Interface IPropertyValueConverter

Provides published content properties conversion service.

Namespace: Umbraco.Cms.Core.PropertyEditors

Assembly: Umbraco.Core.dll

Syntax

public interface IPropertyValueConverter : IDiscoverable

Remarks

This is not a simple "value converter" because it really works only for properties.

Methods

View Source

ConvertIntermediateToObject(IPublishedElement, IPublishedPropertyType, PropertyCacheLevel, Object, Boolean)

Converts a property intermediate value to an Object value.

Declaration

object ConvertIntermediateToObject(IPublishedElement owner, IPublishedPropertyType propertyType, PropertyCacheLevel referenceCacheLevel, object inter, bool preview)

Parameters

Type	Name	Description
IPublishedElement	owner	The property set owning the property.
IPublishedPropertyType	propertyType	The property type.
PropertyCacheLevel	referenceCacheLevel	The reference cache level.
System.Object	inter	The intermediate value.
System.Boolean	preview	A value indicating whether conversion should take place in preview mode.

Returns

Type	Description
System.Object	The result of the conversion.

Remarks

The converter should know how to convert a null intermediate value, or any intermediate value indicating that no value has been assigned to the property. It is up to the converter to determine what to return in that case: either null, or the default value...

The referenceCacheLevel is passed to the converter so that it can be, in turn, passed to eg a PublishedFragment constructor. It is used by the fragment and the properties to manage the cache levels of property values. It is not meant to be used by the converter.

View Source

ConvertIntermediateToXPath(IPublishedElement, IPublishedPropertyType, PropertyCacheLevel, Object, Boolean)

Converts a property intermediate value to an XPath value.

Declaration

object ConvertIntermediateToXPath(IPublishedElement owner, IPublishedPropertyType propertyType, PropertyCacheLevel referenceCacheLevel, object inter, bool preview)

Parameters

Type	Name	Description
IPublishedElement	owner	The property set owning the property.
IPublishedPropertyType	propertyType	The property type.
PropertyCacheLevel	referenceCacheLevel	The reference cache level.
System.Object	inter	The intermediate value.
System.Boolean	preview	A value indicating whether conversion should take place in preview mode.

Returns

Type	Description
System.Object	The result of the conversion.

Remarks

If successful, the result should be either null, a string, or an XPathNavigator instance. Whether an xml-whitespace string should be returned as null or literally, is up to the converter.

The converter may want to return an XML fragment that represent a part of the content tree, but should pay attention not to create infinite loops that would kill XPath and XSLT.

View Source

ConvertSourceToIntermediate(IPublishedElement, IPublishedPropertyType, Object, Boolean)

Converts a property source value to an intermediate value.

Declaration

object ConvertSourceToIntermediate(IPublishedElement owner, IPublishedPropertyType propertyType, object source, bool preview)

Parameters

Type	Name	Description
IPublishedElement	owner	The property set owning the property.
IPublishedPropertyType	propertyType	The property type.
System.Object	source	The source value.
System.Boolean	preview	A value indicating whether conversion should take place in preview mode.

Returns

Type	Description
System.Object	The result of the conversion.

Remarks

The converter should know how to convert a null source value, meaning that no value has been assigned to the property. The intermediate value can be null.

With the XML cache, source values come from the XML cache and therefore are strings.

With objects caches, source values would come from the database and therefore be either ints, DateTimes, decimals, or strings.

The converter should be prepared to handle both situations.

When source values are strings, the converter must handle empty strings, whitespace strings, and xml-whitespace strings appropriately, ie it should know whether to preserve white spaces.

View Source

GetPropertyCacheLevel(IPublishedPropertyType)

Gets the property cache level.

Declaration

PropertyCacheLevel GetPropertyCacheLevel(IPublishedPropertyType propertyType)

Parameters

Type	Name	Description
IPublishedPropertyType	propertyType	The property type.

Returns

Type	Description
PropertyCacheLevel	The property cache level.

View Source

GetPropertyValueType(IPublishedPropertyType)

Gets the type of values returned by the converter.

Declaration

Type GetPropertyValueType(IPublishedPropertyType propertyType)

Parameters

Type	Name	Description
IPublishedPropertyType	propertyType	The property type.

Returns

Type	Description
Type	The CLR type of values returned by the converter.

Remarks

Some of the CLR types may be generated, therefore this method cannot directly return a Type object (which may not exist yet). In which case it needs to return a ModelType instance.

View Source

IsConverter(IPublishedPropertyType)

Gets a value indicating whether the converter supports a property type.

Declaration

bool IsConverter(IPublishedPropertyType propertyType)

Parameters

Type	Name	Description
IPublishedPropertyType	propertyType	The property type.

Returns

Type	Description
System.Boolean	A value indicating whether the converter supports a property type.

View Source

IsValue(Object, PropertyValueLevel)

Determines whether a value is an actual value, or not a value.

Declaration

bool? IsValue(object value, PropertyValueLevel level)

Parameters

Type	Name	Description
System.Object	value
PropertyValueLevel	level

Returns

Type	Description
System.Nullable<System.Boolean>

Remarks

Called for Source, Inter and Object levels, until one does not return null.

Can return true (is a value), false (is not a value), or null to indicate that it cannot be determined at the specified level. For instance, if source is a string that could contain JSON, the decision could be made on the intermediate value. Or, if it is a picker, it could be made on the object value (the actual picked object).