Module org.omnifaces
Package org.omnifaces.component.input

Class ScriptParam

  • All Implemented Interfaces:
    EditableValueHolder, PartialStateHolder, StateHolder, TransientStateHolder, ValueHolder, ComponentSystemEventListener, FacesListener, SystemEventListenerHolder, EventListener
    public class ScriptParam
extends OnloadParam

    The <o:scriptParam> is a component that extends the standard <f:viewParam> with support for setting results of client-side evaluated JavaScript code in bean.

    Usage

    It's similar to the <f:viewParam>. 

     <f:metadata>
     <o:scriptParam script="new Date().getTimezoneOffset()" value="#{bean.clientTimeZoneOffset}" />
     <o:scriptParam script="window.screen.width" value="#{bean.clientScreenWidth}" />
     <o:scriptParam script="someFunctionName()" value="#{bean.resultOfSomeFunctionName}" />
 </f:metadata>

    You can use the render attribute to declare which components should be updated when a script parameter has been set. 

     <f:metadata>
     <o:scriptParam script="foo()" value="#{bean.resultOfFoo}" render="fooResult" />
 </f:metadata>
 ...
 <h:body>
     ...
     <h:panelGroup id="fooResult">
         <ui:fragment rendered="#{not empty bean.resultOfFoo}">
             The result of foo() script is: #{bean.resultOfFoo}
         </ui:fragment>
     </h:panelGroup>
     ...
 </h:body>

    Note that as it extends from the standard <f:viewParam>, its built-in conversion and validation functionality is also supported on this component. So, the following is also possible: 

     <f:metadata>
     <o:scriptParam script="window.navigator" value="#{bean.clientNavigator}" />
 </f:metadata>
    With a clientNavigator being an instance of jakarta.json.JsonObject: 
     private JsonObject clientNavigator;
    And this converter: 
     package com.example;

 import java.io.StringReader;
 import jakarta.faces.component.UIComponent;
 import jakarta.faces.context.FacesContext;
 import jakarta.faces.convert.Converter;
 import jakarta.faces.convert.ConverterException;
 import jakarta.faces.convert.FacesConverter;
 import jakarta.json.Json;
 import jakarta.json.JsonObject;

 @FacesConverter(forClass = JsonObject.class)
 public class JsobObjectConverter implements Converter<JsonObject> {

     @Override
     public String getAsString(FacesContext context, UIComponent component, JsonObject modelValue) {
         if (modelValue == null) {
             return "";
         }

         return modelValue.toString();
     }

     @Override
     public JsonObject getAsObject(FacesContext context, UIComponent component, String submittedValue) {
         if (submittedValue == null || submittedValue.isEmpty()) {
             return null;
         }

         try {
             return Json.createReader(new StringReader(submittedValue)).readObject();
         }
         catch (Exception e) {
             throw new ConverterException("Not a valid JSON object", e);
         }
     }
 }

    Events

    When the script params have been set, then any method with the PostScriptParam annotation will be fired: 

     @PostScriptParam
 public void initScriptParams() {
     // ...
 }

    This is useful in case you want to preload the model for whatever is rendered by <o:scriptParam render>.

    Since:
    3.6
    Author:
    Bauke Scholtz
    See Also:
    OnloadParam, PostScriptParam, Faces.getScriptParameters()

    • Field Detail

      • COMPONENT_TYPE

        public static final String COMPONENT_TYPE
        The component type, which is "org.omnifaces.component.input.ScriptParam".
        See Also:
        Constant Field Values

      • EVENT_VALUE

        public static final String EVENT_VALUE
        The omnifaces event value, which is "setScriptParamValues".
        See Also:
        Constant Field Values

    • Constructor Detail

      • ScriptParam

        public ScriptParam()

    • Method Detail

      • getInitScript

        protected String getInitScript​(FacesContext context)
        Description copied from class: OnloadParam
        Returns script which should be executed upon initialization of a new view.
        Overrides:
        getInitScript in class OnloadParam
        Parameters:
        context - The involved faces context.
        Returns:
        Script which should be executed upon initialization of a new view.

      • getScript

        public String getScript()
        Returns the script to be evaluated.
        Returns:
        The script to be evaluated.

      • setScript

        public void setScript​(String script)
        Sets the script to be evaluated.
        Parameters:
        script - The script to be evaluated.

      • isScriptParamRequest

        public static boolean isScriptParamRequest​(FacesContext context)
        Returns true if the current request is triggered by a script param request. I.e. if it is initiated by OmniFaces.ScriptParam.setScriptParamValues() script which runs on page load.
        Parameters:
        context - The involved faces context.
        Returns:
        true if the current request is triggered by a script param request.