Adding action condition (#531)

* Adding action condition

Signed-off-by: Tihomir Surdilovic <tihomir@temporal.io>

* Update specification.md

Co-authored-by: Ricardo Zanini <1538000+ricardozanini@users.noreply.github.com>

Co-authored-by: Ricardo Zanini <1538000+ricardozanini@users.noreply.github.com>

Author: tsurdilo

roadmap/README.md

@@ -30,6 +30,7 @@ _Status description:_
 | ✔️| Added "resultEventTimeout" for action eventref | [spec doc](https://github.com/serverlessworkflow/specification/blob/main/specification.md)  |
 | ✔️| Added example for "continueAs" | [examples doc](https://github.com/serverlessworkflow/specification/blob/main/examples/README.md)  |
 | ✔️️| Support for async action invocation | [spec doc](https://github.com/serverlessworkflow/specification/blob/main/specification.md)  |
+| ✔️️| Support for action condition | [spec doc](https://github.com/serverlessworkflow/specification/blob/main/specification.md)  |
 | ✏️️| Add "completedBy" functionality |   |
 | ✏️️| Define workflow context |   |
 | ✏️️| Start work on TCK  |   |

schema/workflow.json

@@ -468,6 +468,11 @@
         "actionDataFilter": {
           "description": "Action data filter",
           "$ref": "#/definitions/actiondatafilter"
+        },
+        "condition": {
+          "description": "Expression, if defined, must evaluate to true for this action to be performed. If false, action is disregarded",
+          "type": "string",
+          "minLength": 1
         }
       },
       "additionalProperties": false,

specification.md

@@ -3732,6 +3732,7 @@ This is visualized in the diagram below:
 | retryableErrors | List of references to defined [workflow errors](#Defining Errors) for which the action should be retried. Used only when `autoRetries` is set to `false` | array | no |
 | [actionDataFilter](#Action-data-filters) | Action data filter definition | object | no |
 | sleep | Defines time periods workflow execution should sleep before / after function execution | object | no |
+| [condition](#Workflow-Expressions) | Expression, if defined, must evaluate to true for this action to be performed. If false, action is disregarded | boolean | no |
 
 <details><summary><strong>Click to view example definition</strong></summary>
 <p>
@@ -3810,6 +3811,10 @@ The `retryableErrors` property is a list that references one or more unique name
 This is the list of known errors for which the action should be retried for.
 It should be used only when the workflow top-level `autoRetries` property is set to `false`.
 
+The `condition` property is a [workflow expression](#Workflow-Expressions). If defined, it must evaluate to `true`
+for this action to be performed. If it evaluates to `false` the action is skipped. 
+If the `condition` property is not defined, the action is always performed.
+
 ##### Subflow Action
 
 Often you want to group your workflows into small logical units that solve a particular business problem and can be reused in