How can I get parameters in twig?

Question

I wrote a PHP script to deploy data to live-cdn and included a "deploy" button on the dashboard. the script returns ?success=true, and i need to show div element with "Congratulations"

i tried this with no success:

{% if app.request.query.get('success') %}
  <div>
    Glückwunsch! Deployment läuft.
  </div>
{% endif %}

Answer 1

Use:

{% if craft.request.getQueryString('success') %}

https://craftcms.com/docs/templating/craft.request#getQueryString

Answer 2

Actually, reading from the Craft 2 docs it's:

craft.request.getQueryString()      // returns the whole query string
craft.request.getQuery('success')   // returns only the value of 'success'

Answer 3

As @kr37 pointed out in the comments to another answer, the method for Craft 3, and now 4, is craft.app.request.getQueryParam()

{# get $_GET['foo'], if it exists #}
{% set foo = craft.app.request.getQueryParam('foo') %}

{# get $_GET['foo']['bar'], if it exists #}
{% set bar = craft.app.request.getQueryParam('foo.bar') %}