Fallback Values

The .Fallback() method provides a default value when a translation key is missing or invalid.

Syntax

string result = key.Tr(table).Fallback(defaultValue);

Basic Usage

// If "missing.key" doesn't exist, returns "Default Text"
string text = "missing.key".Tr("UI").Fallback("Default Text");

// If key exists, returns the translated value
string text = "menu.title".Tr("UI").Fallback("Untitled");

When Fallback Is Used

Fallback is returned when:

1. The key doesn't exist in the table

2. The column for current locale is missing

3. The cell value is null or empty

Use Cases

Missing Keys

Provide graceful degradation:

string GetItemName(string itemKey)
{
    return $"item.{itemKey}.name"
        .Tr("Items")
        .Fallback("Unknown Item");
}

Development Placeholders

Use fallbacks during development:

// Translation not ready yet
string tooltip = "feature.new.tooltip"
    .Tr("UI")
    .Fallback("[Tooltip Coming Soon]");

User-Generated Content

Handle dynamic content safely:

string GetCustomName(string userKey)
{
    return userKey.Tr("UserContent").Fallback(userKey);
    // Returns the key itself if translation missing
}

Chaining

Fallback can be combined with other methods:

string text = "item.apple"
    .Tr("Items")
    .Child("description")
    .Locale(Locale.KoKR)
    .Fallback("No description available");

Dynamic Fallbacks

Generate fallback values dynamically:

string GetLocalizedText(string key, string table)
{
    string fallback = $"[Missing: {key}]";
    return key.Tr(table).Fallback(fallback);
}

Empty String vs Fallback

// Empty string in table cell returns empty string
string text1 = "empty.key".Tr("UI").Fallback("Fallback");
// Returns: "" (if cell exists but is empty)

// Missing key returns fallback
string text2 = "missing.key".Tr("UI").Fallback("Fallback");
// Returns: "Fallback"

Best Practices

Meaningful Fallbacks

Provide fallbacks that make sense in context:

// Good: descriptive fallback
string name = itemKey.Tr("Items").Fallback("Unnamed Item");

// Bad: technical fallback
string name = itemKey.Tr("Items").Fallback("ERROR_TRANSLATION_MISSING");

Debug Mode

Use fallbacks to identify missing translations during development:

#if UNITY_EDITOR
string text = key.Tr(table).Fallback($"[MISSING: {table}.{key}]");
#else
string text = key.Tr(table).Fallback("");
#endif

UI Default Text

Set fallback to match your UI's default state:

public class HealthBar : MonoBehaviour
{
    public TextMeshProUGUI label;

    void Start()
    {
        label.text = "ui.health.label"
            .Tr("UI")
            .Fallback("Health"); // Matches default Prefab text
    }
}

Performance

Fallback values are only evaluated when needed (lazy evaluation):

// This expensive call only runs if key is missing
string text = "menu.title".Tr("UI").Fallback(ExpensiveStringGeneration());