Add useResults and useData to action and event data filters (#499)

* Add useResults and useData to action and event data filters

Signed-off-by: Tihomir Surdilovic <[email protected]>

* fix spec doc value

Signed-off-by: Tihomir Surdilovic <[email protected]>

* added little more description

Signed-off-by: Tihomir Surdilovic <[email protected]>

* fix parenthesis

Signed-off-by: Tihomir Surdilovic <[email protected]>

* update to roadmap

Signed-off-by: Tihomir Surdilovic <[email protected]>

Author: tsurdilo

roadmap/README.md

@@ -24,8 +24,9 @@ _Status description:_
 | --- | --- |  --- |
 | ✔️| Support custom function `type` definition | [spec doc](https://github.com/serverlessworkflow/specification/blob/main/specification.md)  |
 | ✔️| Workflow "name" no longer a required property | [spec doc](https://github.com/serverlessworkflow/specification/blob/main/specification.md)  |
-| ✔️| Workflow "start" no longer a required property| [spec doc](https://github.com/serverlessworkflow/specification/blob/main/specification.md)  |
-| ✔️| ForEach state "iterationParam" no longer a required property| [spec doc](https://github.com/serverlessworkflow/specification/blob/main/specification.md)  |
+| ✔️| Workflow "start" no longer a required property | [spec doc](https://github.com/serverlessworkflow/specification/blob/main/specification.md)  |
+| ✔️| ForEach state "iterationParam" no longer a required property | [spec doc](https://github.com/serverlessworkflow/specification/blob/main/specification.md)  |
+| ✔️| Added "useData" for eventDataFilter, and "useResults" for actionDataFilter | [spec doc](https://github.com/serverlessworkflow/specification/blob/main/specification.md)  |
 | ✏️️| Support for async action invocation |   |
 | ✏️️| Add "completedBy" functionality |   |
 | ✏️️| Define workflow context |   |

schema/workflow.json

@@ -1911,9 +1911,14 @@
     "eventdatafilter": {
       "type": "object",
       "properties": {
+        "useData": {
+          "type": "boolean",
+          "description": "If set to false, event payload is not added/merged to state data. In this case 'data' and 'toStateData' should be ignored. Default is true.",
+          "default": true
+        },
         "data": {
           "type": "string",
-          "description": "Workflow expression that filters the received event/payload (default: '${ . }')"
+          "description": "Workflow expression that filters the received event payload (default: '${ . }')"
         },
         "toStateData": {
           "type": "string",
@@ -1930,6 +1935,11 @@
           "type": "string",
           "description": "Workflow expression that selects state data that the state action can use"
         },
+        "useResults": {
+          "type": "boolean",
+          "description": "If set to false, action data results are not added/merged to state data. In this case 'results' and 'toStateData' should be ignored. Default is true.",
+          "default": true
+        },
         "results": {
           "type": "string",
           "description": "Workflow expression that filters the actions data results"

specification.md

@@ -429,6 +429,7 @@ The second way would be to directly filter only the "veggie like" vegetables wit
 | Parameter | Description | Type | Required |
 | --- | --- | --- | --- |
 | fromStateData | Workflow expression that filters state data that can be used by the action | string | no |
+| useResults | If set to false, action data results are not added/merged to state data. In this case 'results' and 'toStateData' should be ignored. Default is true.  | boolean | no |
 | results | Workflow expression that filters the actions data results | string | no |
 | toStateData | Workflow expression that selects a state data element to which the action results should be added/merged into. If not specified denotes the top-level state data element | string | no |
 
@@ -555,10 +556,15 @@ into. With this, after our action executes the state data would be:
 }
 ```
 
+In the case action results should not be added/merged to state data, we can set the `useResults` property to `false`.
+In this case, the `results` and `toStateData` properties should be ignored, and nothing is added/merged to state data.
+If `useResults` is not specified (or it's value set to `true`), action results, if available, should be added/merged to state data.
+
 #### Event data filters
 
 | Parameter | Description | Type | Required |
 | --- | --- | --- | --- |
+| useData | If set to false, event payload is not added/merged to state data. In this case 'data' and 'toStateData' should be ignored. Default is true. | boolean | no |
 | data | Workflow expression that filters the event data (payload) | string | no |
 | toStateData | Workflow expression that selects a state data element to which the action results should be added/merged into. If not specified denotes the top-level state data element | string | no |
 
@@ -616,6 +622,11 @@ Note that the data input to the Event data filters depends on the `dataOnly` pro
 If this property is not defined (has default value of `true`), Event data filter expressions are evaluated against the event payload (the CloudEvents `data` attribute only). If it is set to
 `false`, the expressions should be evaluated against the entire CloudEvent (including its context attributes).
 
+In the case event data/payload should not be added/merged to state data, we can set the `useData` property to `false`.
+In this case, the `data` and `toStateData` properties should be ignored, and nothing is added/merged to state data.
+If `useData` is not specified (or it's value set to `true`), event payload, if available, should be added/merged to state data.
+
+
 #### Using multiple data filters
 
 As [Event states](#Event-State) can take advantage of all defined data filters. In the example below, we define