It is common in an application, that some bindings from random pages are needed when navigating through the application. For this an utility class should be used called JSFUtils. The code is this:
BindingContainer bindings =
(BindingContainer)JSFUtils.resolveExpression(“#{data.mypage_view_bindingsContainerPageDef}”);
DCBindingContainer bindings2 = (DCBindingContainer)bindings;
The part “mypage_view_bindingsContainerPageDef” is the name of the bindings page usage id that corresponds to your page. The usage id can be found in DataBindings.cpx file.
JSFUtils class:
package adfgok.wordpress.eg;
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;
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);
}
/**
* @return
*/
public static String resolveRemoteUser() {
FacesContext facesContext = getFacesContext();
ExternalContext ectx = facesContext.getExternalContext();
return ectx.getRemoteUser();
}
/**
* @return
*/
public static String resolveUserPrincipal() {
FacesContext facesContext = getFacesContext();
ExternalContext ectx = facesContext.getExternalContext();
HttpServletRequest request = (HttpServletRequest)ectx.getRequest();
return request.getUserPrincipal().getName();
}
/**
* @param expression
* @param returnType
* @param argTypes
* @param argValues
* @return
*/
public static Object resolveMethodExpression(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);
}
//*****************************************************************
public static Object invokeMethodExpression(String expr, Class returnType,
Class argType, Object argument) {
return invokeMethodExpression(expr, returnType, new Class[] { argType }, new Object[] { argument });
}
public static Object invokeMethodExpression(String expr, Class returnType,
Class[] argTypes, Object[] args) {
FacesContext fc = FacesContext.getCurrentInstance();
ELContext elctx = fc.getELContext();
ExpressionFactory elFactory =
fc.getApplication().getExpressionFactory();
MethodExpression methodExpr =
elFactory.createMethodExpression(elctx, expr, returnType, argTypes);
return methodExpr.invoke(elctx, args);
}
//*********************************************************************
/**
* 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);
}
/**
* @param key
* @return
*/
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 <code>FacesMesssage</code>
* from a defined error key and severity
* This assumes that the error keys follow the convention of
* using <b>_detail</b> 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();
}
/**
* Programmatic evaluation of EL.
*
* @param el EL to evaluate
* @return Result of the evaluation
*/
public static Object evaluateEL(String el) {
FacesContext facesContext = FacesContext.getCurrentInstance();
ELContext elContext = facesContext.getELContext();
ExpressionFactory expressionFactory = facesContext.getApplication().getExpressionFactory();
ValueExpression exp = expressionFactory.createValueExpression(elContext, el, Object.class);
return exp.getValue(elContext);
}
/**
* Programmatic invocation of a method that an EL evaluates to.
* The method must not take any parameters.
*
* @param el EL of the method to invoke
* @return Object that the method returns
*/
public static Object invokeEL(String el) {
return invokeEL(el, new Class[0], new Object[0]);
}
/**
* Programmatic invocation of a method that an EL evaluates to.
*
* @param el EL of the method to invoke
* @param paramTypes Array of Class defining the types of the parameters
* @param params Array of Object defining the values of the parametrs
* @return Object that the method returns
*/
public static Object invokeEL(String el, Class[] paramTypes, Object[] params) {
FacesContext facesContext = FacesContext.getCurrentInstance();
ELContext elContext = facesContext.getELContext();
ExpressionFactory expressionFactory = facesContext.getApplication().getExpressionFactory();
MethodExpression exp = expressionFactory.createMethodExpression(elContext, el, Object.class, paramTypes);
return exp.invoke(elContext, params);
}
}
adfgok 