nav[aria-label="Primary Navigation"] { padding: 0; & ul { list-style: none; width: 100%; display: flex; flex-direction: row; justify-content: start; align-items: start; gap: 30px; padding: 0; & li { margin: 0; } & ul li { list-style: none; } } }

As we transition to the new Hyland Community, some post links may be temporarily disrupted as we finalize redirects. We apologize for the inconvenience and are working to resolve this as quickly as possible. Details.

put 'null' to ProcessVariableMap

dognose

Hello,

for a save method of tasks i'm iterating over a list of available ProcessVariableKeys and using the
runtime service to flush variables without completing the task:

for (String varName : processVariableKeyList) {
   runtimeService.setVariable(businessProcess.getExecutionId(), varName, processVariables.get(varName));
}‍‍‍‍

This works perfectly fine for all variables.
However, if the user "removes" a entry from a Input, that is converted to a Double OR Date OR Long ….
The Converter returns "null" for that value, and therefore calls

processVariables.put("someDate",null);

calling
processVariables.get("someDate") afterwards will however return the PRIOR value of the date / double ….

Is this a known bug or expected behaviour and im doing something wrong?

processVariables.put("aDouble", 50.0); //works
processVariables.put("aDouble", null);
System.out.println(processVariables.get("aDouble")); //returns 50.0
‍‍‍‍‍

Working with activiti 5.10

Find more posts tagged with

Comments

frederikherema1

processVariables.put("someDate",null);
Is this activiti-code or your code?

dognose

Hello,

sry for posting "a little" late. Until now we bypassed the problem, but now we need to reconsider a solution to this problem.

Basically a user is able to "empty" a textfield from the UI-Point of view. Until now, we putted an empty string, which worked fine.
But for Data-Maintenance Reasons we need to store a null value instead of an empty string, whenever a user is going to empty the text-field.

Therefore we setup the following in the web.xml:

<br><context-param><br>&nbsp;&nbsp;&nbsp; <param-name><br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; javax.faces.INTERPRET_EMPTY_STRING_SUBMITTED_VALUES_AS_NULL<br>&nbsp;&nbsp;&nbsp; </param-name><br>&nbsp;&nbsp;&nbsp; <param-value>true</param-value><br>&nbsp; </context-param><br>

So, what has this to do with activiti?

Our form-elements are directly bounded to the entry in the ProcessvariableMap. Using a JSF 2.2 ViewScope, we perform some Ajax Operations and finally the submission of the form.

Every change to a field is stored properly, eccept when it resolves to `null`. We followed the Stacktrace down to the `ConversationScopeAssociation` of `DefaultContextAssociationManager` and found the following piece of code being executed:

DefaultContextAssociationManager

<br>@Override<br>&nbsp; public Object getVariable(String variableName) {<br>&nbsp;&nbsp;&nbsp; ExecutionEntity execution = getExecutionFromContext();<br>&nbsp;&nbsp;&nbsp; if(execution != null) {<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; return execution.getVariable(variableName);<br>&nbsp;&nbsp;&nbsp; } else {<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; return getScopedAssociation().getVariable(variableName);&nbsp; <br>&nbsp;&nbsp;&nbsp; }<br>&nbsp; }<br>

Here, execution will resolve to null, and the else-case will call the ConversationScopedAssociation:

<br> public <T> T getVariable(String variableName) {<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Object value = cachedVariables.get(variableName);<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; if(value == null) {<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; if(execution != null) {<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; value = runtimeService.getVariable(execution.getId(), variableName);<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; cachedVariables.put(variableName, value);<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; return (T) value;<br>&nbsp;&nbsp;&nbsp; }<br>

At this point, the cachedVariable-Map may contain our desired "key=null" - for loging purposes we are iterating over the map and getting the values again, to log the change: And this "removes" the null value from the cachedVariable map:

If the "value" is null - it's reloaded by the runtimeService. However at this point, we did not yet save the variables (flush). That means: the null is removed and the "old" value is restored inside the cachedVariable-Map before actually saving the changes.

I'm not sure wheter this is a bug or serves some purpose, but it looks pretty strange. It is essentially saying: "You are not allowing to have null values in the cachedVariable Map".

So, the current event-sequence is like:

ProcessVariableMap.put("someKey", null); //old value was "Hello World"
-> stored in CachedMap
-> calling ProcessVariableMap.get("someKey") // returns "Hello World", cause of the code outlined above.
-> calling businessProcess.complete() // now stores "Hello World" again, because the getter writes back to the cachedVariable map.

edit: Running on activiti 5.13