Multiple Dependent Dropdowns

[asawyer13]

I have a UX component with 2 text boxes, and 4 dropdowns. It is not bound to a table.

Basically I need a way when any of the 6 items change in value, I need to be able to repopulate the 4 dropdowns. The dropdowns are going to be loaded from sql queries.

Is this possible? and if so, can someone explain to me how to do it?

Thanks in advance,
Alan

[lvasic]

Re: Multiple Dependent Dropdowns

You can use the on-change event for each text box and dropdown and re-set everything.

[Davidk]

Re: Multiple Dependent Dropdowns

Just confirming that you're using DropdownBox Controls... and not TextBox Control configured as Edit-Combo Lists.

How are you filtering the DropdownBox control SQL queries?

The DropdownBox control is nice... except it's kinda brain dead. There's no way to dynamically filter the dropdown through the builder... without using a Session variable. If you've using it for a website, all good. But session vars for Mobile are deadly.

And... there's no way to delay the population of the control. So... you end up with populating the full dropdownbox... and then re-calling Ajax callbacks to filter it.

You can use the .refreshDropdownBoxChoices() method to refresh and filter your 4 dropdown controls at the same time.

https://www.alphasoftware.com/docume...s%20Method.xml

[asawyer13]

Re: Multiple Dependent Dropdowns

Thanks everyone.

I am going to be using regular dropdownbox controls. It's kind of difficult to explain here what I'm wanting to do, but basically I will be using values from two text boxes and possibly other dropdowns to filter what's going to be in each dropdown. I also will need to position the selected item to the same item it was before I reloaded the dropdown. I will look at the link and see if I can figure it out. I'm just getting back into Alpha and web is still new to me, so I have a lot to learn. The good thing is one I understand how to do something I can use it over and over again.

[Davidk]

Re: Multiple Dependent Dropdowns

Doesn't sound too involved. But the Control to be used is important to know. Either a DropdownBox Control or a TextBox Control configured as a Lookup.

[asawyer13]

Re: Multiple Dependent Dropdowns

I believe I will use the dropdownbox unless there is a reason to do something else.

[Davidk]

Re: Multiple Dependent Dropdowns

Since you are using the DropdownBox control then you're forced into the use of Session variables. I've asked for years that this control be expanded into the current world, but no go. This control should have a choice of UX Argument, UX field, State variable, or Session variable... not just the extremely limiting Session variable.

Because you're working with Web and not Mobile then session variables will work... but it will cost you 2 Ajax Callbacks.

The onChange event of your controls would make an Ajax Callback to set a session variable based on your Textbox Controls. This Callback would return a refresh of the DropdownBox Controls.

For example, a Dropdownbox control might have a SQL Statement which includes a WHERE clause...

WHERE BILL_CITY = session.currCity

In a Textbox control, onChange event, in Text mode... you'd have...

{dialog.Object}.ajaxCallback('','','refreshDropdownBoxes','');

This calls an XBasic function named "refreshDropdownBoxes".

The code for ""refreshDropdownBoxes" would be...

function refreshDropdownBoxes as c (e as p)

	session.currCity = e.dataSubmitted.City
	refreshDropdownBoxes = "{dialog.Object}.refreshDropdownBoxChoices('drop1');"	
	
end function

This code would set session.currCity to the value of your "City" Textbox control... and then send back a refresh for your DropdownBox control.

I find this costly... because you need an Ajax Callback to reset your session var... and another Ajax Callback for the DropdownBox control to go get it's data. However, that's the way it is in Alpha.

[asawyer13]

Re: Multiple Dependent Dropdowns

DavidK, Thanks, I will try some tests and see if I can make this work.