What is the best way to determine if a dictionary contains a key in a DataFlow?

[squirlemaster42]

I am trying to determine if the Form Data output of the Web Receive module contains a certain key so that I know if I can access it or now. What is the best way currently to do this?

[eschenfeldt]

Similar to #40 , I think these are the two "best" options I'm aware of:

• DataBinder Eval with continue on error
• Named Dictionary Splitter and loop over all of the keys