Dynamically call method in EL, which is evaluated from a String

Question

i have a submit button. This submit button has an "action" attribute. But this action attribute should always call another function (some kind of generic). So i want to call a function dynamically. This is because i need to reuse this component. I just don't know which Type the action attribute needs (Method, String, etc. ?) and how to refer correctly to the wanted "BeanWithMethodToCall".

@Named
@SessionScoped
public class BeanWithMethodToCall{

   @Inject
   private BeanWhichIsCalledFromEL elBean;

   public void methodToCall(){
      //do something
   }

   public void someLogic(){
      // here the wanted method is set on the bean which is later on called from el
      elBean.setMethodToCall("methodToCall");
   }
}

@Named
@SessionScoped
public class BeanWhichIsCalledFromEL{

   // i don't know the correct type of this :S
   private String method;

   public void setMethodToCall(String method){
      this.method = method;
   }

   // i don't know the correct return type of this :S
   public String getMethodToExecute(){
      //this method is called in the action attribute in the xhtml 
      // and should return a dynamic function to call
   }

}

In EL:

<h:commandButton value="Cancel" action="#{beanWhichIsCalledFromEL.getMethodToExecute()}">
    <f:ajax render="@form"/>
</h:commandButton>

This seems tricky.. I hope somebody can help me. Do i need Reflection ? or an EL Resolver or anything else ??

score 8 · Accepted Answer · edited May 23 '17 at 12:01

8

Use the brace notation #{bean[foo]} to evaluate "dynamic" method and property names.

Your specific case can be solved as below:

<h:commandButton ... action="#{bean[bean.methodToExecute]}">

Dynamically call method in EL, which is evaluated from a String

1 Answers1

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