#462 Make IterationParam in foreach state optional (#477)

* #462 Make IterationParam in foreach state optional

Signed-off-by: cb-manick <[email protected]>

* updated text on spec doc and added to roadmap

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

Co-authored-by: Tihomir Surdilovic <[email protected]>

Author: manick02

roadmap/README.md

@@ -23,8 +23,9 @@ _Status description:_
 | Status | Description | Comments |
 | --- | --- |  --- |
 | ✔️| Support custom function `type` definition | [spec doc](https://github.com/serverlessworkflow/specification/blob/main/specification.md)  |
-| ✔️| Workflow "name" no longer a required parameter | [spec doc](https://github.com/serverlessworkflow/specification/blob/main/specification.md)  |
-| ✔️| Workflow "start" no longer a required parameter| [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)  |
 | ✏️️| Support for async action invocation |   |
 | ✏️️| Start work on TCK  |   |
 | ✏️️| Add more samples  |   |

schema/workflow.json

@@ -1608,7 +1608,6 @@
           "name",
           "type",
           "inputCollection",
-          "iterationParam",
           "actions"
         ]
       },
@@ -1619,7 +1618,6 @@
               "name",
               "type",
               "inputCollection",
-              "iterationParam",
               "actions",
               "end"
             ]
@@ -1629,7 +1627,6 @@
               "name",
               "type",
               "inputCollection",
-              "iterationParam",
               "actions",
               "transition"
             ]

specification.md

@@ -2854,7 +2854,7 @@ The `timeouts` property can be used to define state specific timeout settings. I
 | type | State type | string | yes |
 | inputCollection | Workflow expression selecting an array element of the states data | string | yes |
 | outputCollection | Workflow expression specifying an array element of the states data to add the results of each iteration | string | no |
-| iterationParam | Name of the iteration parameter that can be referenced in actions/workflow. For each parallel iteration, this param should contain an unique element of the inputCollection array | string | yes |
+| iterationParam | Name of the iteration parameter that can be referenced in actions/workflow. For each parallel iteration, this param should contain an unique element of the inputCollection array | string | no |
 | batchSize | Specifies how many iterations may run in parallel at the same time. Used if `mode` property is set to `parallel` (default). If not specified, its value should be the size of the `inputCollection` | string or number | no |
 | mode | Specifies how iterations are to be performed (sequentially or in parallel). Default is `parallel` | string  | no |
 | [actions](#Action-Definition) | Actions to be executed for each of the elements of inputCollection | array | yes |
@@ -2926,8 +2926,8 @@ Each iteration of the ForEach state is by default executed in parallel by defaul
 However, executing iterations sequentially is also possible by setting the value of the `mode` property to
 `sequential`.
 
-The `mode` property defines if iterations should be done sequentially or in parallel. By default 
-(if `mode` is not specified) iterations should be done in parallel.
+The `mode` property defines if iterations should be done sequentially or in parallel. By default,
+if `mode` is not specified, iterations should be done in parallel.
 
 If the default `parallel` iteration mode is used, the `batchSize` property to the number of iterations (batch) 
 that can be executed at a time. To give an example, if the number of iterations is 55 and `batchSize`
@@ -2942,9 +2942,10 @@ an error. This error can be handled inside the states [`onErrors`](#Error-Defini
 The `outputCollection` property is a workflow expression which selects an array in the state data where the results
 of each iteration should be added to. If this array does not exist, it should be created.
 
-The `iterationParam` property defines the name of the iteration parameter passed to each parallel execution of the ForEach state.
-It should contain the unique element of the `inputCollection` array and passed as data input to the actions/workflow defined.
-`iterationParam` should be created for each iteration, so it can be referenced/used in defined actions / workflow data input.
+The `iterationParam` property defines the name of the iteration parameter passed to each iteration of the ForEach state.
+It should contain the unique element of the `inputCollection` array and made available to actions of the ForEach state.
+If `iterationParam` is not explicitly defined, runtimes should create one and populate it with the value of the unique 
+iteration parameter for each iteration of the ForEach state.
 
 The `actions` property defines actions to be executed in each state iteration.