feat: added multi-select for input parameters. Fixes #12017

docs/executor_swagger.md

@@ -2867,6 +2867,7 @@ More info: http://kubernetes.io/docs/user-guide/identifiers#names |  |
 | enum | [][AnyString](#any-string)| `[]AnyString` |  | | Enum holds a list of string values to choose from, for the actual value of the parameter |  |
 | globalName | string| `string` |  | | GlobalName exports an output parameter to the global scope, making it available as
 '{{workflow.outputs.parameters.XXXX}} and in workflow.status.outputs.parameters |  |
+| multi | boolean| `bool` |  | | Multi is a boolean which decides whether value should be interpreted as a multi-select, or as a single-select |  |
 | name | string| `string` |  | | Name is the parameter name |  |
 | value | [AnyString](#any-string)| `AnyString` |  | |  |  |
 | valueFrom | [ValueFrom](#value-from)| `ValueFrom` |  | |  |  |

docs/fields.md

@@ -2249,6 +2249,7 @@ Parameter indicate a passed string parameter to a service template with an optio
 |`description`|`string`|Description is the parameter description|
 |`enum`|`Array< string >`|Enum holds a list of string values to choose from, for the actual value of the parameter|
 |`globalName`|`string`|GlobalName exports an output parameter to the global scope, making it available as '{{io.argoproj.workflow.v1alpha1.outputs.parameters.XXXX}} and in workflow.status.outputs.parameters|
+|`multi`|`boolean`|Multi is a boolean which decides whether value should be interpreted as a multi-select, or as a single-select|
 |`name`|`string`|Name is the parameter name|
 |`value`|`string`|Value is the literal value to use for the parameter. If specified in the context of an input parameter, the value takes precedence over any passed values|
 |`valueFrom`|[`ValueFrom`](#valuefrom)|ValueFrom is the source for the output parameter's value|

docs/workflow-templates.md

@@ -373,9 +373,46 @@ spec:
       - name: message
         value: one
         enum:
-          -   one
-          -   two
-          -   three
+          - one
+          - two
+          - three
+  templates:
+    - name: argosay
+      inputs:
+        parameters:
+          - name: message
+            value: '{{workflow.parameters.message}}'
+      container:
+        name: main
+        image: 'argoproj/argosay:v2'
+        command:
+          - /argosay
+        args:
+          - echo
+          - '{{inputs.parameters.message}}'
+```
+
+In case the user would like to use a multi-select dropdown, the same setup as above remains, you just need to:
+
+- Add a field named `multi: true`
+- Using the value still as a string, but with a `,` delimiter with the options you choose, without spaces before or after the delimiter.
+
+```yaml
+apiVersion: argoproj.io/v1alpha1
+kind: WorkflowTemplate
+metadata:
+  name: workflow-template-with-enum-values
+spec:
+  entrypoint: argosay
+  arguments:
+    parameters:
+      - name: message
+        multi: true
+        value: one,two
+        enum:
+          - one
+          - two
+          - three
   templates:
     - name: argosay
       inputs: