2aa99ec0d0
The JSF com.sun.faces.facelets.tag.jsf.ComponentSupport in 2.2.7 started using FacesContext#isPostBack to check if a new component tree is being built prior to attempting to find a child component. In Web Flow where we redirect prior to rendering, and hence lose the value of isPostback (because ResponseStateManagerImpl no longer finds the parameter with the view state), it causes components to be re-created and lose their local values. This change overrides isPostback in FlowFacesContext in order to return true in cases where the UIViewRoot has been restored from flash scope and is fully built. Issue: SWF-1645
Overview
Spring Web Flow facilitates building web applications that require guided navigation -- e.g. a shopping cart, flight check-in, a loan application, and many others. In contrast to stateless, free-form navigation such use cases have a clear start and end point, one or more screens to go through in a specific order, and a set of changes that are not finalized to the end.
A distinguishing feature is the ability to define a flow definition consisting of states, transitions, and data. For example, view states correspond to the individual screens of the flow while transitions are caused by events resulting from the click of a button or a link. Data may be stored in scopes such as flash, view, flow, and others. Scoped data is cleared when it is no longer in scope.
In REST terms a flow represents as a single resource. The same URL used to start the flow is also the URL used to step through the flow (there is also an execution key uniquely identifying the current flow instance). As a result of this approach navigation remains encapsulated in the flow definition.
Some key benefits of using Spring Web Flow:
- A flow abstraction to model "long conversations" in web applications
- Proper encapsulation for navigation rules
- Multiple scopes in which to keep data
- Automatic use of the POST/REDIRECT/GET pattern to avoid browser warnings
- Impossible to return to completed flow sessions via browser back button
- Rapid prototyping of flow requirements
- Development mode in which flow definition changes are detected on the fly
- IDE visualization for flow definitions
- Much more...
Documentation
See the current Javadoc and Reference docs.
Samples
Samples can be found in the spring-webflow-samples Github repository.
Downloading artifacts
Instructions on downloading Spring Web Flow artifacts via Maven and other build systems are available via the project wiki.
Issue Tracking
Spring Web Flow's JIRA issue tracker can be found here. If you think you've found a bug, please consider helping to reproduce it by submitting an issue reproduction project via the spring-webflow-issues repository. The readme provides simple step-by-step instructions.
Getting support
Check out the Spring forums and the spring-webflow tag on StackOverflow. Commercial support is available too.
Building from source
Check out sources:
git clone git://github.com/SpringSource/spring-webflow.git
Compile and test, build all jars, distribution zips and docs:
./gradlew build
Install into your local Maven repository:
./gradlew install
Generate Eclipse settings and then manually import projects:
./import-into-eclipse.sh
The Spring Framework and Spring Web Flow use a very similar build system. For this reason the following Gradle build FAQ would be a very useful read.
Contributing
Pull requests are welcome. You'll be asked to sign our contributor license agreement (CLA). Trivial changes like typo fixes are especially appreciated (just fork and edit!). For larger changes, please search through JIRA for similiar issues, creating a new one if necessary, and discuss your ideas with the Spring Web Flow team.
License
Spring Web Flow is released under version 2.0 of the Apache License.