selectdatasource_engine.java

java 写的一个新闻发布系统

//
//                                   ____.
//                       __/\ ______|    |__/\.     _______
//            __   .____|    |       \   |    +----+       \
//    _______|  /--|    |    |    -   \  _    |    :    -   \_________
//   \\______: :---|    :    :           |    :    |         \________>
//           |__\---\_____________:______:    :____|____:_____\
//                                      /_____|
//
//                 . . . i n   j a h i a   w e   t r u s t . . .
//

//
//  SelectDataSource_Engine
//  EV      03.12.2000
//
//  getInstance()
//  authoriseRender()
//  renderLink()
//  needsJahiaData()
//  handleActions()
//

package org.jahia.engines.selectdatasource;

import java.io.*;                       // PrintWriter
import java.util.*;                     // Enumeration
import java.net.*;                      // URLEncoder

import org.jahia.utils.*;           // JahiaConsole
import org.jahia.data.*;            // JahiaData
import org.jahia.data.fields.*;     // JahiaField
import org.jahia.params.*;          // ParamBean
import org.jahia.engines.*;         // JahiaEngine interface, EngineParams
import org.jahia.exceptions.JahiaException;


public class SelectDataSource_Engine implements JahiaEngine {

    private static  SelectDataSource_Engine theObject   = null;
    private         String                  engineName  = "selectdatasource";



    /***
        * constructor
        * EV    03.12.2000
        *
        */
    private SelectDataSource_Engine()
    {
        // JahiaConsole.println( "Engine", "***** Starting SelectDataSource Engine *****" );
    } // end constructor



    /***
        * getInstance
        * EV    03.12.2000
        *
        */
    public static synchronized SelectDataSource_Engine getInstance()
    {
        if (theObject == null) {
            theObject = new SelectDataSource_Engine();
        }
        return theObject;
    } // end getInstance



    /***
        * authoriseRender
        * EV    03.12.2000
        *
        */
    public boolean authoriseRender( ParamBean jParams )
    {
        return (jParams.getOperationMode() == jParams.EDIT);
    } // end authoriseRender



    /***
        * renderLink
        * EV    03.12.2000
        *
        */
    public String renderLink( ParamBean jParams, Object theObj )
    throws JahiaException
    {
        JahiaField   theField    = (JahiaField) theObj;
        String params = "";
//        params += "&mode=displaywindow";
        params += "?mode=displaywindow";
        params += "&fid=" + theField.getID();
        return jParams.composeEngineUrl( engineName, params );
    } // end renderLink



    /***
        * needsJahiaData
        * EV    03.12.2000
        *
        */
    public boolean needsJahiaData( ParamBean jParams )
    {
        return false;
    } // end needsJahiaData



    /***
        * handleActions
        * EV    03.12.2000
        *
        */
    public void handleActions( ParamBean jParams, JahiaData jData )
    throws JahiaException
    {
        String mode     = jParams.getRequest().getParameter( "mode" );
        String ipAddr   = jParams.getRequest().getRemoteAddr();
        if (mode != null) {
            if (mode.equals("displaywindow")) {
                JahiaConsole.println( "SelectDataSource_Engine", ipAddr + " is displaying SelectDataSource Window"  );
                displayFormWindow( jParams );
            } else if (mode.equals("processform")) {
                JahiaConsole.println( "SelectDataSource_Engine", ipAddr + " is processing SelectDataSource Form"  );
                processForm( jParams );
            }
        }
    } // end handleAction



    /***
        * displayFormWindow()
        * EV    03.12.2000
        *
        */
    public void displayFormWindow( ParamBean jParams )
    throws JahiaException
    {
        String html         = "";

        String urlParams    = "";
        urlParams           += "&mode=processform";
        String theUrl       = jParams.composeEngineUrl( engineName, urlParams );

        html += "<center><table border=\"0\" width=\"90%\"><tr>\n";
        html += "<td width=\"100%\" colspan=\"2\" bgcolor=\"#333333\">\n";
        html += "<font face=\"arial\" size=\"2\">Please enter datasource id :</font>\n";
        html += "</td></tr>\n";
        html += "<tr><td width\"20%\" valign=\"top\">&nbsp;</td>\n";
        html += "<td width=\"80%\">";
        html += "<form method=\"POST\" action=\"" + theUrl + "\">\n";
        html += "<input type=\"text\" name=\"datasource_url\" size=\"20\" maxlenght=\"250\" value=\"http://\">";
        html += "</form>\n";
        html += "</td></tr></table>\n";

        EngineRenderer.getInstance().render( jParams, engineName, html );
    }
    // end displayFormWindow




    /***
        * processForm()
        * EV    20.11.2000
        *
        */
    public void processForm( ParamBean jParams )
    throws JahiaException
    {
        String dsUrl = "";
        try {
            dsUrl = jParams.getRequest().getParameter( "datasource_url" );

            PrintWriter out = jParams.getResponse().getWriter();
            jParams.getResponse().setContentType( "text/html" );
            out.println( "<center> Computing values... </center>" );

            String encodedUrl = URLEncoder.encode( dsUrl );
            out.println( "<script language=\"javascript\" src=\"" + jParams.settings().getJsHttpPath() + "\">" );
            out.println( "</script>" );
            out.println( "<script language=\"javascript\">" );
            if (!dsUrl.equals("")) {
                out.println( "  CloseJahiaWindow('&engine_params=dsurl" + EngineParams.VALUE_TOKEN + encodedUrl + "');" );
            } else {
                out.println( "  CloseJahiaWindow();" );
            }
            out.println( "</script>" );

        } catch (IOException ie) {
            String errorMsg = "Error while handling the SelectDataSource Window : " + ie.getMessage() + " -> BAILING OUT";
            JahiaConsole.println( "SelectDataSource_Engine", errorMsg );
            throw new JahiaException(   "Error while handling a Jahia window's content",
                                        errorMsg, JahiaException.DATA_ERROR, JahiaException.CRITICAL );
        }
    }
    // end processForm



} // end SelectDataSource_Engine