Re: Velocity vs. JSP: objective tests?

[Geir Magnusson Jr .]

On Friday, November 22, 2002, at 04:47 PM, Craig R. McClanahan wrote:

  #foreach $result in $results {
    <tr>
      <td>$result.ID</td>
      <td>$result.Name</td>
    </tr>
  }

actually, this is syntax is almost completely wrong.  :)

a more fitting example would be:
#foreach( $result in $sometool.results )
<tr>
    <td>$result.ID</td>
    <td>$result.Name</td>
</tr>
#end

velocity and it's supporting tools are evolving too. :-)

Sorry ... I was following an example from a published article (don't
remember where) so I presume that it (at least) *used* to be correct :-0.

I think you are confusing webmacro syntax and velocity syntax. Velocity never supported the lack of parens in the foreach, and never supported { or } as block delimiters.

...

* Velocity advocates used to argue that using Velocity was safer
  because it restricted what a page designer could do to calling
  getter methods.  This was never a completely true argument
  (how do *you* know that the getter method of the beans you are
  calling doesn't mutate something?), but it's been pretty much
  eliminated by the fact that you can call arbitrary methods
  in Velocity.

yes, it is possible to design badly even in Velocity, but perhaps we could
agree it's at least harder in Velocity to do so.

Harder != Impossible.

This used to be the most compelling pro-Velocity argument, IMHO,
especially for people managing large content-rich web sites where you
really don't want a page author to be able to totally screw things up by
executing arbitarry code. General method calls are very convenient (and
they're in JSP 2.0's version of the expression language as well :-), but
there is no longer a difference in this regard.

Is that true?  I didn't think that general method calls were available.

...

There was an interesting article on onjava.com about a project to
implement a simple blogger app that used both Struts and Velocity:

http://www.onjava.com/pub/a/onjava/2002/04/17/wblogosj2ee.html

I was particularly struck by the following snippet of Velocity code:

$macros.showNavBar(true)

which builds part of the UI by rendering the navigation bar. I don't know
about you, but that looks an awful lot like a scriptlet equivalent:

<% macros.showNavBar(true); %>

to me :-).

yeah, no offense intended to David Johnson, but that's a really poor way to
use Velocity. it looks as though that method is intended to spit out some
HTML hardcoded into whatever $macros is or some such thing. the HTML
shouldn't come from the java, it should be in the template to begin with, or
at least defined the global Velocimacro library. that way the code could
just be:

#showNavBar( true)

Fine ... still looks like a scriptlet to me :-).

Which was another feature introduced to JSP after Velocity? It's good when the standard follows. ;->

Seriously - What Nathan was saying had nothing to do with syntax - he's suggesting that something that generates HTML output shouldn't be written in Java, but rather by a designer in the designers environment, either JSP or Velocity or whatever.

So #shownavbar( true ) is a Velocimacro, a little parameterized Velocity template. $macros.showNavBar(true) might be the same thing - invoking the method showNavBar(Boolean) that uses velocity inside to render templates/macros. In that case, I think that's cool - because then the output doesn't really come from Java - it's still in velocity.

geir

-- Geir Magnusson Jr 203-355-2219(w)
Adeptra, Inc. 203-247-1713(m)
[EMAIL PROTECTED]


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