Anyone knows how to concatenate strings in twig? I want to do something like:
{{ concat('http://', app.request.host) }}
This should work fine:
{{ 'http://' ~ app.request.host }}
To add a filter - like 'trans' - in the same tag use
{{ ('http://' ~ app.request.host) | trans }}
As Adam Elsodaney points out, you can also use string interpolation, this does require double quoted strings:
{{ "http://#{app.request.host}" }}
The operator you are looking for is Tilde (~), like Alessandro said, and here it is in the documentation:
~: Converts all operands into strings and concatenates them. {{ "Hello " ~ name ~ "!" }} would return (assuming name is 'John') Hello John!. – http://twig.sensiolabs.org/doc/templates.html#other-operators
And here is an example somewhere else in the docs:
{% set greeting = 'Hello' %}
{% set name = 'Fabien' %}
{{ greeting ~ name|lower }} {# Hello fabien #}
{# use parenthesis to change precedence #}
{{ (greeting ~ name)|lower }} {# hello fabien #}
You can use ~
like {{ foo ~ 'inline string' ~ bar.fieldName }}
But you can also create your own concat
function to use it like in your question:{{ concat('http://', app.request.host) }}
:
In src/AppBundle/Twig/AppExtension.php
<?php
namespace AppBundle\Twig;
class AppExtension extends \Twig_Extension
{
/**
* {@inheritdoc}
*/
public function getFunctions()
{
return [
new \Twig_SimpleFunction('concat', [$this, 'concat'], ['is_safe' => ['html']]),
];
}
public function concat()
{
return implode('', func_get_args())
}
/**
* {@inheritdoc}
*/
public function getName()
{
return 'app_extension';
}
}
In app/config/services.yml
:
services:
app.twig_extension:
class: AppBundle\Twig\AppExtension
public: false
tags:
- { name: twig.extension }
format()
filterformat
filter which is more expressiveformat
filterformat
filter works like the sprintf
function in other programming languagesformat
filter may be less cumbersome than the ~ operator for more complex stringsexample00 string concat bare
{{ "%s%s%s!"|format('alpha','bravo','charlie') }} --- result -- alphabravocharlie!
example01 string concat with intervening text
{{ "The %s in %s falls mainly on the %s!"|format('alpha','bravo','charlie') }} --- result -- The alpha in bravo falls mainly on the charlie!
follows the same syntax as sprintf
in other languages
{{ "The %04d in %04d falls mainly on the %s!"|format(2,3,'tree') }} --- result -- The 0002 in 0003 falls mainly on the tree!
To mix strings, variables and translations I simply do the following:
{% set add_link = '
<a class="btn btn-xs btn-icon-only"
title="' ~ 'string.to_be_translated'|trans ~ '"
href="' ~ path('acme_myBundle_link',{'link':link.id}) ~ '">
</a>
' %}
Despite everything being mixed up, it works like a charm.