Saturday, November 21, 2009

JSF : Util Classes

import java.util.Iterator;
import java.util.Locale;
import java.util.Map;
import java.util.MissingResourceException;
import java.util.ResourceBundle;
import javax.el.ELContext;
import javax.el.ExpressionFactory;
import javax.el.MethodExpression;
import javax.el.ValueExpression;
import javax.faces.application.Application;
import javax.faces.application.FacesMessage;
import javax.faces.component.UIComponent;
import javax.faces.component.UIViewRoot;
import javax.faces.context.ExternalContext;
import javax.faces.context.FacesContext;
import javax.servlet.http.HttpServletRequest;
import oracle.adf.model.binding.DCBindingContainer;
/**
* General useful static utilies for working with JSF.
* NOTE: Updated to use JSF 1.2 ExpressionFactory.
*
*/
public class JSFUtils {
private static final String NO_RESOURCE_FOUND = "Missing resource: ";
/**
* Method for taking a reference to a JSF binding expression and returning
* the matching object (or creating it).
* @param expression EL expression
* @return Managed object
*/
public static Object resolveExpression(String expression) {
FacesContext facesContext = getFacesContext();
Application app = facesContext.getApplication();
ExpressionFactory elFactory = app.getExpressionFactory();
ELContext elContext = facesContext.getELContext();
ValueExpression valueExp =
elFactory.createValueExpression(elContext, expression,
Object.class);
return valueExp.getValue(elContext);
}
public static String resolveRemoteUser() {
FacesContext facesContext = getFacesContext();
ExternalContext ectx = facesContext.getExternalContext();
return ectx.getRemoteUser();
}
public static String resolveUserPrincipal() {
FacesContext facesContext = getFacesContext();
ExternalContext ectx = facesContext.getExternalContext();
HttpServletRequest request = (HttpServletRequest)ectx.getRequest();
return request.getUserPrincipal().getName();
}
public static Object resloveMethodExpression(String expression,
Class returnType,
Class[] argTypes,
Object[] argValues) {
FacesContext facesContext = getFacesContext();
Application app = facesContext.getApplication();
ExpressionFactory elFactory = app.getExpressionFactory();
ELContext elContext = facesContext.getELContext();
MethodExpression methodExpression =
elFactory.createMethodExpression(elContext, expression, returnType,
argTypes);
return methodExpression.invoke(elContext, argValues);
}
/**
* Method for taking a reference to a JSF binding expression and returning
* the matching Boolean.
* @param expression EL expression
* @return Managed object
*/
public static Boolean resolveExpressionAsBoolean(String expression) {
return (Boolean)resolveExpression(expression);
}
/**
* Method for taking a reference to a JSF binding expression and returning
* the matching String (or creating it).
* @param expression EL expression
* @return Managed object
*/
public static String resolveExpressionAsString(String expression) {
return (String)resolveExpression(expression);
}
/**
* Convenience method for resolving a reference to a managed bean by name
* rather than by expression.
* @param beanName name of managed bean
* @return Managed object
*/
public static Object getManagedBeanValue(String beanName) {
StringBuffer buff = new StringBuffer("#{");
buff.append(beanName);
buff.append("}");
return resolveExpression(buff.toString());
}
/**
* Method for setting a new object into a JSF managed bean
* Note: will fail silently if the supplied object does
* not match the type of the managed bean.
* @param expression EL expression
* @param newValue new value to set
*/
public static void setExpressionValue(String expression, Object newValue) {
FacesContext facesContext = getFacesContext();
Application app = facesContext.getApplication();
ExpressionFactory elFactory = app.getExpressionFactory();
ELContext elContext = facesContext.getELContext();
ValueExpression valueExp =
elFactory.createValueExpression(elContext, expression,
Object.class);
//Check that the input newValue can be cast to the property type
//expected by the managed bean.
//If the managed Bean expects a primitive we rely on Auto-Unboxing
Class bindClass = valueExp.getType(elContext);
if (bindClass.isPrimitive() || bindClass.isInstance(newValue)) {
valueExp.setValue(elContext, newValue);
}
}
/**
* Convenience method for setting the value of a managed bean by name
* rather than by expression.
* @param beanName name of managed bean
* @param newValue new value to set
*/
public static void setManagedBeanValue(String beanName, Object newValue) {
StringBuffer buff = new StringBuffer("#{");
buff.append(beanName);
buff.append("}");
setExpressionValue(buff.toString(), newValue);
}
/**
* Convenience method for setting Session variables.
* @param key object key
* @param object value to store
*/
public static void storeOnSession(String key, Object object) {
FacesContext ctx = getFacesContext();
Map sessionState = ctx.getExternalContext().getSessionMap();
sessionState.put(key, object);
}
/**
* Convenience method for getting Session variables.
* @param key object key
* @return session object for key
*/
public static Object getFromSession(String key) {
FacesContext ctx = getFacesContext();
Map sessionState = ctx.getExternalContext().getSessionMap();
return sessionState.get(key);
}
public static String getFromHeader(String key) {
FacesContext ctx = getFacesContext();
ExternalContext ectx = ctx.getExternalContext();
return ectx.getRequestHeaderMap().get(key);
}
/**
* Convenience method for getting Request variables.
* @param key object key
* @return session object for key
*/
public static Object getFromRequest(String key) {
FacesContext ctx = getFacesContext();
Map sessionState = ctx.getExternalContext().getRequestMap();
return sessionState.get(key);
}
/**
* Pulls a String resource from the property bundle that
* is defined under the application <message-bundle> element in
* the faces config. Respects Locale
* @param key string message key
* @return Resource value or placeholder error String
*/
public static String getStringFromBundle(String key) {
ResourceBundle bundle = getBundle();
return getStringSafely(bundle, key, null);
}
/**
* Convenience method to construct a FacesMesssage
* from a defined error key and severity
* This assumes that the error keys follow the convention of
* using _detail for the detailed part of the
* message, otherwise the main message is returned for the
* detail as well.
* @param key for the error message in the resource bundle
* @param severity severity of message
* @return Faces Message object
*/
public static FacesMessage getMessageFromBundle(String key,
FacesMessage.Severity severity) {
ResourceBundle bundle = getBundle();
String summary = getStringSafely(bundle, key, null);
String detail = getStringSafely(bundle, key + "_detail", summary);
FacesMessage message = new FacesMessage(summary, detail);
message.setSeverity(severity);
return message;
}
/**
* Add JSF info message.
* @param msg info message string
*/
public static void addFacesInformationMessage(String msg) {
FacesContext ctx = getFacesContext();
FacesMessage fm =
new FacesMessage(FacesMessage.SEVERITY_INFO, msg, "");
ctx.addMessage(getRootViewComponentId(), fm);
}
/**
* Add JSF error message.
* @param msg error message string
*/
public static void addFacesErrorMessage(String msg) {
FacesContext ctx = getFacesContext();
FacesMessage fm =
new FacesMessage(FacesMessage.SEVERITY_ERROR, msg, "");
ctx.addMessage(getRootViewComponentId(), fm);
}
/**
* Add JSF error message for a specific attribute.
* @param attrName name of attribute
* @param msg error message string
*/
public static void addFacesErrorMessage(String attrName, String msg) {
FacesContext ctx = getFacesContext();
FacesMessage fm =
new FacesMessage(FacesMessage.SEVERITY_ERROR, attrName, msg);
ctx.addMessage(getRootViewComponentId(), fm);
}
// Informational getters
/**
* Get view id of the view root.
* @return view id of the view root
*/
public static String getRootViewId() {
return getFacesContext().getViewRoot().getViewId();
}
/**
* Get component id of the view root.
* @return component id of the view root
*/
public static String getRootViewComponentId() {
return getFacesContext().getViewRoot().getId();
}
/**
* Get FacesContext.
* @return FacesContext
*/
public static FacesContext getFacesContext() {
return FacesContext.getCurrentInstance();
}
/*
* Internal method to pull out the correct local
* message bundle
*/
private static ResourceBundle getBundle() {
FacesContext ctx = getFacesContext();
UIViewRoot uiRoot = ctx.getViewRoot();
Locale locale = uiRoot.getLocale();
ClassLoader ldr = Thread.currentThread().getContextClassLoader();
return ResourceBundle.getBundle(ctx.getApplication().getMessageBundle(),
locale, ldr);
}
/**
* Get an HTTP Request attribute.
* @param name attribute name
* @return attribute value
*/
public static Object getRequestAttribute(String name) {
return getFacesContext().getExternalContext().getRequestMap().get(name);
}
/**
* Set an HTTP Request attribute.
* @param name attribute name
* @param value attribute value
*/
public static void setRequestAttribute(String name, Object value) {
getFacesContext().getExternalContext().getRequestMap().put(name,
value);
}
/*
* Internal method to proxy for resource keys that don't exist
*/
private static String getStringSafely(ResourceBundle bundle, String key,
String defaultValue) {
String resource = null;
try {
resource = bundle.getString(key);
} catch (MissingResourceException mrex) {
if (defaultValue != null) {
resource = defaultValue;
} else {
resource = NO_RESOURCE_FOUND + key;
}
}
return resource;
}
/**
* Locate an UIComponent in view root with its component id. Use a recursive way to achieve this.
* @param id UIComponent id
* @return UIComponent object
*/
public static UIComponent findComponentInRoot(String id) {
UIComponent component = null;
FacesContext facesContext = FacesContext.getCurrentInstance();
if (facesContext != null) {
UIComponent root = facesContext.getViewRoot();
component = findComponent(root, id);
}
return component;
}
/**
* Locate an UIComponent from its root component.
* Taken from http://www.jroller.com/page/mert?entry=how_to_find_a_uicomponent
* @param base root Component (parent)
* @param id UIComponent id
* @return UIComponent object
*/
public static UIComponent findComponent(UIComponent base, String id) {
if (id.equals(base.getId()))
return base;
UIComponent children = null;
UIComponent result = null;
Iterator childrens = base.getFacetsAndChildren();
while (childrens.hasNext() && (result == null)) {
children = (UIComponent)childrens.next();
if (id.equals(children.getId())) {
result = children;
break;
}
result = findComponent(children, id);
if (result != null) {
break;
}
}
return result;
}
/**
* Method to create a redirect URL. The assumption is that the JSF servlet mapping is
* "faces", which is the default
*
* @param view the JSP or JSPX page to redirect to
* @return a URL to redirect to
*/
public static String getPageURL(String view) {
FacesContext facesContext = getFacesContext();
ExternalContext externalContext = facesContext.getExternalContext();
String url =
((HttpServletRequest)externalContext.getRequest()).getRequestURL().toString();
StringBuffer newUrlBuffer = new StringBuffer();
newUrlBuffer.append(url.substring(0, url.lastIndexOf("faces/")));
newUrlBuffer.append("faces");
String targetPageUrl = view.startsWith("/") ? view : "/" + view;
newUrlBuffer.append(targetPageUrl);
return newUrlBuffer.toString();
}

// Get the error


String error = iterBind.getError().getMessage();













// Get a session bean

FacesContext ctx = FacesContext.getCurrentInstance();

ExpressionFactory ef = ctx.getApplication().getExpressionFactory();

ValueExpression ve = ef.createValueExpression(ctx.getELContext(), "#{testSessionBean}", TestSession.class);

TestSession test = (TestSession)ve.getValue(ctx.getELContext());



// main jsf page

DCBindingContainer dc = (DCBindingContainer)BindingContext.getCurrent().getCurrentBindingsEntry();

// taskflow binding

DCTaskFlowBinding tf = (DCTaskFlowBinding)dc.findExecutableBinding("dynamicRegion1");

// pagedef of a page fragment

JUFormBinding form = (JUFormBinding) tf.findExecutableBinding("regions_employee_regionPageDef");

// handle to binding container of the region.

DCBindingContainer dcRegion = form;







// return a methodexpression like a control flow case action or ADF pagedef action

private MethodExpression getMethodExpression(String name) {

Class [] argtypes = new Class[1];

argtypes[0] = ActionEvent.class;

FacesContext facesCtx = FacesContext.getCurrentInstance();

Application app = facesCtx.getApplication();

ExpressionFactory elFactory = app.getExpressionFactory();

ELContext elContext = facesCtx.getELContext();

return elFactory.createMethodExpression(elContext,name,null,argtypes);

}



//

RichCommandMenuItem menuPage1 = new RichCommandMenuItem();

menuPage1.setId("page1");

menuPage1.setText("Page 1");

menuPage1.setActionExpression(getMethodExpression("page1"));



RichCommandButton button = new RichCommandButton();

button.setValueExpression("disabled",getValueExpression("#{!bindings."+item+".enabled}"));

button.setId(item);

button.setText(item);

MethodExpression me = getMethodExpression("#{bindings."+item+".execute}");

button.addActionListener(new MethodExpressionActionListener(me));

footer.getChildren().add(button);





// get a value

private ValueExpression getValueExpression(String name) {

FacesContext facesCtx = FacesContext.getCurrentInstance();

Application app = facesCtx.getApplication();

ExpressionFactory elFactory = app.getExpressionFactory();

ELContext elContext = facesCtx.getELContext();

return elFactory.createValueExpression(elContext, name, Object.class);

}

// an example how to use this

RichInputText input = new RichInputText();

input.setValueExpression("value",getValueExpression("#{bindings."+item+".inputValue}"));

input.setValueExpression("label",getValueExpression("#{bindings."+item+".hints.label}"));

input.setId(item);

panelForm.getChildren().add(input);

// find a jsf component

private UIComponent getUIComponent(String name) {

FacesContext facesCtx = FacesContext.getCurrentInstance();

return facesCtx.getViewRoot().findComponent(name) ;

}

// change the locale

Locale newLocale = new Locale(this.language);

FacesContext context = FacesContext.getCurrentInstance();

context.getViewRoot().setLocale(newLocale);
}

**************************************

 public static void writeJavaScriptToClient(String paScript) {
        FacesContext fctx = FacesContext.getCurrentInstance();
        ExtendedRenderKitService erks = null;
        erks =
Service.getRenderKitService(fctx, ExtendedRenderKitService.class);
        erks.addScript(fctx, paScript);
    }

**************************************

/**
     * method for removing Session variables.
     * @param
     *
     */
    public static void removeFromSession(String key) {
        FacesContext ctx = getFacesContext();
        Map sessionState = ctx.getExternalContext().getSessionMap();
        sessionState.remove(key);
    }