Building a simple search by multiple categories

Question

Is it possible to build the following/is it the right way in Craft. Been through the docs and searched but stuck.

I just need to build a form on one page with a dropdown select for 2 categories;

1. Location

2. Type

That then takes the user to the results page and returns entries where the location and type match.

Can someone be so kind as to provide a sample to get me going please?

Answer 1

Building the form is pretty straightforward, you get the categories from your "locations" and "types" category groups using craft.categories and loop them to build your select options. I choose to pass the category's slug as the value to submit and /results as the URL to submit to.

<form action="{{ url('results') }}" method="get">

    <label>Location</label>
    <select name="location">
        <option value="">all locations</option>
        {% set categories = craft.categories.group('locations') %}
        {% for category in categories %}
            <option value="{{ category.slug }}">{{ category.title }}</option>
        {% endfor %}
    </select>

    <label>Type</label>
    <select name="type">
        <option value="">all types</option>
        {% set categories = craft.categories.group('types') %}
        {% for category in categories %}
            <option value="{{ category.slug }}">{{ category.title }}</option>
        {% endfor %}
    </select>

    <button type="submit">Search</button>

</form>

Getting the entries that are related to categories from both, one or non of your category groups is a little bit more tricky. In case a category in both select options is selected, you need to use the following syntax for your relatedTo parameter (see Craft docs: "The relatedTo Param - Passing Multiple Relation Criteria"):

{% set cocktails = craft.entries.section('cocktails').relatedTo('and',
    { sourceElement: currentUser, field: 'favoriteCocktails' },
    { targetElement: gin, field: 'ingredients' }
) %}

I suggest to compose the value for the relatedTo parameter starting with an array ['and'] and then build upon this array, conditionally adding array elements (relation conditions) using the merge filter.

{# Get the search data #}
{% set locationParam = craft.request.getParam('location') %}
{% set typeParam = craft.request.getParam('type') %}

{# Compose the relation param #}
{% set relationParam = ['and'] %}

{% if locationParam %}
    {% set location = craft.categories.group('locations').slug(locationParam).first() %}
    {% set relationParam = relationParam|merge([{ targetElement: location }]) %}
{% endif %}

{% if typeParam %}
    {% set type = craft.categories.group('types').slug(typeParam).first() %}
    {% set relationParam = relationParam|merge([{ targetElement: type }]) %}
{% endif %}

{# Avoid passing an array with `['and']` only #}
{% if relationParam|length < 2 %}
    {% set relationParam = '' %}
{% endif %}

{# Find and list matching entries #}
{% set entries = craft.entries.relatedTo(relationParam) %}

{% if entries|length %}
    <ul>
        {% for entry in entries %}
            <li>{{ entry.title }}</li>
        {% endfor %}
    </ul>
{% else %}
    No entries found.
{% endif %}