Java Time API / JSR310 Type Coercers
Author: Ben Weidig
Add JSR310 / Java Time
CoercionTuples to Tapestry.
With Tapestry 5.5.0 elevating the minimum Java version to 1.8, it should provide
CoercionTuples for the new Java Time API (JSR310):
- Add a
CoercionTuplefor all relevant types
- Add specific tuples to reduce possible mismatches
Type coercion is deeply ingrained in Tapestry. And therefore it should be as mature and complete as possible for its Java version.
The addition of the Java time API is a well thought-out replacement for the previous limited
By adding type coercion for the new types we could encourage developers to use them in their code, instead of working around them missing, or needing to provide their own implementation.
Risks and Assumptions
None to minimal risk is assumed.
For Tapestry itself, no risk can be assumed. Existing type coercers won't be changed, only new ones added.
For user projects a minimal risk of duplicate type coercers exist.
Due to the implementation of
user type coercers will override the newly provided ones.
Instead of automatically including the type coercers we could lock them behind a feature-flag.
Details of Proposed Changes
The Java Time API has well-defined
toString() methods, so we don't need explicit
Type.class --> String.class coercers.
Additional type coercers are needed for type-downgrade (
LocalDateTime.class --> LocalDate.class), due to possible parsing exception between different
String-based output formats.
Following type coerces will be added:
* Year --> Integer * Integer --> Year * Month --> Integer * Integer --> Month * Month --> String (enum) * String --> Month (enum) * String --> YearMonth * YearMonth --> Year * YearMonth --> Month * String --> MonthDay (enum) * MonthDay --> Month (enum) * DayOfWeek --> Integer * Integer --> DayOfWeek * DayOfWeek --> String * String --> DayOfWeek * String --> LocalDate * LocalDate --> YearMonth * LocalDate --> MonthDay * LocalTime --> Long * Long --> LocalTime * String --> LocalTime * String --> LocalDateTime * LocalDateTime --> LocalDate * String --> OffsetDateTime * OffsetDateTime --> OffsetTime * String --> ZoneId * String --> ZoneOffset * String --> ZonedDateTime * ZonedDateTime --> ZoneId * Instant --> Long * Long --> Instant * Duration --> Long * Long --> Duration * String --> Period
All added functionality will be unit tested.