| At line 1 added 50 lines |
| The RSF NavigationCase system is used to map out the navigation state changes that result from [action] cycles. In plain HTTP terms, every RSF POST submission results in a redirect to a GET view issues to the client, and the NavigationCase that matches the submission is used to determine the URL state in the resulting GET view. |
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| The RSF NavigationCase system was originally inspired by the similarly-named scheme from [JSF], but has become somewhat generalised. |
|
| In RSF, the most convenient way of reporting NavigationCases to the system is to report them from the [producer|ComponentProducer] responsible for rendering the view which contains the [UICommand] control generating the action cycle. This is done by implementing the extra interface [NavigationCaseReporter|https://saffron.caret.cam.ac.uk/svn/projects/RSFUtil/trunk/src/uk/org/ponder/rsf/flow/jsfnav/NavigationCaseReporter.java] in the producer, which reports a list of navigation cases. |
| !!Example |
| {{{ |
| public class AddItemProducer implements ViewComponentProducer, |
| NavigationCaseReporter, ViewParamsReporter { |
| public static final String VIEW_ID = "AddItem"; |
|
| public String getViewID() { |
| return VIEW_ID; |
| } |
| public void fillComponents(UIContainer tofill, ViewParameters viewparams, |
| ComponentChecker checker) { |
| ... |
|
| UICommand.make(addupdateitem, "add-update-item", |
| "#{itemsBean.processActionAdd}"); |
| ... |
| } |
|
| public List reportNavigationCases() { |
| List l = new ArrayList(); |
| l.add(new NavigationCase("added", new SimpleViewParameters( |
| ItemsProducer.VIEW_ID))); |
| return l; |
| } |
| }}} |
|
| In this example, we return a list consisting of a single NavigationCase, which will match when the return value from the method binding {{#{itemsBean.processActionAdd}} } on the single UICommand in this view equals {{"added"}}. |
|
| {{{ |
| public class ItemsBean { |
| ... dependencies |
| public String processActionAdd() { |
| ... process addition |
| return "added"; |
| } |
| } |
| }}} |
|
| In this case since there is just a single control, and a method binding which only ever returns the same result, we could have simplified the NavigationCase above to read only {{{ |
| l.add(new NavigationCase(new SimpleViewParameters(ItemsProducer.VIEW_ID))); |
| }}} |
| !!Advanced uses |
| Unless one is using some kind of [flow|Flows] system, one will stick to one of the arg-constructors for NavigationCase. The dedicated page on [InformalFlows] shows how to set the extra {{flowCondition}} field to take advantage of RSF's idiomatic yet powerful scheme for building up stateful flows incrementally. |
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| The navigation state determined by the NavigationCase system can be further fine-tuned by the use of an [ActionResultInterceptor]. |
