input and output of a 'user input task'

Question

When the same process variable is updated by both the input and output of a 'user input task' what will be the result? From what I have tested, the input takes precedence. As implemented in the attached photo, the initialization set in the output (setting to NULL) does not execute.

Sri Ram Kaja · Accepted Answer

Hi Meme02 , 
 As far I know, The execution order will be 
 1) Value in input 
 2) outputs 
 3) Save into in inputs 
 So first the value are saved in activity class parameters and then outputs are executed and in the save into fields are executed. 
 
 In your example, whatever the value in form is saved into ac!errMsg first, then output is executed i.e, null is saved into pv!errMsg and then again ac!errMsg is saved in pv!errMsg

Shubham Aware · Answer

Meme02 
 For a user input task, the value you enter takes priority over any value set in the output. Your test confirms this - the input sets "errMsg" and the attempt to clear it in the output is ignored.

Mike Schmitt · Answer

The real answer to this is, of course, that conflicts like this should be avoided as much as possible (and luckily it's possible to avoid it at approaching 100% if design is done carefully), because one can never be sure what the order of precedence will actually be without either testing it or asking around (and i'm not completely convinced it is guaranteed to happen in a particular order either).

input and output of a 'user input task'

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