Package jakarta.faces.component.search

package jakarta.faces.component.search

APIs for searching for components in the component tree by using expressions.

This feature has two entry points: for the page author and for the Java programmer. Following is a brief overview of each.

For the Page Author

The following tags support the use of search expressions: <h:message />, <h:messages />, <h:outputLabel />, and <f:ajax />. Each of those tags have one or more attributes whose value must be a client identifier. This feature expands the capability of those attributes to be search expressions. A search expression is space separated list of tokens, where a token can either be a client identifier, a search keyword, or a combination of both. See the specification for SearchKeywordResolver for the list of keywords that must be supported. See the specification for SearchExpressionHandler to learn how the search is performed.

Here is a brief example of the page author use case:

1. <h:body>
2. <h:outputLabel id="label" for="@next" value="Test" />
3. <h:inputText id="input">
4. <f:ajax render="@this @next" />
5. </h:inputText>
6. <h:inputText id="input2" />
7. </h:body>

For the Java Programmer

Using search expressions from Java code offers more flexibility. One must obtain a handle to the SearchExpressionHandler and invoke methods on it as desired.

The following example resolves to a clientId:

1. SearchExpressionHandler handler = facesContext.getApplication().getSearchExpressionHandler();
2. SearchExpressionContext context = SearchExpressionContext.createSearchExpressionContext(facesContext, facesContext.getViewRoot());
3. String clientId = handler.resolveClientId(context, ":form:container:@next");

The following example resolves to a component:

1. SearchExpressionHandler handler = facesContext.getApplication().getSearchExpressionHandler();
2. SearchExpressionContext context = SearchExpressionContext.createSearchExpressionContext(facesContext, facesContext.getViewRoot());
3. handler.resolveComponent(context, ":form:container:@next",
4. new ContextCallback() {
5. public void invokeContextCallback(FacesContext context,
6. UIComponent target) {
7. // target == the resolved component
8. }
9. });

The following example uses multiple expressions and therefor resolves to multiple components:

1. SearchExpressionHandler handler = facesContext.getApplication().getSearchExpressionHandler();
2. SearchExpressionContext context = SearchExpressionContext.createSearchExpressionContext(facesContext, facesContext.getViewRoot());
3. handler.resolveComponents(context, ":form:container:@next :input1 input2:@parent",
4. new ContextCallback() {
5. public void invokeContextCallback(FacesContext context,
6. UIComponent target) {
7. // target == the resolved component
8. }
9. });

Extending the Capabilities of the Component Search Facility

Creation of the SearchExpressionContext

As with other factories in Faces, the FactoryFinder is used by the system to create instances of the SearchExpressionContext which holds state during the operation of this API.

Adding new SearchKewordResolvers

See SearchKeywordResolver for the specification of how the set of keywords can be expanded.

Related Packages

Package	Description
jakarta.faces.component	Fundamental APIs for user interface components.
jakarta.faces.component.behavior	APIs for attaching additional behavior to user interface components.
jakarta.faces.component.html	Specialized user interface component classes for HTML.
jakarta.faces.component.visit	APIs for traversing a user interface component view.

Class	Description
ComponentNotFoundException	Typed FacesException for the SearchExpressionHandler, if a component can't be resolved.
SearchExpressionContext	A context object that is used to hold state relating to resolve a search expression.
SearchExpressionContextFactory	Provide for separation of interface and implementation for the SearchExpressionContext contract.
SearchExpressionHandler	The SearchExpressionHandler is responsible for resolving search expression(s)
SearchExpressionHandlerWrapper	Provides a simple implementation of SearchExpressionHandler that can be subclassed by developers wishing to provide specialized behavior to an existing SearchExpressionHandler instance.
SearchExpressionHint	An enum that specifies hints that impact the behavior of a component tree search.
SearchKeywordContext	SearchKeywordContext provides context information that may be useful to SearchKeywordResolver.resolve(jakarta.faces.component.search.SearchKeywordContext, jakarta.faces.component.UIComponent, java.lang.String) implementations.
SearchKeywordResolver	A SearchKeywordResolver is responsible for resolving a single keyword.
UntargetableComponent	Components implementing this interface are ignored by the algorithm - especially in the implementation of @child(n), @next and @previous.