Categories Fields

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Categories are being phased out in favor of Structure sections. The corresponding entries field has a maintain hierarchy setting that mimics categories fields.

Read more about this transition (opens new window) on our blog.

Categories fields allow you to relate categories to other elements. It is one of Craft’s relational custom fields.

# Settings

Categories fields have the following settings:

  • Source — Which category group (or other category index source) the field should be able to relate categories from.

  • Maintain Hierarchy — Should the selected categories’ order and hierarchy be preserved?

    When enabled, the following options become available:

    • Branch Limit — How many distinct “branches” of the category tree can be selected?

    When disabled, these options are available:

    • Min Relations — The minimum number of categories that must be selected when the field is marked as “required” in a field layout. (Default is no minimum.)
    • Max Relations — The maximum number of categories that can be selected. (Default is no maximum.)
  • Selection Label — The label that should be used on the field’s selection button.

# Multi-Site Settings

On multi-site installs, the following settings will also be available (under “Advanced”):

  • Relate categories from a specific site? – Whether to only allow relations to categories from a specific site.

    If enabled, a new setting will appear where you can choose which site.

    If disabled, related categories will always be pulled from the current site.

  • Manage relations on a per-site basis – Whether each site should get its own set of related categories.

# The Field

Categories fields list all the currently-related categories with a button to select new ones.

Choosing Add a category will bring up a modal window where you can find and select additional categories. You can create new categories from this modal as well, by choosing New category.

When you select a nested category, all the ancestors leading up to that category will also automatically be related. Likewise, when you remove a category from within the main field input, any of its descendants will also be removed.

# Inline Category Editing

Double-click on a related category to edit it in a slideout.

# Development

# Querying Elements with Categories Fields

When querying for elements that have a Categories field, you can filter the results based on the Categories field data using a query param named after your field’s handle.

Possible values include:

Value Fetches elements…
':empty:' that don’t have any related categories.
':notempty:' that have at least one related category.
100 that are related to the category with an ID of 100.
[100, 200] that are related to a category with an ID of 100 or 200.
[':empty:', 100, 200] with no related categories, or are related to a category with an ID of 100 or 200.
['and', 100, 200] that are related to the categories with IDs of 100 and 200.
a Category (opens new window) object that are related to the category.
a CategoryQuery (opens new window) object that are related to any of the resulting categories.
{# Fetch entries with a related category #}
{% set entries = craft.entries()
  .myFieldHandle(':notempty:')
  .all() %}

# Working with Categories Field Data

If you have an element with a Categories field in your template, you can access its related categories using your Categories field’s handle:

{% set query = entry.myFieldHandle %}

That will give you a category query, prepped to output all the related categories for the given field.

To loop through all the related categories as a flat list, call all() (opens new window) and then loop over the results:

{% set relatedCategories = entry.myFieldHandle.all() %}
{% if relatedCategories|length %}
  <ul>
    {% for rel in relatedCategories %}
      <li><a href="{{ rel.url }}">{{ rel.title }}</a></li>
    {% endfor %}
  </ul>
{% endif %}

Or you can show them as a hierarchical list with the nav tag:

{% set relatedCategories = entry.myFieldHandle.all() %}
{% if relatedCategories|length %}
  <ul>
    {% nav rel in relatedCategories %}
      <li>
        <a href="{{ rel.url }}">{{ rel.title }}</a>
        {% ifchildren %}
          <ul>
            {% children %}
          </ul>
        {% endifchildren %}
      </li>
    {% endnav %}
  </ul>
{% endif %}

If you only want the first related category, call one() (opens new window) instead and make sure it returned something:

{% set rel = entry.myFieldHandle.one() %}
{% if rel %}
  <p><a href="{{ rel.url }}">{{ rel.title }}</a></p>
{% endif %}

If you need to check for related categories without fetching them, you can call exists() (opens new window):

{% if entry.myFieldHandle.exists() %}
  <p>There are related categories!</p>
{% endif %}

You can set parameters on the category query as well. For example, to only fetch the “leaves” (categories without any children), set the leaves param:

{% set relatedCategories = entry.myFieldHandle
  .leaves()
  .all() %}

In Craft 3, we recommended cloning these query objects using the clone keyword (opens new window) or clone() Twig function before applying params. This is no longer required in Craft 4, because a new copy of the query is returned each time you access the field property.

# Saving Categories Fields

If you have an element form, such as an entry form (opens new window), that needs to contain a Categories field, you will need to submit your field value as a list of category IDs.

For example, you could create a list of checkboxes for each of the possible relations:

{# Include a hidden input first so Craft knows to update the existing value
   if no checkboxes are checked. #}
{{ hiddenInput('fields[myFieldHandle]', '') }}

{# Get all of the possible category options #}
{% set possibleCategories = craft.categories()
  .group('food')
  .all() %}

{# Get the currently related category IDs #}
{% set relatedCategoryIds = entry is defined
  ? entry.myFieldHandle.ids()
  : [] %}

<ul>
  {% nav possibleCategory in possibleCategories %}
    <li>
      <label>
        {{ input(
          'checkbox',
          'fields[myFieldHandle][]',
          possibleCategory.id,
          { checked: possibleCategory.id in relatedCategoryIds }
        ) }}
        {{ possibleCategory.title }}
      </label>
      {% ifchildren %}
        <ul>
          {% children %}
        </ul>
      {% endifchildren %}
    </li>
  {% endnav %}
</ul>

Note that it’s not possible to customize the order that categories will be related in, and if a nested category is related, so will each of its ancestors.

# See Also