BasePresenter.java

/*
** Module   : BasePresenter.java
** Abstract : BasePresenter implements common business methods available for views.
**
** Copyright (c) 2017, Golden Code Development Corporation.
**
** -#- -I- --Date-- ----------------Description----------------------
** 001 SBI 20170601 Created initial version.
*/
/*
** This program is free software: you can redistribute it and/or modify
** it under the terms of the GNU Affero General Public License as
** published by the Free Software Foundation, either version 3 of the
** License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU Affero General Public License for more details.
**
** You may find a copy of the GNU Affero GPL version 3 at the following
** location: https://www.gnu.org/licenses/agpl-3.0.en.html
** 
** Additional terms under GNU Affero GPL version 3 section 7:
** 
**   Under Section 7 of the GNU Affero GPL version 3, the following additional
**   terms apply to the works covered under the License.  These additional terms
**   are non-permissive additional terms allowed under Section 7 of the GNU
**   Affero GPL version 3 and may not be removed by you.
** 
**   0. Attribution Requirement.
** 
**     You must preserve all legal notices or author attributions in the covered
**     work or Appropriate Legal Notices displayed by works containing the covered
**     work.  You may not remove from the covered work any author or developer
**     credit already included within the covered work.
** 
**   1. No License To Use Trademarks.
** 
**     This license does not grant any license or rights to use the trademarks
**     Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
**     of Golden Code Development Corporation. You are not authorized to use the
**     name Golden Code, FWD, or the names of any author or contributor, for
**     publicity purposes without written authorization.
** 
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** 
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**     Golden Code Development Corporation, FWD, or any author or contributor to
**     the covered work, without written authorization.
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**     versions of the covered work must be marked in a reasonable way to make it
**     clear that the modified work is not originating from Golden Code Development
**     Corporation or FWD.  All modified versions must contain the notices of
**     attribution required in this license.
*/


package com.goldencode.p2j.admin.client.application.home;

import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.logging.Logger;

import com.goldencode.p2j.admin.AdminHelper;
import com.google.gwt.event.shared.GwtEvent;
import com.google.gwt.http.client.URL;
import com.google.gwt.regexp.shared.RegExp;
import com.google.web.bindery.event.shared.EventBus;
import com.gwtplatform.mvp.client.Presenter;
import com.gwtplatform.mvp.client.View;
import com.gwtplatform.mvp.client.proxy.PlaceManager;
import com.gwtplatform.mvp.client.proxy.Proxy;
import com.gwtplatform.mvp.client.proxy.RevealContentHandler;
import com.gwtplatform.mvp.shared.proxy.PlaceRequest;


/**
 * BasePresenter implements common business methods available for views.
 *
 * @param    <V>
 *           A view type
 * @param    <Proxy_>
 *           A controller's proxy type 
 */
public abstract class BasePresenter<V extends View, Proxy_ extends Proxy<?>>
extends Presenter<V, Proxy_>
{
   /** Filter GET parameter */
   public static final String FILTER = "filter";
   
   /** The call logger */
   protected Logger logger = Logger.getLogger(getClass().getSimpleName());
   
   /** Place manager */
   private final PlaceManager placeManager;
   
   /** Filter regular expression */
   protected RegExp filterExp;

   /**
    * Creates a base presenter for the GWTP framework.
    * 
    * @param    eventBus
    *           The event bus
    * @param    view
    *           The view
    * @param    proxy
    *           The place proxy
    * @param    slot
    *           The slot
    * @param    placeManager
    *           The place manager
    */
   public BasePresenter(EventBus eventBus,
                        V view,
                        Proxy_ proxy,
                        GwtEvent.Type<RevealContentHandler<?>> slot,
                        PlaceManager placeManager)
   {
      super(eventBus, view, proxy, slot);
      
      this.placeManager = placeManager;
   }
   
   /**
    * Update browser's history and its url
    * 
    * @param    key
    *           The key parameter to update
    * @param    value
    *           The new value
    */
   protected void updateBrowserHistory(String key, String value)
   {
      PlaceRequest current = getPlaceManager().getCurrentPlaceRequest();
      Map<String, String> parameters = new HashMap<>(current.getParameterNames().size() + 1);
      current.getParameterNames().forEach(name -> {
         if (!name.equals(key))
         {
            parameters.put(name, current.getParameter(name, ""));
         }
      });
      PlaceRequest placeRequest = new PlaceRequest.Builder().nameToken(current.getNameToken())
               .with(parameters).with(key, value).build();
      getPlaceManager().updateHistory(placeRequest, true);
   }
   
   /**
    * Removes this parameter from the browser's history and its url.
    * 
    * @param    parameter
    *           The GET parameter to remove
    */
   protected void clearRequestParameter(String parameter)
   {
      PlaceRequest current = getPlaceManager().getCurrentPlaceRequest();
      Map<String, String> parameters = new HashMap<>(current.getParameterNames().size());
      current.getParameterNames().forEach(key -> {
         if (!key.equals(parameter))
         {
            parameters.put(key, current.getParameter(key, ""));
         }
      });
      PlaceRequest placeRequest = new PlaceRequest.Builder().nameToken(current.getNameToken())
               .with(parameters).build();
      getPlaceManager().updateHistory(placeRequest, true);
   }
   
   /**
    * Returns the GWTP place manager.
    * 
    * @return   The GWTP place manager
    */
   protected PlaceManager getPlaceManager()
   {
      return placeManager;
   }
   
   /**
    * Gets the current GET parameter value if it is found in the current url, otherwise returns
    * the provided value.
    * 
    * @param    key
    *           The GET parameter name
    * @param    defaultValue
    *           The provided default value
    * 
    * @return   The current GET parameter value if it is found in the current url, otherwise
    *           returns the provided value.
    */
   protected String getCurrentParameter(String key, String defaultValue)
   {
      PlaceRequest current = getPlaceManager().getCurrentPlaceRequest();
      return current.getParameter(key, defaultValue);
   }
   
   /**
    * Gets the current browser's query string.
    * 
    * @return   The current browser's query string
    */
   protected String getQueryString()
   {
      return getQueryString(getPlaceManager().getCurrentPlaceRequest());
   }
   
   /**
    * Gets the query string for the given request (the history or current one).
    * 
    * @param    current
    *           The given request
    * 
    * @return   The query string for the given request
    */
   protected String getQueryString(PlaceRequest current)
   {
      StringBuilder builder = new StringBuilder();
      current.getParameterNames().forEach(
         key ->
         {
            if (builder.length() > 0)
            {
               builder.append('&');
            }
            
            builder.append(key)
                   .append("=")
                   .append(URL.encodeQueryString(current.getParameter(key, "")));
         });
      
      return builder.toString();
   }
   
   /**
    * Gets the query parameters map for the given request (the history or current one).
    * 
    * @param    current
    *           The given request
    * 
    * @return   The query parameters map for the given request
    */
   protected Map<String, String> getQueryParametersMap(PlaceRequest current)
   {
      Map<String, String> builder = new LinkedHashMap<String, String>();
      current.getParameterNames().forEach(
         key ->
         {
            builder.put(key, current.getParameter(key, ""));
         });
      
      return builder;
   }

   /**
    * Sets the current search filter.
    * 
    * @param    value
    *           The current search template
    */
   public void setFilter(String value)
   {
      if (value == null || value.isEmpty())
      {
         filterExp = null;
         clearRequestParameter(FILTER);
      }
      else
      {
         filterExp = RegExp.compile(AdminHelper.wrapIntoCaseInsensitivePattern(value));
         updateBrowserHistory(FILTER, value);
      }
   }
   
   /**
    * Gets the current search template.
    * 
    * @return   The current search template
    */
   public String getCurrentFilter()
   {
      return getCurrentParameter(FILTER, "");
   }
   
   /**
    * Navigates to the given history or current request.
    * 
    * @param    request
    *           The given history or current request
    */
   protected void backTo(PlaceRequest request)
   {
      removeFromParentSlot();
      getPlaceManager().revealPlace(request);
   }
}