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• Use complex OGNL expressions - WebWork will automatically take care of creating the actual objects for you.
• Use JavaBeans! WebWork can only create objects for you if your objects obey the JavaBean specification and provide no-arg constructions, as well as getters and setters where appropriate.
• Remember that person.name will call getPerson().setName(), but if you are expecting WebWork to create the Person object for you, a setPerson() must also exist.

• Wiki Markup
  For lists and maps, use index notation, such as _people\[0\].name_ or _friends\['patrick'\].name_. Often these HTML form elements are being rendered inside a loop, so you can use the iterator tag's status attribute if you're using [JSP Tags] or the $\{foo_index\} special property if you're using [FreeMarker Tags].

• FOr multiple select boxes, you obviously can't name each individual item using index notation. Instead, name your element simply people.name and WebWork will understand that it should create a new Person object for each selected item and set it's name accordingly.

Advanced Type Conversion

WebWork also has some very advanced, yet easy-to-use, type conversion features. Null property handling will automatically create objects where null references are found. Collection and map support provides intelligent null handling and type conversion for Java Collections. Type conversion error handling provides an easy way to distinguish the difference between an input validation problem from an input type conversion problem.

Null Property Handling

{snippet:id=javadoc|javadoc=true|url=com.opensymphony.xwork.util.InstantiatingNullHandler}

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