Show all items in cascading lists

[PhilM1965]

Hi All

I have two cascading lists that work just fine. I would like the child list to show all items in the list when there are no items selected in the parent list. Currently, no items are shown until an option in the parent list is selected.

I have a button which allows me to deselect the list using

var lObj = {dialog.object}.getControl('list2');
lObj._deselectAll();

(btw ... list1 is the child list, list2 is the parent list)

I would like to be able to click the button and effectively set the list to the same filter as the parent list, but omitting the argument from the filter.

Eg ... filter for list might be, when an item is selected :

WHERE StartDate >= getdate() AND EndDate <= getdate() AND Category = :aCategory (this works fine in the cascading list)

What I would like to happen when the button is clicked is for the parent list to have it's options deselected and the filter to now be

WHERE StartDate >= getdate() AND EndDate <= getdate()

I would prefer to have this as being a 'feature' of the parent list, rather than a function of the button, so that the child list displays all the records ignoring the argument, i.e. once the button sets the parent list choices to be deselected, then that should trigger the second WHERE clause above, and also that the second WHERE clause is the one used on entering the dialog (I have 'Allow Null selection' checked in both lists).

Possible? Clear as mud?

TIA

Phil

[PhilM1965]

Re: Show all items in cascading lists

Ok, here is what I did ...

I changed the lists from being cascading lists to being independent lists.

I set the filter on the second list to show all items from the data I wanted ...

StartDate <= getdate()  AND  EndDate >= getdate()

so that all records in the list would be displayed upon entering the dialog.

I set an argument called aCategory in the 'parent' list to be the category field from that list ... Alpha returns that value when an item is clicked.

I then added a button with the following code in the 'On Click' ... essentially the same as the original SQL filter to reset the list to it's original state as it would be on entering the dialog (List1 is the 'child' list). This button is called 'All Categories'. The second parameter is the list I wish to filter (List1). The third parameter is the sort field, and the final parameter is left blank as I am not using parameters.

{dialog.object}._filterList('LIST1','StartDate <= getdate() AND EndDate >= getdate()','StartDate','');

In the List Properties of List2 (the 'parent' list) in the OnClick section, I entered the following code

{dialog.object}._filterList('LIST1','StartDate <= getdate()  AND  EndDate >= getdate()  AND  Category = :aCategory','StartDate','');

This is essentially the same code as above but note we are also using the argument aCategory.

This allows me to show the records filtered between the dates I want, but just for the selected list.

Looking back, I could have probably just left it as a cascading list with the 'All Categories' button added as above, but hey ... it works now and if I need to add something else in, I already have a place to incorporate extra code

Well, I hope that helps someone in the future!

[Davidk]

Re: Show all items in cascading lists

Hey Phil,

I'm not so sure you could have left this as Cascading Lists. I was looking at this before you posted and, unless I'm mistaken, if you set a List as having a Parent List, then you must set a filter and part of that filter must be an argument pointing to the parent list. So you must have an opening filtered list. Also, I believe {dialog.object}._filterlist is an added filter in the case of Cascading Lists. Whatever filter you set is in addition to the cascading list filter. Your solution is the one that works and allows for a really customized "cascading" list. Really nice. This is a really good example of what to appreciate in Alpha. If you can't use an option the way it was built to be used, then just do it yourself... with 2 lines of code.

[PhilM1965]

Re: Show all items in cascading lists

Hi David,

I am uncertain of the solution working on cascading lists. I may have tried the 'All categories' button approach when I had it set up as a cascading list, and it failed ... I tried many things til I finally got it to work!

I think it would be nice to have a few more options on the built-in items to expose more flexibility though. There are UX components that allow for filters to be applied. As I recall though from my investigations yesterday, the server side filter only allowed a filter against a fields, whereas the client side filter allowed me to enter a custom WHERE clause. It was from examining that code behind the Action Javascript that got the solution for me. I highly recommend anyone new to Alpha to look at the Javascript to see what the Action Javascript is doing on your behalf.

The {dialog.object}._filterlist should be consistent, in my opinion ... i.e. not an added filter. If it is one way on a cascading list and different in non-cascading lists, that leads to confusion (it did for me, but that's not unusual!) ... perhaps adding a check-box to say whether the filter is added to the current filter, or overrides it would give the flexibility needed here. Coming from a different RAD system, it takes time to learn the Alpha way of doing things and on occasion, I do miss the flexibility of the other system when it comes to doing things not originally thought of by the creators. I'll get there

But as you say, there is always more than one way to skin a cat.

Cheers,

Phil