Why Twig filters and not functions?

[mbontemps]

@stof, could you elaborate a bit on why you have chosen to replace a function by a filter, ie:

{% knp_menu_render('main' } %}

has become:

{{ 'main'|knp_menu_render }}

In terms of logic, it is not intuitive to me…

[stof]

It has never been a tag. It was a function: {{ knp_menu(menu) }} in the previous version.
And a filter is more semantic than a function for this as it transform the input into another value (this is also the reason why the date filter is a filter in Twig, not a function)

[benjamindulau]

I agree with @mbontemps, it's not intuitive.

I'm not sure about the semantic thing. A filter transforms or adapts a value that already has a "meaning" (a date for instance).
Here, 'main' is used just to find something, it's not a value intended for display.

It has its place as a function argument => "Go find my menu named 'main' and render it".

[stof]

the filter accept 2 things: the menu object, or the name for the menu in the provider.

[benjamindulau]

Still, IMO perhaps both filter and method should be proposed. The filter transforms a menu object, and the method takes a menu name.

[weaverryan]

I don't think I like having both a filter and a function (which behave differently), but I think that @benjamindulau is perfectly logical: filtering the menu object makes sense, but filter a string into a full menu just doesn't feel right.

Also, I think a function is more consistent with how the Symfony form framework works, and it's also consistent with how you render a menu in PHP (e.g. you pass the menu into a renderer).

So, +1 for making it a function again - I just think it's a little more understandable.

[weaverryan]

Thanks @stof!