com.draagon.meta.web.view.html.HotLinkView Maven / Gradle / Ivy

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/*
 * Copyright 2003 Draagon Software LLC. All Rights Reserved.
 *
 * This software is the proprietary information of Draagon Software LLC.
 * Use is subject to license terms.
 */
package com.draagon.meta.web.view.html;

import com.draagon.meta.*;
import com.draagon.meta.web.view.ViewHelper;
import com.draagon.meta.web.view.WebView;
import com.draagon.meta.web.view.WebViewException;
import com.draagon.util.web.URLConstructor;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.PageContext;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

/**
 * Renders a HotLink view.
 * 
 * 
The possible MetaView attributes are the following:
 * 

 * url - The URL pattern to use for the link; it can contain ${} references which refer to the field's to insert the value from
 * linkClass - (Optional) The class to assign the  html tag

 * 

 */
public class HotLinkView extends HtmlView {
  private static Log log = LogFactory.getLog(HotLinkView.class);

  public final static String ATTR_LINKCLASS = "linkClass";
  public final static String ATTR_URL = "url";

  public HotLinkView() {
  }

  /**
   * Retrieves the attribute options expected for this class
   */
  public Collection getAttributeOptions() {
    ArrayList al = new ArrayList();
    al.add(new AttributeOption(ATTR_LINKCLASS, String.class, false, "HTML style class for the link"));
    al.add(new AttributeOption(ATTR_URL, String.class, true, "The url for the hotlink"));
    al.add(super.getAttributeOptions());
    return al;
  }

  public void doView(PageContext page, Object o, String label, int mode, Map params)
      throws MetaException {
    MetaField mf = getMetaField(o);
    //MetaClass mc = mf.getMetaClass();

    try {
      if (mode == READ)
        doHotLinkView(page, o, label, mode, params);
    }
    catch (IOException e) {
      log.error("Error displaying HotLinkView for field [" + mf + "] with mode [" + modeToString(mode) + "]", e);
      throw new WebViewException("Cannot render HotLinkView for field [" + mf + "] in mode [" + modeToString(mode) + "]: " + e.getMessage(), e);
    }
  }

  /**
   * Retrieves the stylesheet class to use for the anchor html tag
   */
  public String getLinkClass(Map params) {
    String def = null;
    try {
      def = (String) getAttribute("linkClass");
    }
    catch (MetaAttributeNotFoundException e) {
    }

    return ViewHelper.getStringParam(params, "linkClass", def);
  }

  /**
   * Renders a hotlink view
   */
  protected void doHotLinkView(PageContext page, Object o, String label, int mode, Map params)
      throws IOException, MetaException {
    String link = createLink(page, o, mode, params);
    String val = getMetaField(o).getString(o);

    if (link == null && val == null) return;

    if ( !hasAttribute( "viewRef" ))
    	HtmlViewHelper.drawLink(page, link, val, getLinkClass(params), params);
    else
    {
    	String viewRef = (String) getAttribute( "viewRef" );

    	WebView mv = (WebView) getMetaField(o).getView( viewRef );

	    String linkClass = getLinkClass(params);

	    JspWriter out = page.getOut();

	    // if ( text == null ) text = " ";

	    if ( link != null )
	    {
	      out.print("");
	    }

	    mv.doView( page, o, mode, params );
	    // out.print( text );

	    if ( link != null ) out.print("");
    }
  }

  /**
   * Creates the hotlink by reading the url attribute and inserting the field values
   */
  protected String createLink(PageContext page, Object o, int mode, Map params)
      throws MetaException {
    String url = (String) getAttribute("url");

    if (url == null)
      throw new MetaException("No 'url' attribute found for view [" + getName() + "] in field [" + getMetaField(o) + "]");

    // If the URL starts with a "/" then prepend the Context Path
    if (url.startsWith("/")) {
      String context = ((HttpServletRequest) page.getRequest()).getContextPath();
      url = context + url;
    }

    MetaClass mc = MetaClassLoader.findMetaClass(o);

    HashMap map = new HashMap();

    // Extract the possible fields for insertion
    int i = 0;
    while (true) {
      int j = url.indexOf("${", i);
      if (j >= 0) {
        int k = url.indexOf("}", j);
        if (k >= 0) {
          // Increment to the next search segment
          i = k + 1;

          // Get the MetaField
          String name = url.substring(j + 2, k);
          MetaField mf = mc.getMetaField(name);

          //get value out of data object using
          String value = mf.getString(o);
          if (value == null) value = "";

          // Add the the HashMap
          map.put(name, value);

          continue;
        }
      }

      break;
    }//while

    // Construct the HotLink URL and return it
    return URLConstructor.constructURL(url, map);
  }

  /**
   * Retrieve the value for the field and place it into the object
   */
  @Override
  public void getValue(HttpServletRequest request, Object o, String label )
      throws MetaException {
    throw new MetaException("This is a read only view");
  }
}