twig - Twig - Append string data to same variable

Question

How would you append more data to the same variable in Twig? For example, this is what I'm trying to do in Twig:

var data = "foo";
data += 'bar';

I have figured out that ~ appends strings together in Twig. When I try {% set data ~ 'foo' %} I get an error in Twig.

Answer 1

~操作员不执行赋值，这可能是错误的原因。

相反，您需要将附加的字符串分配回变量：

{% set data = data ~ 'foo' %}

另请参阅：如何在树枝中组合两个字符串？

Answer 2

Displaying dynamically in twig

{% for Resp in test.TestRespuestasA %}        
    {% set name = "preg_A_" ~ Resp.id %}
    {% set name_aux = "preg_A_comentario" ~ Resp.id %}
    <li>{{ form_row(attribute(form, name)) }}</li>
{% endfor %}

Answer 3

您还可以|append在 Twig 实例中定义一个自定义过滤器，如 Liquid 的过滤器，它执行相同的操作。

$loader = new Twig_Loader_Filesystem('./path/to/views/dir');
$twig = new Twig_Environment($loader);

...
...

$twig->addFilter(new Twig_SimpleFilter('append', function($val, $append) {
    return $val . $append;
}));

产生以下标记：

{% set pants = 'I\'m wearing stretchy pants!' %}
{% set part2 = ' and they\'re friggin\' comfy!' %}
{% set pants = pants|append(part2) %}

{{ pants }}

{# result: I'm wearing stretchy pants! and they're friggin' comfy! #}

恕我直言，我发现上面的示例比~组合器更直观，特别是在处理共享代码库时，语法新手可能会有点混淆。