Invalid postback or callback argument. Event validation is enabled

Sep 28, 2009 at 6:39 PM

whenever i use the cascading dropdown feature and save my selections i get the following error message: "Invalid postback or callback argument. Event validation is enabled......" This only occures when i use dropdown menus (choice field) for the form and not lookup columns. what i want to do is use a regular dropdown and not a lookup columns so i can use their vaules elsewhere, is that possible, i included all possible choices in the dropdowns that are in the lookup list. Also is there a way to only display unique values from the lookup list in the dropdown.

Coordinator
Sep 28, 2009 at 6:52 PM

You need to store your values in a list so that you can specify the relationship between the columns.  You can set up a Site Column which also derives its values from the list so that you can use the values elsewhere.  In some ways, this is actually a better approach, as with the values in lists the content management tasks can be delegated to "regular" users more easily.

M.

Sep 28, 2009 at 7:05 PM
sympmarc wrote:

You need to store your values in a list so that you can specify the relationship between the columns.  You can set up a Site Column which also derives its values from the list so that you can use the values elsewhere.  In some ways, this is actually a better approach, as with the values in lists the content management tasks can be delegated to "regular" users more easily.

M.

Thanks for the quick response, I do have my items stored in a list. My List is setup with 3 fields Country, State, and City, with the associations. the ParentColumn and ChildColumn are set to these values. What i want to be able to do is set the actual field on the form itself(The one that is pulling these value) to be a dropdown (choice field) instead of a lookup. i've tried this and the cascading works just fine. its only when i try to save my changes that i get the above error. I'm going to assume from your message above that i can only make them lookup columns. In reguards to my second question is there away to only show unique values in the dropdowns on the form itself? the second downdown gets filled with multiple copies of the same state.

Coordinator
Sep 28, 2009 at 7:09 PM

You'll want to have two separate lists:

  • States, which has one item per State, with the Country for each, and
  • Cities, which has one item per City, with the State for each

The approach here is just like relational database tables.

Why do you want to use a Choice column instead of a Lookup?

M.

Sep 28, 2009 at 7:27 PM

Ok, i can do two seperate lists. as for why i want to use choice instead of lookups several reasons, Mostly, I want to be able to use the selected value in a SharePoint Designer workflow and also in a custom solution that doesn’t work with lookups. I also do not like the fact that the lookups are displayed as links in the lists, I want to show the users its value but don’t want them clicking it since it will take them to the item view and then to the other list confusing them.

Coordinator
Sep 28, 2009 at 7:37 PM

You can customize the form if you don't want to display the links on the Lookup values.  (You could also remove the links with jQuery.)

As for the workflow and custom solution, no idea there, obviously, but I'd be surprised if you can't get them to work with Lookup columns.

M.

Sep 28, 2009 at 9:36 PM

ok, i also noticed that i have an option of Chose City..., and if i leave that option selected and then click ok i get the exact same error message even using lookup fields.

Coordinator
Sep 28, 2009 at 9:38 PM

That sounds like a bug.  I'll check on that.  Thanks for pointing it out.

M.

Coordinator
Sep 28, 2009 at 9:39 PM
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