BUG? Context Variables not updating correctly in some situations

[TML]

I have the following code on the OnChange of a dropdown control.

UpdateContext(
    {
        vSite: ddSiteCode.Selected.Value,
        vDateKey: Value(
            Text(
                dteEffectiveDate.SelectedDate,
                "[$-en-US]yyyymmdd"
            )
        ),
        vSiteKey: LookUp(
            UsersAndSites,
            Site_Code = vSite
        ).Site_Key
    }
);
Set(
    gDebugText,
    Concatenate(
        gDebugText,
        gRET,
        "vSite = ",
        vSite,
        gRET,
        "vSiteKey = ",
        Text(vSiteKey),
        gRET,
        "Lookup = ",
        Text(
            LookUp(
                UsersAndSites,
                Site_Code = vSite
            ).Site_Key
        )
    )
);

vSite and vDateKey get set correctly, but vSiteKey is delayed updating. The Lookup show the correct value.

For instance if I have these valuse in the collection UsersAndSites:

Site_Code    Site_Key    User_Name

MAC6            154           JohnS

MAC9            728           PhilK

WLDD           503           CarolB

I have a multiline textbox control set to display the contents of  global variable gDebugText.

The first time I change the dropdown and pick "MAC6".

The second time I select "MAC9".

The thrid time I select  "WLDD".

This is what the gDebugText shows. I have seperated each dropdown change with a double line:

==============

vSite = MAC6
vSiteKey = 0
Lookup = 154

==============

vSite = MAC9
vSiteKey = 154
Lookup = 728

==============

vSite = WLDD
vSiteKey = 154
Lookup = 503

==============

vSiteKey updated on the second OnChange to what it should have been on the first OnChange.  Every OnChange after that, it would not update and stayed at 154. vSite and vDateKey are updating correctly as are the other context variables in my app, as far as I have found so far.

HELP!

[Meneghino · Accepted solution]

Try to use the following instead of the first part of your code.  It could be that you need to split into two:

UpdateContext(
    {
        vSite: ddSiteCode.Selected.Value,
        vDateKey: Value(
            Text(
                dteEffectiveDate.SelectedDate,
                "[$-en-US]yyyymmdd"
            )
        )
    }
);
UpdateContext(
    {
       vSiteKey: LookUp(
            UsersAndSites,
            Site_Code = vSite
        ).Site_Key
    }
); etc. etc.

[TML]

That was the fix.  I have always been told to group all the UpdateContexts together.  Any explanation as to why that needed to be broken out?

[Meneghino]

You basically had used the result of a context update in the same context update, so I guess it was dong the updates in parallel (i.e. using the old value in the second statement).  By breaking it out it is more clear that one update is done and the result used in the second update.