Controlling instances in dynamic forms with a strange twist.

Question

Hello,<br /><br />Is there a way to program a numeric text field that controls the number of instances of a subform? For example, I would like to have a nested subform appear twice in the form if the user enters 2 in the numeric field. But more importantly, I would like to see its corresponding XML output appear like the following:<br /><br /><SUBUNIT_1><br />   <LENGTH></LENGTH><br />   <SEQUENCE><br />       ELEESGGGLVQPGGRQSPEKGLETHYAE<br />   </SEQUENCE><br />   <N_TERMINAL>Yes</N_TERMINAL><br />   <C_TERMINAL></C_TERMINAL><br /></SUBUNIT_1><br /><br /><SUBUNIT_2><br />   <LENGTH></LENGTH><br />   <SEQUENCE><br />       ELEESGGGLVQPGGRQSPEKGLETHYAE<br />   </SEQUENCE><br />   <N_TERMINAL>No</N_TERMINAL><br />   <C_TERMINAL></C_TERMINAL><br /></SUBUNIT_2><br /><br />If you pay close attention to the above code, you will see that I want the parent tag's ending digit incremented each time the subform is repeated.  <SUBUNIT_1> <SUBUNIT_2> <SUBUNIT_3> ect  . . .<br /><br />That is the twist! Is this programmatically possible?<br /><br />Regards.<br /><br />Harold

Answer 1

Harold,<br /><br />The code to create a specific number of instances is as follows:<br />JavaScript <br />Subform1.setInstances(2); <br />or<br />Subform.instanceManager.setInstances(2); <br />FormCalc <br />comments.setInstances(2); // Subform name = comments <br /><br />If you are looking for documentation watch out: it's listed as setInstance rather than setInstances!<br /><br />If your form is associated to a specific data structure via a Data Connection (typically an XSD) then a subform repeats based on a repeating element in  the XML or, if the subform instances are instatiated programatically as yours would need to be, then the generated data will have repeated elements.<br /><br />If, however, your form fields are not bound to any specific data structure then you've got your work cut out but I think you could achieve the twist you require. I think you will have to write some code to build the XML structure that you require. Your code can refer to the fields on the form to extract the data and build the <dataset>. You'll need to know about scripting DOM (Document Object Model) to achieve this.<br /><br />A third option, if you are using Forms Server or LC Workflow to process the form submission, is to write Java code that processes the submitted data and transforms it to the required strucure.<br /><br />Or a fourth that has just crossed my mind is to associate an XSLT stylesheet to the form to process the outgoing doing. I'm afraid I don't really know any more about that to be 100% sure that would satisfy your requirement.<br /><br />Hope these ideas help.<br /><br />Neil