dear Readers,
After playing with the results widget, we found that query widget has a bunch of out of the box features. It took me some time to figure out that ALL was the equivalent of AND for all of the columns. In the Silverlight version of our app, (of course it is not out of the box - hand coded stuff) the end users had the ability to choose which filters they could operate on as shown below.
In the picture below, the all would skip the condition for that column through a stored procedure where parameter would @EAPParam = '' and inside the stored procedure the AND condition would be
AND (EAP = @EAPParam or @EAPParam = '') which would ensure that all EAP records are selected.

Now we are trying to implement the same app in WAB 1.3. I was able to open up fiddler and see the GET /ArcGIS/rest/services.... /0/query?f=...... if I choose any then it becomes an OR condition and if I chose ALL

then it is a set of AND conditions. Is there a way to 'intercept' the query and check for <NULL> or '' blank values to remove those from the query stack and send the appropriate values. I understand it cannot be done out of the box and that I have to find a js function in the wab black box.
any links pointers would be appreciated.
regards
ravi.