slice theme helper

[muratcorlu]

slice helper is a very useful helper for theme developers to do stuff while generating their HTML.

most common requirement is having hierarchical navigations. Currenytly many theme developers fixes this with client-side JS which is not a convenient solution.

Example, partial navigation menu:

Using a part of navigation in a specific place. If a secondary navigation item label starts with @ , then list them in a specific place.

<h2>Find me on other places:</h2>
<ul>
  {{#foreach @site.secondary_navigation}}
    {{#match (slice label start=0 end=2) "@ " }}
      <li><a href="{{url}}">{{ slice label start=2 }}</a></li>
    {{/match}}
  {{#foreach}}
</ul>

Example, hierarchical menu

This notation suggests to have a hierarchical menu by navigation labels like below:

Home
Services [
Software Development
Marketing
Design
] Contact

<ul>
  {{#foreach @site.navigation}}
    {{#match (slice label start=-1) "[" }}
        <li><a href="{{url}}">{{ slice label start=0 end=-2 }}</a></li>
        <ul>
    {{else}}
        {{#match (slice label start=0 end=1) "]" }}
            </ul>
            <li><a href="{{url}}">{{ slice label start=2 }}</a></li>
        {{else}}
             <li><a href="{{url}}">{{ label }}</a></li>
        {{/match}
    {{/match}}
  {{#foreach}}
</ul>

There can be also other smart use cases with a naming convention used with internal tags.

I hope you consider my proposal.

Thanks in advance!

[cathysarisky]

I think you'll also need to add it to the list of helpers. See this recent PR for an example:
https://github.com/TryGhost/Ghost/pull/21151/files

[muratcorlu]

Thank you @cathysarisky . I updated helper test file as well.