2019-06-27-getting-values-of-instance-in-liquid-easily.md

title	date	tags
Getting Values of Instance in Liquid Easily	2019-06-27 19:30:00 +0900	liquid ruby

How to get values (or method? I don't care) in Liquid easily.

If you have code like those:

class Avenger
    attr_reader :name
    def instance(name)
        @name = name
    end
    def has_shield
        true
    end
end

{%- raw -%}
{% if avenger.has_shield %}
    <p>I am {{ avenger.name }}.</p>
{% endif %}
{% endraw -%}

Lite Plan A is Liquid::Drop.

class Avenger < Liquid::Drop
    # Liquid can call methods having no arguments lazily.
    ...
end

Lite Plan B is to_liquid.

class Avenger
    ...
    def to_liquid
        # but calling all of them every time
        {
            'name' => name,
            'has_shield' => has_shield
        }
    end
end