Array or JSON Object Process Variable

Flowable Engine
1

It seems the engine is not allowing me to save arrays and json objects to the process using execution.setVariable

Doing the following results in an error:

var t = [5, 6];
execution.setVariable(“values”, t);

2

Hi,

the exception says:

org.flowable.engine.common.api.FlowableException: couldn't find a variable type that is able to serialize [object Array]
	at org.flowable.engine.impl.variable.DefaultVariableTypes.findVariableType(DefaultVariableTypes.java:62)
	at org.flowable.engine.impl.persistence.entity.VariableScopeImpl.createVariableInstance(VariableScopeImpl.java:863)
	at org.flowable.engine.impl.persistence.entity.ExecutionEntityImpl.createVariableInstance(ExecutionEntityImpl.java:531)
	at org.flowable.engine.impl.persistence.entity.VariableScopeImpl.createVariableLocal(VariableScopeImpl.java:784)
	at org.flowable.engine.impl.persistence.entity.VariableScopeImpl.setVariable(VariableScopeImpl.java:662)
	at org.flowable.engine.impl.persistence.entity.VariableScopeImpl.setVariable(VariableScopeImpl.java:654)

You can easily add new type support in ProcessEngineConfiguration.
See org.flowable.engine.impl.cfg.ProcessEngineConfigurationImpl#initVariableTypes

public void initVariableTypes() {
    if (variableTypes == null) {
        variableTypes = new DefaultVariableTypes();
        if (customPreVariableTypes != null) {
            for (VariableType customVariableType : customPreVariableTypes) {
                variableTypes.addType(customVariableType);
            }
        }
        variableTypes.addType(new NullType());
        variableTypes.addType(new StringType(getMaxLengthString()));
        variableTypes.addType(new LongStringType(getMaxLengthString() + 1));

The example in the jUnit test is org.flowable.examples.variables.VariablesTest#testBasicVariableOperations

Regards
Martin

3

Hi Martin,

What is the method for doing this in flowable 6. ProcessEngineConfiguration does not have any methods for setting variable types.

Regards

Brian

4

Got it to work by injecting my type into config. See below. Is there a reason that there is no method on the ProcessEngineConfiguration interface. Not sure why I needed to use the Impl class:

ProcessEngineConfiguration cfg = new StandaloneProcessEngineConfiguration()
.setJdbcUrl(“jdbc:h2:mem:flowable;DB_CLOSE_DELAY=-1”)
.setJdbcUsername(“sa”)
.setJdbcPassword("")
.setJdbcDriver(“org.h2.Driver”)
.setDatabaseSchemaUpdate(ProcessEngineConfiguration.DB_SCHEMA_UPDATE_TRUE);

	//cfg.getDef	
		
  ProcessEngineConfigurationImpl processEngineConfig = (ProcessEngineConfigurationImpl)cfg;
  processEngineConfig.initVariableTypes();
  processEngineConfig.getVariableTypes().addType(new CustomObjectType("camelbody", CamelBody.class));

  ProcessEngine processEngine =  processEngineConfig.buildProcessEngine();
5

@boneill you If you use an instance of the StandaloneProcessEngineConfiguration then you would get access to it. On top of that I would advise against doing what you are doing? calling initVariableTypes and then adding to it.

Instead I would do:

ProcessEngineConfiguration cfg = new StandaloneProcessEngineConfiguration()
.setJdbcUrl(“jdbc:h2:mem:flowable;DB_CLOSE_DELAY=-1”)
.setJdbcUsername(“sa”)
.setJdbcPassword("")
.setJdbcDriver(“org.h2.Driver”)
.setDatabaseSchemaUpdate(ProcessEngineConfiguration.DB_SCHEMA_UPDATE_TRUE)
.setCustomPostVariableTypes(Arrays.asList(new CustomObjectType("camelbody", CamelBody.class)));

ProcessEngine processEngine =  processEngineConfig.buildProcessEngine();

Cheers,
Filip