Reusable and less-verbose JSF code via OmniFaces utilities API

Constantin Alin

To make JSF life easier

JSFOmniFaces utilities are for

OmniFaces utilities location

org.omnifaces.utilorg.omnifaces.utilorg.omnifaces.util

How many utilities are in OmniFaces

org.omnifaces.util

OmniFaces Showcase

OmniFaces is always up to date and is continuously getting better

OmniFaces is NOT only about 300+ utilitiesOmniFaces is a utility library for JSF and a comprehensive compendium ofprogramming techniques, design patterns and recipes for JSF developers.

What we will cover here ?

• Quick overview of OmniFaces utilities• Shortcuts to access the most used JSF artifacts• Less-verbose utilities methods• Advanced utilities methods

Quick overview of OmniFaces utilitiesor

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Shortcuts

Advanced Less-verbose

ShortcutsQuick access to the most used JSF artifacts

Faces Context

FacesContext

FacesContext fc = Faces.getContext();

// FacesContext for an ELContextFacesContext fc = Faces.getContext(el_context);

FacesContext fc = FacesContext.getCurrentInstance();

// FacesContext for an ELContextFacesContext fc = (FacesContext) el_context.getContext(FacesContext.class);

External Context

ExternalContext

ExternalContext ec = Faces.getExternalContext();

ExternalContext ec = FacesContext.getCurrentInstance().getExternalContext();

EL Context

ELContext

ELContext el = Faces.getELContext();

ELContext el = FacesContext.getCurrentInstance().getELContext();

Partial View Context

PartialViewContext

PartialViewContext pvc = Ajax.getContext();

PartialViewContext pvc = FacesContext.getCurrentInstance().getPartialViewContext();

HTTP Servlet Request

HttpServletRequest

HttpServletRequest request = Faces.getRequest();

HttpServletRequest request = (HttpServletRequest) FacesContext. getCurrentInstance().getExternalContext().getRequest();

Less-verboseBoost the speed of development and obtain a less-verbose

and easy to maintain code

Less-verbose

Facelet Context

FaceletContext flc = Faces.getFaceletContext();

private static final String[] FACELET_CONTEXT_KEYS = { FaceletContext.FACELET_CONTEXT_KEY, "com.sun.faces.facelets.FACELET_CONTEXT", "javax.faces.FACELET_CONTEXT" };

// pass the FacesContextpublic static FaceletContext getFaceletContext(FacesContext context) { Map<Object, Object> contextAttributes = context.getAttributes(); for (String key : FACELET_CONTEXT_KEYS) { FaceletContext faceletContext = (FaceletContext) contextAttributes.get(key); if (faceletContext != null) { return faceletContext; } } return null;}

Include Composite Component

Less-verbose

Components.includeCompositeComponent(parent, "customs", "/welcome.xhtml", "welcomeMsgId", attributes);

public static UIComponent includeCompositeComponent(UIComponent parent, String libraryName, String tagName, String id, Map<String, String> attributes) { String taglibURI = "http://xmlns.jcp.org/jsf/composite/" + libraryName; Map<String, Object> attrs = (attributes == null) ? null : new HashMap<String, Object>(attributes);

FacesContext context = FacesContext.getCurrentInstance(); UIComponent composite = context.getApplication().getViewHandler() .getViewDeclarationLanguage(context, context.getViewRoot().getViewId()) .createComponent(context, taglibURI, tagName, attrs); composite.setId(id); parent.getChildren().add(composite); return composite;}

Add Script to Body

Less-verbose

UIComponent uicomp = Components.addScriptToBody(snippetOfJS);

public static UIComponent addScriptToBody(String script) { UIOutput outputScript = createScriptResource(); UIOutput content = new UIOutput(); content.setValue(script); outputScript.getChildren().add(content); return addComponentResource(outputScript, "body");}

public static final String RENDERER_TYPE_JS = "javax.faces.resource.Script";private static UIOutput createScriptResource() { UIOutput outputScript = new UIOutput(); outputScript.setRendererType(RENDERER_TYPE_JS); return outputScript;}

private static UIComponent addComponentResource(UIComponent resource, String target) { FacesContext context = FacesContext.getCurrentInstance(); context.getViewRoot().addComponentResource(context, resource, target); return resource;}

Get Metadata Attributes

Less-verbose

Map<String,Object> metattr = Faces.getMetadataAttributes("index.xhtml");

public static Map<String, Object> getMetadataAttributes(FacesContext context, String viewId) { ViewHandler viewHandler = context.getApplication().getViewHandler(); ViewDeclarationLanguage vdl = viewHandler.getViewDeclarationLanguage(context, viewId); ViewMetadata metadata = vdl.getViewMetadata(context, viewId);

return (metadata != null) ? metadata.createMetadataView(context).getAttributes() : Collections.<String, Object>emptyMap();}

Get FacesServlet Registration

Less-verbose

ServletRegistration sr = Platform.getFacesServletRegistration(request.getServletContext());

public static ServletRegistration getFacesServletRegistration(ServletContext servletContext) { ServletRegistration facesServletRegistration = null;

for (ServletRegistration registration : servletContext.getServletRegistrations().values()) { if (registration.getClassName().equals(FacesServlet.class.getName())) { facesServletRegistration = registration; break; } }

return facesServletRegistration;}

AdvancedSave time, nerves and hours of researching by using the OmniFaces

advanced and robust solutions

Create AJAX Behavior

Advanced

AjaxBehavior ajaxBehavior = Components.createAjaxBehavior("#{commandBean.save}");

public static AjaxBehavior createAjaxBehavior(String expression) { FacesContext context = FacesContext.getCurrentInstance(); AjaxBehavior behavior = (AjaxBehavior) context.getApplication().createBehavior(AjaxBehavior.BEHAVIOR_ID); final MethodExpression method = createVoidMethodExpression(expression, AjaxBehaviorEvent.class); behavior.addAjaxBehaviorListener(new AjaxBehaviorListener() { @Override public void processAjaxBehavior(AjaxBehaviorEvent event) throws AbortProcessingException { method.invoke(getELContext(), new Object[] { event }); } }); return behavior;}

public static MethodExpression createVoidMethodExpression(String expression, Class<?>... parameterTypes) { return createMethodExpression(expression, Void.class, parameterTypes);}

public static MethodExpression createMethodExpression(String expression, Class<?> returnType, Class<?>... parameterTypes) {

FacesContext context = FacesContext.getCurrentInstance(); return context.getApplication().getExpressionFactory().createMethodExpression( context.getELContext(), expression, returnType, parameterTypes);}

Has Invoked Submit

Advanced

boolean hasInvokedSubmit = Components.hasInvokedSubmit(foo_uicomp);

public static boolean hasInvokedSubmit(UIComponent component) { FacesContext context = FacesContext.getCurrentInstance();

if (!context.isPostback()) { return false; }

String clientId = stripIterationIndexFromClientId(component.getClientId(context)); Map<String, String> params = context.getExternalContext().getRequestParameterMap(); if (context.getPartialViewContext().isAjaxRequest()) { String source = params.get("javax.faces.source"); if (source != null) { return clientId.equals(stripIterationIndexFromClientId(source)); } }

if (component instanceof UICommand) { for (String name : params.keySet()) { if (name.startsWith("javax.faces.")) { continue; // Quick skip. } if (clientId.equals(stripIterationIndexFromClientId(name))) { return true; } } } return false;}

private static String stripIterationIndexFromClientId(String clientId) { String separatorChar = Character.toString(UINamingContainer.getSeparatorChar(getContext())); return clientId.replaceAll(quote(separatorChar) + "[0-9]+" + quote(separatorChar), separatorChar);}

Set Script Resource as Rendered

Advanced

Hacks.setScriptResourceRendered(context, new ResourceIdentifier(script_component));

public static void setScriptResourceRendered(FacesContext context, ResourceIdentifier id) { setMojarraResourceRendered(context, id); if (isMyFacesUsed()) { setMyFacesResourceRendered(context, MYFACES_RENDERED_SCRIPT_RESOURCES_KEY, id); }}

private static final String MYFACES_RENDERED_SCRIPT_RESOURCES_KEY ="org.apache.myfaces.RENDERED_SCRIPT_RESOURCES_SET";

private static void setMojarraResourceRendered(FacesContext context, ResourceIdentifier id) { context.getAttributes().put(id.getName() + id.getLibrary(), true);}

private static void setMyFacesResourceRendered(FacesContext context, String key, ResourceIdentifier id) { getMyFacesResourceMap(context, key).put(getMyFacesResourceKey(id), true);}

private static Map<String, Boolean> getMyFacesResourceMap(FacesContext context, String key) { Map<String, Boolean> map = getContextAttribute(context, key); if (map == null) { map = new HashMap<>(); setContextAttribute(context, key, map); } return map;}

private static String getMyFacesResourceKey(ResourceIdentifier id) { String library = id.getLibrary(); String name = id.getName(); return (library != null) ? (library + '/' + name) : name;}

Is MyFaces Used

Advanced

boolean isMyFacesAround = Hacks.isMyFacesUsed();

private static final String MYFACES_PACKAGE_PREFIX = "org.apache.myfaces.";public static boolean isMyFacesUsed() { if (myFacesUsed == null) { FacesContext context = FacesContext.getCurrentInstance();

if (context != null) { myFacesUsed = context.getClass().getPackage().

getName().startsWith(MYFACES_PACKAGE_PREFIX); } else {

return false; } } return myFacesUsed;}

Build View

Advanced

UIViewRoot anotherView = Components.buildView("foo.xhtml");

public static UIViewRoot buildView(String viewId) throws IOException { FacesContext context = FacesContext.getCurrentInstance(); String normalizedViewId = normalizeViewId(context, viewId); ViewHandler viewHandler = context.getApplication().getViewHandler(); UIViewRoot view = viewHandler.createView(context, normalizedViewId); FacesContext temporaryContext = new TemporaryViewFacesContext(context, view);

try { setContext(temporaryContext); viewHandler.getViewDeclarationLanguage(temporaryContext, normalizedViewId).buildView(temporaryContext, view); } finally { setContext(context); } return view;}

private static class TemporaryViewFacesContext extends FacesContextWrapper { …}

Resources

http://omnifaces-fans.org/

Source Code

http://balusc.omnifaces.org/ http://arjan-tijms.omnifaces.org/

Resources

Thank you!