Changing fields based on database values

Question

Hi all,
I have one form and two drop -down fields. The fields are Call Type and Sub Call Type and are on the SAME form. I pull data from the Call Type from the database. When the user selects a particular Call Type, I need to go back to the database and pull in values associated with that particular Call Type.
This is the method, that I am using:-
1) I first populate the Call Type drop down field by using a Server Side Method to fill in values for the Call Type and calling the database.
2) I then call a method called as PopulateSubCallType by using the property On Change Invoke for the Call Type field.
In this method I again call the database and based on the Call Type selected by the user, I pull in the associated Sub Call Types and store them in an array.
3) I also call the same array to populate the Sub Call Types based on Call Types. But the drop down field for Sub Call Type is not auto-populated based on the values from the array. The array values although pulled up from the database are not shown on the form.
Can you tell me a way to auto-populate the Sub Call Type from the database based on the Call Type selected by the user but on the SAME form.
I AM NOT USING JSP's but ONLY ALBPM 6.0 PRESENTATIONS.

Answer 1

refreshValidValues("someAttribute") is a method that comes with BPM Object presentations.
This one line in this method will work because it causes the attribute (child in this case) to automatically invoke the method you created for retrieving the valid values of the children of the parent.
Your server side method that dynamically returns valid values of the children based on the parent selected should be looking something like this:
for each ...
select * from child
where parentOfChild = parentAttribute
In this example the name of your parent attribute is "parentAttribute" column in the child database table that contains the parent's id is "parentOfChild".
This causes the list of children to auto populate in the child combo dropdown automatically.
To summarize - at runtime here is what happens:
a) since the parent has a dynamic method that populates its valid values, as the presentation initializes the SQL for the valid values of the parent is run.
b) the parent's combo dropdown is populated with a list of valid values of the parent
c) the end user selects one of the parent's names from the combo dropdown
d) this causes the method to fire that has only one line. This one line has the text "refreshValidValues("nameOfTheChildAttributeGoesHere")
e) since the child has a dynamic method that populates its valid values, when the previous step caused this child attribute to refresh its valid values, the SQL in the method that dynamically retrieves the valid values of the child is run.
f) the end user clicks the combo dropdown on the child's attribute and sees that the child valid values (based on the parent that was just selected) now appear.
Dan