p:confirm 不实现状态保存，因此在第一个 JSF 生命周期后它会丢失其属性值。它还在视图构建时仅评估一次 EL。
如何解决状态保存问题。
您可以扩展 PrimeFaces 的 ConfirmBehavior，实现 saveState、restoreState，并通过 behavior-id org.primefaces.behavior.ConfirmBehavior 覆盖 faces-config.xml 中的原始行为。然后，您将能够在后续请求中渲染和重新渲染 p:confirm。
如何修复状态保存和重新评估 EL 绑定属性值。
你应该创建你自己的 my:confirm，因为你需要一个自定义的 taghandler，而且你不能用不丑的方式替换另一个 taglibrary 的 tag 的 taghandler。
创建 ConfirmBehavior。
package my;
import javax.faces.FacesException;
import javax.faces.component.UIComponent;
import javax.faces.component.behavior.ClientBehaviorContext;
import javax.faces.context.FacesContext;
import org.primefaces.behavior.base.AbstractBehavior;
import org.primefaces.component.api.Confirmable;
import org.primefaces.json.JSONObject;
public class ConfirmBehavior extends AbstractBehavior {
public final static String BEHAVIOR_ID = "my.ConfirmBehavior";
@Override
public String getScript(ClientBehaviorContext behaviorContext) {
FacesContext context = behaviorContext.getFacesContext();
UIComponent component = behaviorContext.getComponent();
String source = component.getClientId(context);
String headerText = JSONObject.quote(this.getHeader());
String messageText = JSONObject.quote(this.getMessage());
if (component instanceof Confirmable) {
String script = "PrimeFaces.confirm({source:\"" + source + "\",header:" + headerText + ",message:"
+ messageText + ",icon:\"" + getIcon() + "\"});return false;";
((Confirmable) component).setConfirmationScript(script);
return null;
} else {
throw new FacesException("Component " + source + " is not a Confirmable. ConfirmBehavior can only be "
+ "attached to components that implement org.primefaces.component.api.Confirmable interface");
}
}
public String getHeader() {
return eval(PropertyKeys.header, null);
}
public void setHeader(String header) {
setLiteral(PropertyKeys.header, header);
}
public String getMessage() {
return eval(PropertyKeys.message, null);
}
public void setMessage(String message) {
setLiteral(PropertyKeys.message, message);
}
public String getIcon() {
return eval(PropertyKeys.icon, null);
}
public void setIcon(String icon) {
setLiteral(PropertyKeys.icon, icon);
}
public enum PropertyKeys {
header(String.class), message(String.class), icon(String.class);
final Class<?> expectedType;
PropertyKeys(Class<?> expectedType) {
this.expectedType = expectedType;
}
}
@Override
protected Enum<?>[] getAllProperties() {
return PropertyKeys.values();
}
}
创建 ConfirmBehaviorHandler。
package my;
import javax.faces.application.Application;
import javax.faces.view.facelets.BehaviorConfig;
import javax.faces.view.facelets.FaceletContext;
import javax.faces.view.facelets.TagAttribute;
import org.primefaces.behavior.base.AbstractBehaviorHandler;
public class ConfirmBehaviorHandler extends AbstractBehaviorHandler<ConfirmBehavior> {
private final TagAttribute header;
private final TagAttribute message;
private final TagAttribute icon;
public ConfirmBehaviorHandler(BehaviorConfig config) {
super(config);
this.header = this.getAttribute(ConfirmBehavior.PropertyKeys.header.name());
this.message = this.getAttribute(ConfirmBehavior.PropertyKeys.message.name());
this.icon = this.getAttribute(ConfirmBehavior.PropertyKeys.icon.name());
}
@Override
protected ConfirmBehavior createBehavior(FaceletContext ctx, String eventName) {
Application application = ctx.getFacesContext().getApplication();
ConfirmBehavior behavior = (ConfirmBehavior) application.createBehavior(ConfirmBehavior.BEHAVIOR_ID);
setBehaviorAttribute(ctx, behavior, this.header, ConfirmBehavior.PropertyKeys.header.expectedType);
setBehaviorAttribute(ctx, behavior, this.message, ConfirmBehavior.PropertyKeys.message.expectedType);
setBehaviorAttribute(ctx, behavior, this.icon, ConfirmBehavior.PropertyKeys.icon.expectedType);
return behavior;
}
}
在 faces-config.xml 中注册 ConfirmBehavior。
<?xml version="1.0" encoding="utf-8"?>
<faces-config xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-facesconfig_2_2.xsd"
version="2.2">
<behavior>
<behavior-id>my.ConfirmBehavior</behavior-id>
<behavior-class>my.ConfirmBehavior</behavior-class>
</behavior>
</faces-config>
在您的标记库 my.taglib.xml 中注册 ConfirmBehaviorHandler。
<?xml version="1.0" encoding="UTF-8"?>
<facelet-taglib xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-facelettaglibrary_2_2.xsd"
version="2.2">
<namespace>http://mycompany.ru/my</namespace>
<tag>
<tag-name>confirm</tag-name>
<behavior>
<behavior-id>my.ConfirmBehavior</behavior-id>
<handler-class>my.ConfirmBehaviorHandler</handler-class>
</behavior>
</tag>
</facelet-taglib>
现在您可以像使用 p:confirm 一样使用 my:confirm，但具有状态保存和动态 EL 评估功能。