Displaying the relative amount of modifiers

Displaying the relative amount of modifiers

Considering the value of the IRestaurant.DisplayRelativeNumberOfModifiers setting in Syrve POS calculates the number of modifier portions in string form, which is displayed on the UI.

For example, a dish has the Sour cream modifier, which is included in the group of modifiers. For this modifier is run:

• the amount depends on the amount of the main dish
• modifier is free
• the default amount of modifier is 3

Then if IRestaurant.DisplayRelativeNumberOfModifiers is true it will display:

• +2 Sour cream, if increase the amount of the modifier by 2
• - Sour cream, if reducing the amount by 1

If IRestaurant.DisplayRelativeNumberOfModifiers is false the absolute amount of modifier in the dish will be displayed:

• x5 Sour cream, if increase the amount of the modifier by 2
• x2 Sour cream, if reducing the amount by 1

For the convenience of plugin developers and the possibilities to transfer the logic to their UI, here is an example of how to get a line of the number of modifiers.

The CalculateModifierAmountString method takes

• decimal modifierAmount — the amount of portions of the modifier,
• int defaultAmount — the amount of modifier portions by default,
• bool hideIfDefaultAmount — the amount of modifier portions by default “Hide if default quantity”,
• bool isPaid — whether the modifier is a paid,
• bool isAmountIndependentOfParentAmount — whether the “Quantity is independent of the amount of the dish” is set for this modifier.

As a result it returns a line of the form <sign><number> which has to be displayed on the UI near the name of the modifier for the user can see on the screen <sign><number> <modifier name>.

public static string CalculateModifierAmountString(decimal modifierAmount, int defaultAmount, bool hideIfDefaultAmount, bool isPaid, bool isAmountIndependentOfParentAmount)
{
    // Set the method of displaying the amount of group modifiers of a dish.
    var showDeltaAmount = PluginContext.Operations.GetHostRestaurant().DisplayRelativeNumberOfModifiers;

    // If the option "Quantity is independent of the quantity of the dish" is enabled, we always write "+N".
    if (isAmountIndependentOfParentAmount)
        return $"+{modifierAmount}";

    // If the modifier is paid or we show the absolute number of modifiers, we write "×N".
    const string charX = "\u00D7";
    var multiplyAmountString = $"{charX}{modifierAmount}";

    if (isPaid || !showDeltaAmount)
        return multiplyAmountString;

    // Shows the relative amount of modifiers.
    var deltaAmount = modifierAmount - defaultAmount;

    switch (deltaAmount)
    {
        case 1:
            return "+";
        case -1:
            return "-";
        case 0 when hideIfDefaultAmount:
            return string.Empty;
        case 0:
            return multiplyAmountString;
        default:
            return $"{deltaAmount:+#;-#;0}";
    }
}