Web Flow 1 required Spring MVC based flows to manually call
FormAction methods, notably:
bindAndValidate to process form views.
Web Flow 2 now provides automatic model setup and binding using the
model attribute for
Please see the Binding to a Model section for details.
Web Flow 1 used OGNL exclusively for expressions within the flow definitions. Web Flow 2 adds support for Unified EL. Web Flow 2.1 uses Spring EL by default. United EL and OGNL can still be plugged in. Please see Chapter 4, Expression Language (EL) for details.
Flash scope in Web Flow 1 lived across the current request and into the next request. This was conceptually similar to Web Flow 2's view scope concept, but the semantics were not as well defined. In Web Flow 2, flash scope is cleared after every view render. This makes flashScope semantics in Web Flow consistent with other web frameworks.
Web Flow 2 offers significantly improved integration with JSF. Please see Chapter 13, JSF Integration for details.