从Twig中的元素列表中查找元素（带条件）

Question

我想知道是否有可能（在Twig中）从元素列表中找到（例如书籍实例之类的）一本满足特定条件的特定书籍（例如，如前一卷那样具有特定的其他书籍） 。 PS：换句话说，是否可以查询Twig中的列表？ 谢谢！

Answer 1

您可以遍历您的图书并找到您正在寻找的图书：

{# Look for a book with previous book = 9 #}
{% set previousBook = 9 %}
{# Define the books array #}
{% set books = {
    1: {'title': 'A', 'previous': [7, 8]},
    2: {'title': 'B', 'previous': [9, 10]}
} %}

{# By default there is no result #}
{% set foundBook = null%}

{# Loop through books #}
{% for bookId, book in books %}
    {# Apply the test #}
    {% if previousBook in book.previous %}
        {# The book has been found, store it #}
        {% set foundBook = book %}
    {% endif %}
{% endfor %}

{# If a book has been found, display it #}
{% if foundBook is not null %}
    I found the "{{ foundBook.title }}" book which has previous book
        "{{ previousBook }}".
{% endif %}

但是通过在Controller中使用这个逻辑，你很可能更容易做同样的事情。