public interface SimpleBinding extends Binding
Simple types can be manifested in elements and in attributes. Simple type strategies must be capable of parsing simple values regardless of the form.
Strategy objects must declare how they relate to other strategy objects in the type hierarchy of the type they parse. To allow strategy objects which relate through a type hiearchy to communicate, a value is passed along to strategies as they are executed. As an example, consider the strategies for integer and decimal.
class DecimalStrategy implements Strategy {
...
int getExecutionMode() {
return OVERRIDE;
}
Object parse(InstanceComponent instance, Object value)
throws Exception {
BigDecimal decimal = new BigDecimal(instance.getText());
return decimal;
}
...
}
class IntegerStrategy implements Strategy {
...
int getExecutionMode() {
return AFTER;
}
Object parse(InstanceComponent instance, Object value)
throws Exception {
BigDecimal decimal = (BigDecimal)value;
return decimal.toBigInteger();
}
...
}
In the above example, the decimal strategy is at the top of the hierarchy as it declares its
execution mode as Binding.OVERRIDE
. Therefore it must process the raw text of the
instance being parsed, and transform it into the specific object, in this case an object of type
BigDecimal.
The integer strategy extends the decimal strategy as it declares its execution mode as Binding.AFTER
. Therefore the integer strategy has access to the result of the decimal strategy,
and can simply transform the result of the decimal strategy into its specific type. In this case
an object of type BigInteger.
Modifier and Type | Method and Description |
---|---|
String |
encode(Object object,
String value)
Performs the encoding of the object as a String.
|
Object |
parse(InstanceComponent instance,
Object value)
Parses an instance component (element or attribute) into an object representation.
|
getExecutionMode, getTarget, getType
Object parse(InstanceComponent instance, Object value) throws Exception
instance
- The component being parsed.value
- The result of the parse from another strategy in the type hierarchy. Could be
null if this is the first strategy being executed.Delegate
- objects should not attempt to handle any exceptions.Exception
String encode(Object object, String value) throws Exception
object
- The object being encoded, never null.value
- The string returned from another binding in the type hierachy, which could be
null.Exception
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