protected object ProduceValue(
LocalizableProperty targetProperty,
Type propertyType,
ResourceManager resourceManager,
CultureInfo culture,
CultureInfo uiCulture,
bool dataBound,
object dataBoundValueOrValues
)
{
if (propertyType == null)
{
throw new ArgumentNullException(nameof(propertyType));
}
if (resourceManager == null)
{
throw new ArgumentNullException(nameof(resourceManager));
}
if (culture == null)
{
throw new ArgumentNullException(nameof(culture));
}
if (uiCulture == null)
{
throw new ArgumentNullException(nameof(uiCulture));
}
/* Flow:
* 1. Obtain value
* 1.1. Binding -> Get binding value
* 1.2. Multi-binding -> Get all values
* 1.3. Resource -> Get resource value
* 2. Convert value
* 2.1. If Callback -> invoke (with data-bound value only since the resource value (if any) will be used as "StringFormat")
* 2.2. If Converter -> invoke
* 2.3. If NO Bindings AND NO Converter AND NO Callback AND NO StringFormat AND Different-Type -> Use default converter
* 3. Format value
* 3.1. If StringFormat -> Format
* 3.2. If NO StringFormat AND (Bindings OR Callback) AND Resource is string -> Use resource for formatting
*/
#region Obtain value
object resourceValue;
if (string.IsNullOrEmpty(this.Key))
{
// No resource value specified
// Even if no data bindings are specified it is possible that a value is produced by the callback.
// At the very least the StringFormat should be used even if "null" is passed
/*
* if (false == dataBound)
* {
* // No data bindings specified so return the default value
* // return TypeUtils.GetDefaultValue(propertyType);
* // Do NOT throw an exception in order to avoid design-time errors
* //throw new InvalidOperationException("At least a resource or a binding must be specified.");
* }
*/
resourceValue = null;
}
else
{
if (resourceManager == null)
{
// Resource manager not found - return an error message if possible
return(propertyType.IsAssignableFrom(typeof(string)) ? ErrorMessage_ResourceManagerNotFound
: targetProperty != null ? targetProperty.DefaultValue : TypeUtils.GetDefaultValue(propertyType));
}
else
{
resourceValue = resourceManager.GetObject(this.Key, uiCulture);
if (resourceValue == null)
{
// Resource value not found - return an error message if possible
return(propertyType.IsAssignableFrom(typeof(string)) ? string.Format(ErrorMessage_ResourceKeyNotFound, Key)
: targetProperty != null ? targetProperty.DefaultValue : TypeUtils.GetDefaultValue(propertyType));
}
}
}
#endregion
if (dataBound && resourceValue != null && false == resourceValue is string)
{
throw new NotSupportedException("Bindings can be combined only with string resources (since the string resource is used as 'StringFormat').");
}
if (Callback != null && resourceValue != null && false == resourceValue is string)
{
throw new NotSupportedException("A callback can be combined only with string resources (since the string resource is used as 'StringFormat').");
}
// List of data bound values (multi-bindings only)
var dataBoundValueList = dataBoundValueOrValues as object[];
// Indicates if the value is multi-binding
var isMultiBinding = dataBoundValueList?.Length > 1;
if (isMultiBinding)
{
// Converter is not supported for multi-bindings
if (Callback != null)
{
throw new NotSupportedException("Callback is not supported for multi-bindings.");
}
if (Converter != null)
{
throw new NotSupportedException("Converter is not supported for multi-bindings.");
}
// Format the value
var stringFormat = StringFormat.NullIfEmpty() ?? (resourceValue as string).NullIfEmpty();
if (stringFormat == null)
{
throw new InvalidOperationException("Either 'StringFormat' or a resource must be specified when multi-binding is used.");
}
return(string.Format(culture, stringFormat, dataBoundValueList));
}
else if (dataBound)
{
// There is a single data-bound value
var dataValue = dataBoundValueList == null ? dataBoundValueOrValues : dataBoundValueList[0];
if (Callback != null)
{
// Pass the data-bound value to the callback
dataValue = Callback(culture, uiCulture, CallbackParameter, dataValue);
}
if (Converter != null)
{
dataValue = Converter.Convert(dataValue, propertyType, ConverterParameter, culture);
}
// Format the value
var stringFormat = StringFormat.NullIfEmpty() ?? (resourceValue as string).NullIfEmpty();
return(stringFormat == null ? dataValue : string.Format(culture, stringFormat, dataValue));
}
else if (Callback != null)
{
// The callback will produce the value
var dataValue = Callback(culture, uiCulture, CallbackParameter, null);
if (Converter != null)
{
dataValue = Converter.Convert(dataValue, propertyType, ConverterParameter, culture);
}
// Format the value
var stringFormat = StringFormat.NullIfEmpty() ?? (resourceValue as string).NullIfEmpty();
return(stringFormat == null ? dataValue : string.Format(culture, stringFormat, dataValue));
}
else if (resourceValue != null)
{
// There is a resource value only
var dataValue = resourceValue;
if (Converter != null)
{
dataValue = Converter.Convert(dataValue, propertyType, ConverterParameter, culture);
}
else if (false == propertyType.IsAssignableFrom(dataValue.GetType()))
{
// Use the default converter to convert the resource value to the type of the property
dataValue = DefaultValueConverter.Instance.Convert(dataValue, propertyType, null, culture);
}
if (string.IsNullOrEmpty(StringFormat))
{
return(dataValue);
}
else
{
// Format the value
return(string.Format(culture, StringFormat, dataValue));
}
}
else
{
// There is no binding, callback, or a resource value
if (string.IsNullOrEmpty(StringFormat))
{
return(targetProperty != null ? targetProperty.DefaultValue : TypeUtils.GetDefaultValue(propertyType));
}
else
{
// Format the value
return(StringFormat);
}
}
}
