[#arg-dropdowns]
= Input: Dropdowns

Predefined choices are normally the safest type of arguments, because users are limited to only enter values that you specify. 

[source,yaml]
----
actions:
  - title: Print a message
    icon: smile
    shell: echo "{{ message }}"
    arguments:
      - name: message
        description: The message you want to print out.
        choices:
          - title: Hello
            value: Hello there!

          - title: Goodbye
            value: Aww, goodbye. :-( 
----

Note that when predefined choices are used, the argument type is ignored.

This is what it looks like in the web interface;

image::args4.png[]

Then finally, when you execute this command, it would look something like this (remember that this is just a basic "echo" command). 

image::args-choices-exec.png[]

In the logs, you can then click on the log entry link to open the results;

image::args3.png[]

[#args-dropdown-entities]
== Using Entities in Dropdowns

Dropdowns can also be populated with a list of entities, like this;

[source,yaml]
.`config.yaml`
----
actions:
  - title: restart container
    shell: 'docker restart {{ containerToRestart }}'
    arguments:
      - name: containerToRestart
        entity: container
        title: 'Select Container'
        choices:
          - value: '{{ container.Names }}'
            title: '{{ container.Names }}'

entities:
  - file: entities/containers.json
    name: container
----

This is what it looks like in the web interface;

image::args-choices-entities.png[]

include::partial$args/reject-null.adoc[]

== Default values

Dropdown arguments can also have default values. This is done by adding a `default` key to the argument definition.

include::partial$config-start.adoc[]
----
actions:
  - title: "Print your favorite movie"
    shell: echo '{{ movie }} is amazing'
    arguments:
      - name: movie
        choices:
          - value: "Star Wars"
          - value: "Star Trek"
          - value: "The Matrix"
        default: "Star Trek"
----