I am sure most of us have had to pass parameters from form A to protocol B. We could use the "additional parameters to pass" parameter on the input form component or the "pass hidden parameters" component. Both of them used to work well for me.

Recently I noticed a difference in behaviour though:

When you have a default value set up in your parameter on form A (say a default file name in a text box etc...) and try to pass the value to protocol B using either of the two techniques, here' what I observed.

Both the methods pass an array to the protocolB .

However, the input form passes an array that looks like

",a" (appends the selected value/input to an array with an empty first value)

and the hidden data form passes an array the looks like

"a," (prepends the selected value/input to an array with an empty last value)

Therefore, the way one would process these in protocolB has to be carefully designed.

Just thought this might be useful!

Arvind