按类别过滤自定义帖子类型

Question

I'm trying to list all categories for a certain post type in a <select> element, using Timber and Twig. When the user then chooses a category, I only want the posts in that category to be displayed. How can I do that? All help is appreciated.

My controller:

<?php
/**
 * Template Name: QnA Page Template
 */

$context = Timber::get_context();
$post = new Timber\Post();

$args = array (
  'post_type' => 'qna',
  'posts_per_page' => -1
);

$context['post'] = $post;
$context['qna'] = Timber::get_posts($args);
Timber::render('templates/pages/template-qna.twig', $context);

My template, so far:

{% block content %}
    <select id="filter-by-category">
        <option></option>
        ...
    </select>
{% endblock %}

Answer 1

Try this:

<?php
/**
 * Template Name: QnA Page Template
 */
$context = Timber::get_context();

$context['post'] = new Timber\Post();
$context['qna']  = new Timber\PostQuery( [
    'post_type'      => 'qna',
    'posts_per_page' => -1
] );

$context['categories'] = Timber::get_terms( [
    'taxonomy' => 'category',
] );

Timber::render( 'templates/pages/template-qna.twig', $context );

To use your categories with a <select> tag, you can use the following:

{% block content %}
    <select id="filter-by-category">
        {% for category in categories %}
            <option value="{{ category.link }}">{{ category.title }}</option>
        {% endfor %}
    </select>
{% endblock %}

Of course you'd also need to watch for changes in your select with JavaScript and then redirect the user to the selected category archive.

Instead of using a select, it's way easier and probably more user-friendly to display all categories in an unordered list:

{% block content %}
    <ul>
        {% for category in categories %}
            <li><a href="{{ category.link }}">{{ category.title }}</a></li>
        {% endfor %}
    </ul>
{% endblock %}