class?

In addition, when I installed Timber it didn't come with the starter theme, so I did a search and downloaded one from GitHub. I've got a feeling this is a legacy version though, because the file structure and syntax doesn't seem to match the documentation.

Downloaded from here: https://github.com/timber/starter-theme

But for example this code in the starter theme functions.php:

function add_to_twig( $twig ) {
    /* this is where you can add your own functions to twig */
    $twig->addExtension( new Twig_Extension_StringLoader() );
    $twig->addFilter('split_date', new Twig_SimpleFilter('split_date', array($this, 'split_date')));
    return $twig;
}

Doesn't quite match the syntax in https://github.com/timber/timber/wiki/Extending-Timber under "Adding to Twig".

The syntax for adding the filter is a bit different but still correct. Using array($this, 'split_date)` is equal telling to twig: Add a new filter split_date and allocate it the function based in $this class. The example in the documentation is using global functions instead of class methods — DarkBee
OK, cool, so that's not deprecated. Is it a reasonable way of doing what I'm trying to achieve, though? I want to be able to split the date (hence split_date) and use day, year and month separately. — rickibarnes
If your releasedate is a valid date string i'd go with : <a href="route/to/file?year={{ release_date | date('Y') }}">{{ release_date | date('Y-m-d') }}</a> — DarkBee
Have just come to this discovery myself thanks to looking at footer.twig for the first time. That is exactly what I'm looking for, cheers. It is perfectly nice and simple, though I'm still a little confused by the documentation. I didn't see that syntax in the examples anywhere. — rickibarnes
You can see the different methods of adding filters to twig in their document over here — DarkBee

Adam Genshaft Adam Genshaft · Accepted Answer · 2017-05-14T07:13:42

Here are a few helper functions to make it easy for me to extend timber.

function add_context_var( $key, $var ) {
    add_filter( 'timber_context', function ( $context ) use ( $key, $var ) {
        $context[ $key ] = $var;

        return $context;
    } );
}

function add_context_func( $key, $callback ) {
    add_filter( 'timber/twig', function ( $twig ) use ( $key, $callback ) {
        $twig->addFunction( new \Twig_SimpleFunction( $key, $callback ) );

        return $twig;
    } );
}

function add_to_context( $key, $val ) {
    if ( is_callable( $val ) ) {
        add_context_func( $key, $val );
    } else {
        add_context_var( $key, $val );
    }
}

function add_to_context_filter( $key, $callback ) {
    add_filter( 'get_twig', function ( $twig ) use ( $key, $callback ) {
        $twig->addExtension( new Twig_Extension_StringLoader() );
        $twig->addFilter( new Twig_SimpleFilter( $key, $callback ) );

        return $twig;
    } );
}

//php file
add_to_context("blue", "this key is blue")
add_to_context("red", function($extra = ""){
  return "this key is red and it has $extra";
})
add_to_context_filter( "relative_link", function ( $content ) {
    return str_replace( "http://", "//", $content );;
} );

//twig file
color: {{ blue }}
color: {{ red("a function parameter") }}
github: {{ "http://github.com/"|relative_link }}

//output html
color: this key is blue
color: this key is red and it has function parameter
github: //github.com/

Extending Timber

1 Answers