在树枝模板中设置变量，然后将其与另一个变量一起使用

Question

I have the folowing long variable in Twig to read the src attribute of an image in RSS feed:

<img src="{{item.get_item_tags("http://www.w3.org/2005/Atom","link")[0]['child']['http://search.yahoo.com/mrss/']['content'][0]['child']['http://search.yahoo.com/mrss/']['thumbnail'][0]['child']['http://www.w3.org/2005/Atom']['img'][0]['attribs']['']['src']}}"/>

I want to make the code more cleaner and readable, so initially, I defined two variables to act as parameter of get_item_tags() and the other as a path for the array:

{% set param1 = 'http://www.w3.org/2005/Atom' %}
{% set arrayPath = '[0]['child']['http://search.yahoo.com/mrss/']['content'][0]['child']['http://search.yahoo.com/mrss/']['thumbnail'][0]['child']['http://www.w3.org/2005/Atom']['img'][0]['attribs']['']['src']' %}

What I want to get, but it generate error, is:

<img src="{{item.get_item_tags({{param1}}, "link"){{arrayPath}}}}" />

I don't use symfony and Twig version is 1.16.0

Answer 1

When you set a variable in twig and want to use it inside another function either in {{ }} or {% %} you do not need to use {{ }} again for the set variable.
Furthermore, you cannot set a variable as index of another variable then concat them; so you need to change it to:

{% set param1 = 'http://www.w3.org/2005/Atom' %}
{% set output = item.get_item_tags(param1, "link") %}
{% set yk = 'http://search.yahoo.com/mrss/' %}
<img src="{{ output[0]['child'][(yk)]['content'][0]['child'][(yk)]['thumbnail'][0]['child']['http://www.w3.org/2005/Atom']['img'][0]['attribs']['']['src'] }}" />