This article was created in response to a support issue logged with K2. The content may include typographical errors and may be revised at any time without notice This article is not considered official documentation for K2 software and is provided “as is” with no warranties.

Issue

There is a list box that is bounded to a SMO. This list box is working as expected until the SMO does not return any value. When the SMO does not return any value, the expectation is that the list box will be empty, however it keeps the last known value. ie. it never gets cleared when there are no value in SMO. 

The issue encountered is similar to the following post: http://community.k2.com/t5/K2-blackpearl/How-to-Clear-a-List-Box-Control/ta-p/83908

Symptoms

We have a list box control that is bounded to a SmartObject.

This list box is working as expected until the SmartObject does not return any value.

When the SmartObject does not return any value, the expectation is that the list box will be empty, however it keeps the last known value. ie. it never gets cleared when there are no value in the SmartObject.

Troubleshooting Steps

To resolve this please complete the following Workaround:

1) Create an empty entry
2) Filter this entry on the Input mappings of the View initialize
3) Call two rules to populate the controls:

1) Show blank entry
2) Filter on input mapping (if input mapping is empty then the blank entry is shown).