Package org.apache.tapestry5
Interface EventContext
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- All Known Implementing Classes:
AbstractEventContext
,ArrayEventContext
,EmptyEventContext
,URLEventContext
public interface EventContext
A collection of parameters that may eventually be passed to an event handler method. Includes the ability to coerce or encode parameters as needed.- See Also:
TypeCoercer
,ValueEncoder
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Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method Description <T> T
get(java.lang.Class<T> desiredType, int index)
Extracts a parameter value and coerces or decodes it to the desired type.int
getCount()
Returns the number of parameter values that can be extracted.boolean
isEmpty()
Returnstrue
if this context contains no elements.java.lang.String[]
toStrings()
Extracts the value of each context value as a string.<T> java.util.Optional<T>
tryGet(java.lang.Class<T> desiredType, int index)
Tries to extract a parameter value and coerces or decodes it to the desired type.
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Method Detail
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getCount
int getCount()
Returns the number of parameter values that can be extracted.
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isEmpty
boolean isEmpty()
Returnstrue
if this context contains no elements.- Since:
- 5.8.2
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get
<T> T get(java.lang.Class<T> desiredType, int index)
Extracts a parameter value and coerces or decodes it to the desired type.- Parameters:
desiredType
- the type of value requiredindex
- identifies which parameter value to extract- Returns:
- the value extracted and converted or coerced
- Throws:
java.lang.RuntimeException
- if the value can't be converted or the index is out of range
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tryGet
<T> java.util.Optional<T> tryGet(java.lang.Class<T> desiredType, int index)
Tries to extract a parameter value and coerces or decodes it to the desired type.- Parameters:
desiredType
- the type of value requiredindex
- identifies which parameter value to extract- Returns:
- the value extracted and converted or coerced, wrapped in an Optional, or
Optional.empty()
if index is out of bounds, or the value can't be converted. - Since:
- 5.8.2
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toStrings
java.lang.String[] toStrings()
Extracts the value of each context value as a string.- Returns:
- context values
- Since:
- 5.2.0
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