Use function provided by plugin only if plugin is installed and enabled I want to use asset rev in my template, but only if plugin is installed and enabled:

    {% if craft.app.plugins.getPlugin('assetrev') is not null and craft.app.plugins.getPlugin('assetrev').isInstalled %}
        {% set fileName = rev(file) %}
    {% else %}
        {% set fileName = file %}
    {% endif %}


Hovewer when i disable plugin, mere existence of rev function in my template, still causes error.
you can check if the plugin is installed and enabled with:

{% if craft.app.plugins.isPluginEnabled('assetrev') %}
  {% set fileName = rev(file) %}
{% else %}
  {% set fileName = file %}
{% endif %}


you won't need the extra check craft.app.plugins.isPluginInstalled('assetrev') then.

isPluginEnabled():


  Returns whether a given plugin is installed and enabled.