Question

This is a generalization of my previous question about pluralize filter:

Does lift have an equivalent of Django’s tags and filters?

Tags are small piece of predefined code that can be used directly in html template, for example:

{% now "jS F Y H:i" %}

renders the time right now in the given format.

Filters

Filters operate (in html template) on the context variables in the template, for example:

{{ value|capfirst }}

if called on a value “john” will result in “John”. Or:

{{ value|length }}

will render the length of the string into the template.

As you can see the filters operate on the context variables that are passed to the template.

Answer 1

Considering tags, you could define those yourself with snippets.

As snippet is basically a callback much as a Django tag is. You don’t get any easier syntax, though, because Lift’s templates are pure XML/Html.

<Lift:Tag.now format="jS F Y H:i" />

And the logic would be defined in

class Tag {
  def now: NodeSeq = // ...
}

---

Filtering is something you generally can’t do in a Lift template because Lift doesn’t allow any variables in a template. The whole concept is thus inapplicable. (You could do XML transforms or or bind magic but that would be a bit too much for a simple value.length.)

No, if you need the length of some value in your Html, you will have to define that inside the snippet and expose it.

If you really can’t live without filters in your template (though I can assure you, it is a good thing to separate all HTML template and code and it works once you are used to it), have a look at Scalate which may be used together with Lift as well.