REST batch process instance migrate with variables

Flowable Engine
1

Hi

We are migrating all process instances of a process definition by using the process definition migrate REST call. However, we would also like to update / edit / add / remove some variables of said instances.
We found the following POST body as a solution:

{
	"toProcessDefinitionId": "process:2:id",
	"activityMappings": [
		{
			"fromActivityId": "sid-1",
			"toActivityId": "sid-2"
		}
	],
  "processInstanceVariables":
	{
			"name" : "value"
	}
}

Does anybody know a way if it is possible to conditionally edit these variables, to see which value they already have in a certain activity of a running process before we would change them with the migration?
This is so that new process definitions don’t have to take into account that some values could be different from a previous process definition.

I find almost no documentation about these migration REST calls and their response are pretty empty when succeeded.

Thanks in advance

2

Hi rubends,

org.flowable.engine.migration.ProcessInstanceMigrationDocumentConverter#convertFromJson converts the json from the request to ProcessInstanceMigrationDocument you can add any pre/post upgradeScripts to your migration doc.
example:

...
"preUpgradeScript": {
    "language": "groovy",
    "script": "1+1"
  },
  "postUpgradeScript": {
    "language": "groovy",
    "script": "2+2"
  },
...

change variable type:

        processMigrationService.createProcessInstanceMigrationBuilder().preUpgradeScript(new Script("groovy",
                "import com.fasterxml.jackson.databind.ObjectMapper\n"
                        + "import com.fasterxml.jackson.databind.node.ArrayNode\n"
                        + "import org.flowable.engine.impl.context.Context\n"
                        + "\n"
                        + "List<String> list  = execution.getVariable('listVariable')\n"
                        + "\n"
                        + "ObjectMapper mapper = Context.getProcessEngineConfiguration().getObjectMapper()\n"
                        + "\n"
                        + "ArrayNode jsonArray = mapper.createArrayNode()\n"
                        + "list.each {jsonArray.add(it)}\n"
                        + "\n"
                        + "execution.setVariable(\"listVariable\", jsonArray)"))
                .migrateToProcessDefinition(targetProcessDefinition.getId())
                .migrate(processInstanceToMigrate.getId());

Regards
Martin