How to access an array [Possibly a really stupid question]

["Henning P. Schmiedehausen" <hp...@intermeta.de>]

Hi,

I've played with Velocity a little and now I want to use it in a small
application. Basically this application creates a context with a
callback method and a row counter. The template should create a table
from it. The table should have (as this is considered "relevant" by
the UI designers) alternating colors for its rows.

I had the following pseudocode in mind:

--- cut ---
#set ( $color = [ "color1", "color2" ] )
#set ( $colsel = 0 )

<TABLE>
#foreach ($row in $tbl.getRows())
  <TR BGCOLOR="$color[$colsel]">
   <TD>$tbl.getData($row)</TD>
  </TR>
#set ($colsel = 1 - $colsel)
#end
</TABLE>
--- cut ---

... and then I noticed that there seems to be no way to access an
array element by index. =:-( The only way that I found to access an
array element is with foreach.

So I had to resort to the following ugly beast:

--- cut ---
#macro( bgcol $colsel $c1 $c2 )
#if ($colsel == 0)
BGCOLOR="$c1"
#else
BGCOLOR="$c2"
#end
#end

#set ($colsel = 1)
#set ($c1="color1")
#set ($c2="color2")

#foreach ( $row in $tbl.getRows() )
  <TR #bgcol($colsel $c1 $c2)>
   <TD>$tbl.getData($row)</TD>
  </TR>
#set ($colsel = 1 - $colsel)
#end
</TABLE>
--- cut ---


Ugh. Horrors. Did I miss something? How can I access a certain element
in an object array by index?

	Regards
		Henning

-- 
Dipl.-Inf. (Univ.) Henning P. Schmiedehausen       -- Geschaeftsfuehrer
INTERMETA - Gesellschaft fuer Mehrwertdienste mbH     hps@intermeta.de

Am Schwabachgrund 22  Fon.: 09131 / 50654-0   info@intermeta.de
D-91054 Buckenhof     Fax.: 09131 / 50654-20   

Re: How to access an array [Possibly a really stupid question]

[Jason van Zyl <jv...@apache.org>]

"Henning P. Schmiedehausen" wrote:
> 
> Hi,
> 
> I've played with Velocity a little and now I want to use it in a small
> application. Basically this application creates a context with a
> callback method and a row counter. The template should create a table
> from it. The table should have (as this is considered "relevant" by
> the UI designers) alternating colors for its rows.
> 
> I had the following pseudocode in mind:
> 
> --- cut ---
> #set ( $color = [ "color1", "color2" ] )
> #set ( $colsel = 0 )
> 
> <TABLE>
> #foreach ($row in $tbl.getRows())
>   <TR BGCOLOR="$color[$colsel]">
>    <TD>$tbl.getData($row)</TD>
>   </TR>
> #set ($colsel = 1 - $colsel)
> #end
> </TABLE>

Fortunately for you the [..] operator makes an ArrayList
and not an array :-) I haven't tested this but you can
probably use this:

<TABLE>
#foreach ($row in $tbl.getRows())
  <TR BGCOLOR="$color.get($colsel)">
   <TD>$tbl.getData($row)</TD>
  </TR>
#set ($colsel = 1 - $colsel)
#end
</TABLE>



> --- cut ---
> 
> ... and then I noticed that there seems to be no way to access an
> array element by index. =:-( The only way that I found to access an
> array element is with foreach.
> 
> So I had to resort to the following ugly beast:
> 
> --- cut ---
> #macro( bgcol $colsel $c1 $c2 )
> #if ($colsel == 0)
> BGCOLOR="$c1"
> #else
> BGCOLOR="$c2"
> #end
> #end
> 
> #set ($colsel = 1)
> #set ($c1="color1")
> #set ($c2="color2")
> 
> #foreach ( $row in $tbl.getRows() )
>   <TR #bgcol($colsel $c1 $c2)>
>    <TD>$tbl.getData($row)</TD>
>   </TR>
> #set ($colsel = 1 - $colsel)
> #end
> </TABLE>
> --- cut ---
> 
> Ugh. Horrors. Did I miss something? How can I access a certain element
> in an object array by index?
> 
>         Regards
>                 Henning
> 
> --
> Dipl.-Inf. (Univ.) Henning P. Schmiedehausen       -- Geschaeftsfuehrer
> INTERMETA - Gesellschaft fuer Mehrwertdienste mbH     hps@intermeta.de
> 
> Am Schwabachgrund 22  Fon.: 09131 / 50654-0   info@intermeta.de
> D-91054 Buckenhof     Fax.: 09131 / 50654-20

-- 
jvz.

Jason van Zyl
jvanzyl@apache.org

http://jakarta.apache.org/velocity
http://jakarta.apache.org/turbine
http://tambora.zenplex.org