Twig define dynamic generate variable

Question

I have field names:

• field_en_image
• field_sv_image

node_lang is set as a variable in the .theme file under _preprocess_node hook.

I want to print the field dynamically in the twig template file based on the current language.

{{ node.["field_"~node_lang~"image"]|view }}

but this seems to be not working.

Answer 1

Try the following

{% set field_name = "field_"~node_lang~"image" %}
{{ attribute(node,field_name) | view }} 

or

{% set field_name = "field_"~node_lang~"image" %}
{{ attribute(content,field_name) }} 

If you want to access a dynamic attribute of a variable, use the attribute function instead.

The attribute function is also useful when the attribute contains special characters (like - that would be interpreted as the minus operator):

{# equivalent to the non-working foo.data-foo #}
{{ attribute(foo, 'data-foo') }}

Answer 2

You should be using the _context variable instead, which represent the whole accessibles variables, you can find some informations about that variable under Macros documentation.

That snippet may help :

{% set language = 'fr' %}

{% set foobar = _context["field_" ~ language ~ "_foobar"] is defined ? _context["field_" ~ language ~ "_foobar"] : null %}

{{ foobar }}

I've wrote to you a little TwigFiddle, check it out :)