Re: Break or Continue in a whiel loop
"Marcello H" <[email protected]> Thu, 26 Oct 2006 12:59:21 +0200
| Newsgroups | gmane.comp.java.webmacro.user |
|---|---|
| Message-ID | <[email protected]> |
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I don't understand this.
There has been a while loop, with some extra special features, written by
Mike Weerdenburg.
He did send it by mail to the group, since he was unable to put in cvs at
that time.
But somebody did check it in (perhaps I did, I don't know).
But I'm preety sure it works, since I use it a lot.
If you grab the lastest code out of cvs, you will see the while directoive
in the directive directory.
/**
* Syntax: #while (condition) [limit (int)] { block } WhileDirective
implements a WebMacro directive for an while
* control structure. If you use it without the limit option than it stops
after 1000000 loops!
* Use a limit value < 0 to create a loop without a limit, this could hang
your template!
* Introduced at release 2.0 as an experimental directive.
*/
Works as should!
Greeting form Holland,
and good luck
Marcel
2006/10/19, Shane Farmer <[email protected]>:
>
> Thanks Keats for the words of wisdome. I think that has given me
> everything I need to finish it off.
>
> The main reason for coding a while loop was to help another developer out.
> Maybe #count would have worked better for him.
>
> Shane
>
> On 10/19/06, Keats Kirsch <[email protected]> wrote:
> >
> > The directive code looks pretty clean, but I'd question the need for
> > it. We've discussed a #while directive many times over the years, and I
> >
> > have yet to see a use-case that couldn't be handled pretty well by
> > #foreach or #count. The general feeling was always that #while is too
> > dangerous because it makes it too easy for a template designer to
> > introduce infinite loops.
> >
> > However I think a #break directive or subdirective might be useful.
> > One approach might be to add an option to the directive, like:
> >
> > #foreach $var in $collection breakon $break {
> > #if ($var = "Bad") { #set $break = true }
> > }
> >
> > Then the directive could just check the value of the break variable.
> >
> > The problem with a break directive is that you would have to deal with
> > nested loops. This could be handled by using labels, like in Java.
> >
> > #foreach $list in $collection label "outerloop" {
> > #foreach $item in $list {
> > #if ($item = "Bad") { #break "outerloop" }
> > }
> > }
> >
> > This would be harder than the first option, and not any better really
> > IMHO.
> >
> > I don't think #continue would be useful. It would be difficult to code
> > and you can always use an #if instead, which is cleaner anyway.
> >
> > Keats
> >
> > Shane Farmer wrote:
> > > Hi All,
> > >
> > > I have been looking around for a while loop to no avail. As such I
> > > have implimented a very basic while loop directive. I am using an
> > > older version of WM (1.0 or 1.1) and was wondering if it possible to
> > > create 2 subdirectives, break and continue, and if anyone would have
> > > some pointers on how to go about doing this.
> > >
> > > The code is _very_ basic ATM and simply loops while ever the
> > > conditional arg is true and evaluates [block.write(...)] on the block
> > arg.
> > >
> > > Im am all ears for better design startegies for this directive as
> > well.
> > >
> > > Thanks in advance
> > > Shane
> > >
> > ------------------------------------------------------------------------
> > >
> > >
> > -------------------------------------------------------------------------
> > > Using Tomcat but need to do more? Need to support web services,
> > security?
> > > Get stuff done quickly with pre-integrated technology to make your job
> > easier
> > > Download IBM WebSphere Application Server v.1.0.1 based on Apache
> > Geronimo
> > > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642
> >
> > >
> > ------------------------------------------------------------------------
> > >
> > > _______________________________________________
> > > Webmacro-user mailing list
> > > [email protected]
> > > https://lists.sourceforge.net/lists/listinfo/webmacro-user
> > >
> >
> >
> >
> > -------------------------------------------------------------------------
> >
> > Using Tomcat but need to do more? Need to support web services,
> > security?
> > Get stuff done quickly with pre-integrated technology to make your job
> > easier
> > Download IBM WebSphere Application Server v.1.0.1 based on Apache
> > Geronimo
> > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642
> > _______________________________________________
> > Webmacro-user mailing list
> > [email protected]
> > https://lists.sourceforge.net/lists/listinfo/webmacro-user
> >
>
>
> -------------------------------------------------------------------------
> Using Tomcat but need to do more? Need to support web services, security?
> Get stuff done quickly with pre-integrated technology to make your job
> easier
> Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo
> http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642
>
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>
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I don't understand this.<br>There has been a while loop, with some extra special features, written by Mike Weerdenburg.<br><br>He did send it by mail to the group, since he was unable to put in cvs at that time.<br>But somebody did check it in (perhaps I did, I don't know).
<br>But I'm preety sure it works, since I use it a lot.<br><br>If you grab the lastest code out of cvs, you will see the while directoive in the directive directory.<br><br>/**<br> * Syntax: #while (condition) [limit (int)] { block } WhileDirective implements a WebMacro directive for an while
<br> * control structure. If you use it without the limit option than it stops after 1000000 loops!<br> * Use a limit value < 0 to create a loop without a limit, this could hang your template!<br> * Introduced at release
2.0 as an experimental directive.<br> */<br><br>Works as should!<br><br>Greeting form Holland,<br>and good luck<br><br>Marcel<br><br><br><br><br><br><div><span class="gmail_quote">2006/10/19, Shane Farmer <<a href="mailto:[email protected]">
[email protected]</a>>:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div>Thanks Keats for the words of wisdome. I think that has given me everything I need to finish it off.
</div>
<div> </div>
<div>The main reason for coding a while loop was to help another developer out. Maybe #count would have worked better for him.</div><span class="sg">
<div> </div>
<div>Shane<br> </div></span><div><span class="e" id="q_10e5daeb6c0baf85_2">
<div><span class="gmail_quote">On 10/19/06, <b class="gmail_sendername">Keats Kirsch</b> <<a href="mailto:[email protected]" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">[email protected]</a>> wrote:
</span>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0px 0px 0px 0.8ex; padding-left: 1ex;">The directive code looks pretty clean, but I'd question the need for<br>it. We've discussed a #while directive many times over the years, and I
<br>have yet to see a use-case that couldn't be handled pretty well by<br>#foreach or #count. The general feeling was always that #while is too<br>dangerous because it makes it too easy for a template designer to<br>introduce infinite loops.
<br><br>However I think a #break directive or subdirective might be useful.<br>One approach might be to add an option to the directive, like:<br><br>#foreach $var in $collection breakon $break {<br>#if ($var = "Bad") { #set $break = true }
<br>}<br><br>Then the directive could just check the value of the break variable.<br><br>The problem with a break directive is that you would have to deal with<br>nested loops. This could be handled by using labels, like in Java.
<br><br>#foreach $list in $collection label "outerloop" {<br> #foreach $item in $list {<br> #if ($item = "Bad") { #break "outerloop" }<br> }<br>}<br><br>This would be harder than the first option, and not any better really IMHO.
<br><br>I don't think #continue would be useful. It would be difficult to code<br>and you can always use an #if instead, which is cleaner anyway.<br><br>Keats<br><br>Shane Farmer wrote:<br>> Hi All,<br>><br>> I have been looking around for a while loop to no avail. As such I
<br>> have implimented a very basic while loop directive. I am using an<br>> older version of WM (1.0 or 1.1) and was wondering if it possible to<br>> create 2 subdirectives, break and continue, and if anyone would have
<br>> some pointers on how to go about doing this.<br>><br>> The code is _very_ basic ATM and simply loops while ever the<br>> conditional arg is true and evaluates [block.write(...)] on the block arg.<br>>
<br>> Im am all ears for better design startegies for this directive as well.<br>><br>> Thanks in advance<br>> Shane<br>> ------------------------------------------------------------------------<br>><br>
> -------------------------------------------------------------------------<br>> Using Tomcat but need to do more? Need to support web services, security?<br>> Get stuff done quickly with pre-integrated technology to make your job easier
<br>> Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo<br>> <a href="http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">
http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642
</a><br>> ------------------------------------------------------------------------<br>><br>> _______________________________________________<br>> Webmacro-user mailing list<br>> <a href="mailto:[email protected]" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">
[email protected]</a><br>> <a href="https://lists.sourceforge.net/lists/listinfo/webmacro-user" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">https://lists.sourceforge.net/lists/listinfo/webmacro-user
</a><br>><br><br><br><br>-------------------------------------------------------------------------
<br>Using Tomcat but need to do more? Need to support web services, security?<br>Get stuff done quickly with pre-integrated technology to make your job easier<br>Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo
<br><a href="http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642
</a><br>_______________________________________________
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https://lists.sourceforge.net/lists/listinfo/webmacro-user
</a><br></blockquote></div><br>
</span></div><br>-------------------------------------------------------------------------<br>Using Tomcat but need to do more? Need to support web services, security?<br>Get stuff done quickly with pre-integrated technology to make your job easier
<br>Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo<br><a onclick="return top.js.OpenExtLink(window,event,this)" href="http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642" target="_blank">
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