Button not reliable enabling/disabling

I do something similar and I use a session variable to hold a true/false and set this on the button under the UDDynamic. Example:

$today = Get-Date
New-UDGrid -Container -content {
    New-UDCard -Title 'Start Date' -Content {
        New-UDDatePicker -Id 'date_Start' -Label 'Start Date' -MaximumDate $today -Value $today -Variant static -views @('day') -Format 'MM/dd/yyyy' -OnChange {
            Sync-UDElement -Id 'dyn_Dates'
        }
    }
    New-UDCard -Title 'End Date' -Content {
        New-UDDatePicker -Id 'date_end' -Label 'End Date' -MaximumDate $today -Value $today -Variant static -views @('day') 'MM/dd/yyyy' -OnChange {
            Sync-UDElement -Id 'dyn_Dates'
            Sync-UDElement -Id 'dyn_button'
        }
    }
    New-UDCard -Content {
        New-UDDynamic -Id 'dyn_Dates' -Content {
            $session:StartDate = (Get-UDElement -Id date_Start).value
            $session:EndDate = (Get-UDElement -Id date_end).value
            New-UDTypography -Text "Start Date: $($session:StartDate.tostring('MM/dd/yyyy'))"
            New-UDHtml -Markup '<br>'
            New-UDTypography -Text "End Date: $($session:EndDate.tostring('MM/dd/yyyy'))"
            New-UDHtml -Markup '<br>'
            if ($session:startdate -gt $session:EndDate) {
                New-UDTypography 'The start date must be before the end date' -Style @{color = 'red' }
            }
            New-UDHtml -Markup '<br>'
            New-UDDynamic -Id 'dyn_button' -Content {
                New-UDButton -Id 'btnGetData' -Text 'Get Data' -Disabled:$session:btnDisabled -OnClick {
                    Show-UDToast -Message 'clicked'
                }
            }
            if ($session:startdate -gt $session:EndDate) {
                Show-UDToast -Message 'gt'
                $session:btnDisabled = $true
            } else {
                Show-UDToast -Message 'lt'
                $session:btnDisabled = $false
            }
        }
    }
}

That did it! Strange. I have a few other pages where I do it the way I wrote it and they work fine.

Also I didn’t realize you could add :$boolean to the -disabled parameter. I definitely misunderstood what the docs say when it says it’s a switch parameter.

The boolean on the switch can be done on any switch parameter (AFAIK) and I’m used it in a few of my PowerShell scripts to set the value programmatically.