group_by filter

[jesseditson]

Would make certain site types a little easier. For instance, tags on a blog post.

Current solution:

{% assign groups_str = '' %}
{% for t in post.tags %}
  {% assign group = t.name | prepend: ',' %}
  {% unless groups_str contains group %}
    {% assign groups_str = groups_str | append: group %}
  {% endunless %}
{% endfor %}
{% assign groups = groups_str | remove_first: ',' | split: ',' %}

{% for group in groups %}
  {{group}}
{% endfor %}

The implied data model is:

[post]
[post.tags]
name = "string"

Which (somewhat annoyingly) expands to

// my-post.toml

[[tags]]
name = "foo"

[[tags]]
name = "bar"

A string array type would further simplify definition but is not currently planned.