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Hi,
Ok,
this I can understand. If tags (somehow) can be easier to use for non Java
programmers, assuming that they won't have to write complicated predicates, or
otherwise the whole of Java will have to be rewritten with XML syntax. I guess
that's why I think specific conditional tags (like testing request parameters,
DB values, bean properties etc..) make more sense. Code
like:
<lib:if>
<lib:condition>
<lib:or>
<req:param name="type" value="car"/>
<req:param name="type" value="plane"/>
</lib:or>
</lib:condition>
<lib:then>
....
</lib:then>
</lib:if>
would
be horrible ;)
Thanks
for your responses,
Borislav
The other issue
here is programmer-vs.-designer people who might work on a
page.
I'd rather give a
designer something that looked like HTML, something they're
used
to, than have to
introduce any of several Java programming constructs.
That said, I have
a heavy mix of both custom tags and scriptlets on our site
because
a) I'm also one of
the designers and I can get away with it and b) sometimes it's
quicker
to do a scriptlet
than generalize functionality into a tag.
Dave
--
Dave Newton, [EMAIL PROTECTED]
Some people, myself included, for the sake of uniformity and design,
would like to maximize the usage of XML-like JSP tags. I would
love if all my server-side java code could be either packed away behind
beans, or hidden behind XML-like JSP tags. I think all of us would
love this also, though sometimes this is not feasible.
Brett
-----Original Message-----
From: Borislav
Iordanov
Sent: 2001-06-06 (수) 오후 8:55
To:
[EMAIL PROTECTED]
Cc:
Subject: RE: RE:
If/Else tag?
Hi,
I'm just wondering, what's wrong with
scriplets. I'm really failing to find any value in a tag "replacement" of
the usual and natural Java if statement. It seems to me that the useful
conditional tags are the ones with some predefined and parametrizable (in
a simple way) conditions, like the <req:ifParameter name="..."
value="..."> and even then.... what's the point? Is it just that for
you something like:
<utils:if predicate='<%= ...
%>'>
</utils:if>
looks better than
<% if
(....) %>
<% } %>
Just asking, because I'm really
wondering whether there's some inherent advantage in having tags instead
of scriplets, or it's simply a matter of personal taste and some prefer
writing tags.
Borislav
-----Original Message-----
From:
Amos Shapira [mailto:[EMAIL PROTECTED]]
Sent:
Tuesday, June 05, 2001 2:12 AM
To:
'[EMAIL PROTECTED]'
Subject: RE: RE: If/Else
tag?
Sorry, but if the purpose of taglibs is, among other
things,
to make the code more readable and maintainable then
such
tricks are not helping this goal, IMHO.
Also - what about
nested "if/else"?
Starts to look like old-fasioned basic to me (the
one on
Genie II and XT ROM Basic, not Visual Basic) :-)
I'll
stick to scriptlets for now, as much as I'd like to
avoid
them.
Cheers,
--Amos
-----Original
Message-----
From: Mikko Kurki-Suonio [mailto:[EMAIL PROTECTED]]
Sent:
Tuesday, June 05, 2001 8:45 AM
To:
'[EMAIL PROTECTED]'
Subject: Re: RE: If/Else
tag?
On Tue, 5 Jun 2001, [utf-8] Amos Shapira
wrote:
> I considered this but:
>
> 1. It's
not always clear (especially if the predicate is complex) that
the
> "else" predicate is the opposite of
the "if".
> 2. Worse - whenever you change the "if" predicate you
have to remember
> to change the "else"
too. Very unmaintainable over time.
> 3. It's not clear that
the two are actually related to each other.
> 4. You have to
consider side-effects (as you said - if the "if"
changes
> "x", but also if the evaluation of
"x" has side effects).
Simple. Just set a DIFFERENT flag variable
whenever you trip the "real IF"
and test the _flag_ for the
"ELSE".
In pseudocode:
x_else_flag = true;
if x then
x_else_flag = false; blah blah blah;
if x_else_flag then
do_the_else_thingy;
//Mikko
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