Prevent Double Submit

PreventDoubleSubmit.java

package com.example.ui.mixins;

import org.apache.tapestry5.annotations.AfterRender;
import org.apache.tapestry5.annotations.InjectContainer;
import org.apache.tapestry5.corelib.components.Form;
import org.apache.tapestry5.ioc.annotations.Inject;
import org.apache.tapestry5.services.javascript.JavaScriptSupport;

/**
 * This class represents fixin for form component that adds client-side logic to page that prevents double form
 * submission. It will mark form as submitted on {@code Tapestry.FORM_PREPARE_FOR_SUBMIT_EVENT} client event and if it
 * has already marked as submitted - will stop {@code Tapestry.FORM_PROCESS_SUBMIT_EVENT} event. After zone was updated
 * with new content, our form will be marked as clear.
 *
 * @author Ivan Khalopik
 */
public class PreventDoubleSubmit {

  @InjectContainer
  private Form form;

  @Inject
  private JavaScriptSupport javascriptSupport;

  /**
   * Renders mixin's JavaScript.
   */
  @AfterRender
  void renderScript() {
    javascriptSupport.addInitializerCall("preventDoubleSubmit", form.getClientId());
  }
}

preventDoubleSubmit.js

// PreventDoubleSubmit fixin script
Tapestry.Initializer.preventDoubleSubmit = function(spec) {
  // find tapestry form
  var tapestryForm = $(spec);
  // bind event handler on prepare for submit
  tapestryForm.observe(Tapestry.FORM_PREPARE_FOR_SUBMIT_EVENT, function() {
    // stop submission if it is already in process
    if (tapestryForm.preventSubmit) {
      tapestryForm.stopObserving(Tapestry.FORM_PROCESS_SUBMIT_EVENT)
    }
    // mark form as in process
    tapestryForm.preventSubmit = true;
  });
  // bind event handler on zone updated event
  document.observe(Tapestry.ZONE_UPDATED_EVENT, function() {
    // remove in process mark from form
    tapestryForm.preventSubmit = false;
  });
};