Roasters by State

state.njk

---js
{
  pagination: {
    // Go over the roaster data
    data: "roasters",
    // Convert the list of roaster to {[state]: {name: string, roasters: Array<Roaster>}}
    // (You could do without the {name, roasters} and only have data, but then the iteration is uglier imo)
    before: function(roasters) {
      let roastersByState = {};
      for (let roaster of roasters) {
        let currentState = roaster.state;
        // If we have not collected this state, add the {name, roasters} construct under it, and the current roaster
        if (roastersByState[currentState] === undefined) {
          roastersByState[currentState] = {name: currentState, roasters: [roaster]};
        } 
        // Otherwise, add the roasters to the state's list directly
        else {
          roastersByState[currentState].roasters = [...roastersByState[currentState].roasters, roaster]
        }
      }
      // For some reason, returning the object did not work when I tried it
      // It might be that the before callback only accepts an array in the return?
      // Not sure, I might have missed something
      return Object.values(roastersByState);
    },
    // Keep one item (from the transformed collection, see below) per page
    size: 1,
    resolve: "values",
    // A more appropriate name for the data
    alias: "stateWithRoasters"
  },
  // The output path for each item of this pagination
  permalink: "/state/{{stateWithRoasters.name | slug }}/index.html"
}
---

{% extends "layouts/default.njk" %}

{% block content %}
<ol>
{%- for roaster in stateWithRoasters.roasters %}
  <li>{{ roaster.name }}</li>
{% endfor -%}
</ol>
{% endblock %}

I put this under pages/state/index.njk.
It outputs files under /state/alabama/index.html