How do I get the current destination URL query parameter?

Question

Does anyone know to how to get the destination in a template file?

At the moment I an getting the destination parameters in a preprocess function.

// Get destination params.
$variables['destination_params'] = \Drupal::destination()->getAsArray();

The template file uses the following code.

<p>
You can try <a href="{{ path('user.login', {}, {'query': destination_params}) }}">logging in</a> to see if you have access.
</p>

Answer 1

You can use path() function with '<current>' pseudo URI to generate current page relative URL.

For example:

{# in hard-coded path (bad practice) #}
<a href="/user/login?destination={{ path('<current>') }}" class="btn btn-sm btn-primary icon-before"><i class="fad fa-sign-in"></i> Sign-In</a>

{# more proper twig-like way #}
<p>
You can try <a href="{{ path('user.login', {}, {'query': {'destination': path('<current>') }}) }}">logging in</a> to see if you have access.
</p>

More about Drupal's twig built-in functions here: https://www.drupal.org/docs/theming-drupal/twig-in-drupal/functions-in-twig-templates

Answer 2

Adding this here which expands on the answer given here by @MiSHuTka (that answer work perfectly for most scenarios with cache data)

Noting that both answers will not provide any extra query parameters in the destination query parameter. (if you wanted them to persist)

Sometimes you need to add the html link to an render array item instead of the template itself to get cache data to work correctly (I believe this has something to do with #theme_wrappers and #theme on the same render array?). So use '#type': 'inline_template' + verbatim tag to force string, so it be reparsed to bubble cache data.

{% set login_link %}
  {# verbatim used to force a string, so it can be reparsed as twig later on, keeping cache metadata in the correct context #}
  {% verbatim  %}
    <a href="{{ path('user.login', {}, {'query': {'destination': path('<current>')} }) }}">{{ 'Login'|t }}</a>
  {% endverbatim %}
{% endset %}

{% set extra_render = {'#type': 'inline_template', '#template': login_link} %}

Use like so:

{% extends "field.html.twig" %}
{% for key, item in items %}
    {# Add markup to the the render array - assume `extra_render` variable. #}
    {% set item_content = item.content|merge( {'extra_render': extra_render} ) %}
    {% set item = item|merge({'content': item_content }) %}
    {# Prepend to render array #}
    {% set items = {(key): item} + items %}
  {% endfor %}

Edit: I have noted that for some reason. If variable is printed via twig white space control {{- render_var -}} then the verbatim string is not rendered, just printed as is. (regular set/end set works fine but renders too early of course for caching) Solution: Use inline_template + #context: _context. E.g. {% set extra_render = {'#type': 'inline_template', '#template': mysetverbatimstring, '#context': _context }

For {{- render_var -}} - twig white space control @see https://www.drupal.org/docs/theming-drupal/twig-in-drupal/comparison-of-phptemplate-and-twig-theming-paradigms#whitespace

For _context @see https://twig.symfony.com/doc/2.x/templates.html#global-variables