Making a RemoteCommand programmatically

What is RemoteCommand

You can find a usage for PrimeFaces RemoteCommand on client side here. RemoteCommand is an implementation of UICommand in PrimeFaces library.

With RemoteCommand you can call a bean method as an ajax call from a client side component callback, for example onChange, onHide, onClick etc.

And in the following it is shown that how you can generate a RemoteCommand and join it to a component programmatically.



Required libraries

import java.util.Map;

import javax.el.MethodExpression;
import javax.faces.application.Application;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.event.MethodExpressionActionListener;

import org.primefaces.component.outputlabel.OutputLabel;
import org.primefaces.component.outputpanel.OutputPanel;
import org.primefaces.component.remotecommand.RemoteCommand;
import org.primefaces.component.selectcheckboxmenu.SelectCheckboxMenu;

RemoteCommand example

FacesContext fc = FacesContext.getCurrentInstance();
Application app = FacesContext.getCurrentInstance().getApplication();

// generate a SelectCheckboxMenu
SelectCheckboxMenu scm = (SelectCheckboxMenu) app.createComponent(SelectCheckboxMenu.COMPONENT_TYPE);
String scmId = "scmId";
scm.setId(scmId);
scm.setLabel("a caption..");
// call remote command named populateLabel from callback method 
// send the component id as a parameter to find the component at back-end 
scm.setOnHide("populateLabel([{name:'scmId', value:'" + scmId + "'}]);");

// prepare a remote command
RemoteCommand remoteCommand = new RemoteCommand();
remoteCommand.setName("populateLabel");
MethodExpression methodExpression = app.getExpressionFactory().createMethodExpression(
  fc.getELContext(), "#{myBean.populateLabelOnHide}", null, new Class<?>[]{Object.class});
remoteCommand.addActionListener(new MethodExpressionActionListener(methodExpression));
remoteCommand.setUpdate(":form:" + scmId);
remoteCommand.setProcess("@this form:" + scmId);

// make output label
OutputLabel outputLabel = (OutputLabel) app.createComponent(OutputLabel.COMPONENT_TYPE);
outputLabel.setValue("SCM label");
outputLabel.setFor(scmId);

// make an output panel and add components into it
OutputPanel panel = (OutputPanel) app.createComponent(OutputPanel.COMPONENT_TYPE);
panel.getChildren().add(scm);
panel.getChildren().add(remoteCommand);

Bean method

public void populateLabelOnHide(Object actionEvent) {
 // find select checkbox menu component id parameter
 FacesContext context = FacesContext.getCurrentInstance();
 Map<String, String> params = context.getExternalContext().getRequestParameterMap();
 String selectCheckboxMenuId = params.get("scmId");

 // find SelectCheckboxMenu component
 SelectCheckboxMenu scm = (SelectCheckboxMenu) findComponentRecursivelyById(selectCheckboxMenuId);

 // make an action on it
 scm.setLabel("Change the caption..");
}

You can findComponentRecursivelyById method here

Please check this also