How can I show part of my text in my template?

[Elahe Shafie]

Hi Friends,
I like to show just first 20 character of my text in my template, since desc in about 100 characters and I don't want to show all could you please tell me how can I do it?
<td class='trow'>${item.desc}</td>
Many thnaks for your help,
Elahe

[Mike Curwen]

It's easier than you think

${item.desc.substring(0,20)} should give you the first 20 characters.

Just remember that 'item.desc' is really calling the ' String getDescription() ' method of the ' item ' object. Since you are getting a String, you should be able to use any of the String methods on this object.

An alternate way of doing this is to have your backing class (item) have a second method, something like:

public String getShortDescription() {
   return this.description.substring(0,20);
}

Then in VTL call it like:
${item.shortDescription}

[Elahe Shafie]

Mike thank you soooooooo much for your answer.
So based on your suggestion I like to have a class
Tool1 and it's function is getting the text and the number and then get substry of that text with that number like my case the number is 20...so
Could you please help me and see Tool1 class functions based on your idea?

package com.srs.veltools;
public class Tool1 {
  public String getShortDescription(String strLong, int nMax)
  {
    String strShort = this.description.substring(0,20);
    return strShort;
  }
}//eoc

and then I can call this method in my template like:
$item.shortLen(${item.description},20)

[Elahe Shafie]

Sorry I can call this method in my template like:
$item.getShortDescription((${item.description},20)

[Mike Curwen]

Hi elahe,
I wouldn't do it the way you are proposing. The method signature for your getShortDescription doesn't need that first string. The class containing this method already contains the string you are sending in. This is easy to see when you try to call it. You have item.getShortDescription, and then send it item.description. 'item' already *has* that description string.

public class Tool1 {
  private String description;
 
  public String getDescription() {
     return this.description; 
  }
 
  public String getShortDescription() {
     return getShortDescription(20);
  }
 
  public String getShortDescription(int len) {
     return this.description.substring(0,len);
  }
 
 
  //more getters here...
 
}

Now in your velocity servlet, you'd populate the values of an instance of this Tool1 class from a database, or with hard-coded values, and place it into the velocity context...

Tool1 item = new Tool1();
item.add("description" , "Long description for the particular instance of tool");
 
//place in velocity context...
ctx.put("item", item);

And now in your velocity template, you can use any of the methods of Tool1 on your 'item' object.

{$item.description}
{$item.shortDescription}
{$item.getShortDescription(10)}

If I've misunderstood, and you were meaning Tool1 class to be a utility class of some sort, to be re-used wherever... I think for this exact case, you are re-inventing the wheel. The substring method on java.lang.String does everything your 'getShortDescription' method does.. why wrap it?

[Elahe Shafie]

Mike thanks a lot for your big help and let post my clas based on your idea and mine for you to confim with you:
Here is Tool1 class:

package com.srs.veltools;
/**
 *
 * @author  ES
 * @version
 */
public class Tool1 {
  public String getShortDescription(String strLong, int nMax)
  {
    String strShort = strLong.substring(0,nMax);
    return strShort;
  }
}//eoc

and im my template:

...
 <td class='trow'>$tool1.getshortDesc(${item.desc},50)</td>
...

and in my servlet:

...
ctx.put("tool1", oTool );      
...

and I just don't know where I should put
Tool1 oTool = new Tool1() in my servlet! here is my servlet
Your input is a big help for me,
Elahe

package com.srs.bugtrack;
import org.apache.velocity.Template;
import org.apache.velocity.context.Context;
import org.apache.velocity.servlet.VelocityServlet;
import org.apache.velocity.app.Velocity;
import org.apache.velocity.exception.ResourceNotFoundException;
import org.apache.velocity.exception.ParseErrorException;
import java.io.*;
import java.util.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.text.SimpleDateFormat;
/**
 */
public class BugsList extends BaseServlet {
  
  static private final boolean debug = true;
  protected String strLinkAction;
  /************/
  public void init(ServletConfig config)
  throws ServletException
  {
    super.init(config);
    
    ServletContext sctx = config.getServletContext();
    strLinkAction = getInitParameter("linkaction");
  }
  /*************/
  
  public Template handleRequest( HttpServletRequest req,
  HttpServletResponse res,
  Context ctx )
  
  throws IOException, ServletException
  {
    Template templateRet = null;
    
    /* first do standard additions to context */
    handleRequestBase( req, res, ctx );
    ctx.put( "linkaction", strLinkAction );
        /* set up some data to put into the context */
    
     try
     {
      /* - 1 ------------------------ */
       String strX;
     
       /* This will be a link back to the servlet containing
       only the select parameters.  Any order parameters
       are removed. For example, if the request came in as
       link1?dev=ms&status=open
       this string will be
       dev=ms&status=open
       This text is placed back into the context so that
       following pages can use the same select again. */
      String strSelectParam = null;
      
      /* This will be an SQL order clause or null */
      String strOrder = null;
      
      /* This will be an SQL where clause or null */
      String strWhere = null;
      
      /* This will be the user readable version of the
       where clause to be put in the HTML output */
      String strSelectText = null;
    
     /*************************/
      /* if the request has any selection parameters
       construct a sql where clause */
      strX = req.getParameter( "dev" );
      if ( strX != null ) {
        strWhere = "u.name='"+strX +"'";
        strSelectText = "for "+ strX;
        strSelectParam = "dev="+strX;
      }
      
      strX = req.getParameter( "status" );
      if ( strX != null ) {
        if ( null!=strWhere ) {
          strWhere += " and s.text='"+strX+"'";
          strSelectText += " and where status is "+strX;
          strSelectParam += "&status="+strX;
        }
        else {
          strWhere = "s.text='"+strX+"'";
          strSelectText = "where status is "+strX;
          strSelectParam = "status="+strX;
        }
      }
      
      strX = req.getParameter( "bugNumber" );
      if ( strX != null ) {
        if( null!=strWhere ) {
          strWhere += " and b.bugNumber='"+strX+"'";
          strSelectText += " and where bugNumber is "+strX;
          strSelectParam += "&bugNumber="+strX;
        }
        else {
          strWhere = "b.bugNumber='"+strX+"'";
          strSelectText = "where bugNumber is "+strX;
          strSelectParam = "bugNumber="+strX;
        }
      }
      
      /* The table title will change to reflect any selection
       made by the select parameter
       If no where clause was constructed, default to the full
       title. */
      if ( null==strWhere ) {
        ctx.put( "tabletitle", "List of all entries" );
      }
      else {
        ctx.put( "tabletitle", "List of entries" );
        ctx.put( "subset", strSelectText );
        ctx.put( "selparam", strSelectParam );
      }
      
      
      /* If an "order" parameter was included, use it.
       Default is by number */
      strX = req.getParameter( "order" );
      if ( strX != null ) {
        if ( 0 == strX.compareToIgnoreCase( "status" ) ) {
          strOrder = "s.text";
        }
        else if ( 0 == strX.compareToIgnoreCase( "desc" ) ) {
          strOrder = "bdesc";
        }
        else if ( 0 == strX.compareToIgnoreCase( "sdate" ) ) {
          strOrder = "submittedDate";
        }
        else if ( 0 == strX.compareToIgnoreCase( "contact" ) ) {
          strOrder = "contact";
        }
        else if ( 0 == strX.compareToIgnoreCase( "assign" ) ) {
          strOrder = "name";
        }
        else {
          strOrder = "bugNumber";
        }
      }
      else {
        strOrder = "bugNumber";
      }
      
      /* -- 2 --------------------------------------*/
      vbug = model.getBugs(strWhere,strOrder);
        
     /* -- 3 --------------------------------------*/
      
      /* Once the vector has been successfully filled with data
       add it to the context.  If we fail, before here, there will
       not be an object in the template */
      ctx.put("theList", vbug );
      ctx.put("tool1", oTool );      
      
      templateRet = finishRequest();
    }
    catch ( SQLException x ) {
      ctx.put( "errorsql", "unknown" );
      templateRet = doErrorPage( ctx, x );
    }
    catch ( Exception x ) {
      templateRet = doErrorPage( ctx, x );
    }
    return templateRet;
  }
 } // eoc

[Mike Curwen]

Hi Elahe,

Now that I see more of your code, I can tell a bit more. Your vbug vector must contain hashtables, one for each bug? Or something like that.. maybe it's your own 'bug' object.

If it is, I still think the best place for the 'getShortDescription' method is in that object. (in the 'bug' class not the Tool1 class at all). And access it like I showed earlier

#foreach ($bug in $bugs)
  <li>{$bug.shortDescription}</li>

Otherwise, I would make the method static, and you needn't place an instance of the Tool1 class into the context at all. Hopefully that would work, I don't have Velocity handy right now. Call would look like:

 {$Tool1.getShort($item.descr)} 

I'm half certain it won't. So where you have it in your code is appropriate (way down at the bottom there)

[Elahe Shafie]

Mike,
Many thanks for following up with me...now it is working but I don't know why this error happends right after showing half of the Bugs list in template:
Could you please give me your advice?
Many thanks,
Elahe
--------------
VelocityServlet : Error processing the template
org.apache.velocity.exception.MethodInvocationException: Invocation of method 'getShortDesc' in class com.srs.veltools.Tool1 threw exception class java.lang.StringIndexOutOfBoundsException : String index out of range: 20
org.apache.velocity.exception.MethodInvocationException: Invocation of method 'getShortDesc' in class com.srs.veltools.Tool1 threw exception class java.lang.StringIndexOutOfBoundsException : String index out of range: 20 at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:308) at

[Elahe Shafie]

Mike,
It has been solved this way...
Many thanks for your help and support,
Elahe

package com.srs.veltools;
/**
 *
 * @author  ES
 * @version
 */
public class Tool1 {
  public String getShortDesc(String strLong, int nMax)
  {
    if ( nMax >= strLong.length() )
    {
      //is shorter than substring length, but that's OK!
      return strLong;
    }
    else
    {
      return strLong.substring(0,nMax);
    }
  }
}//eoc