> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On
>
> Jose Alberto Fernandez wrote:
> >
> > > From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]]On
> > >
> > >
> > > Jose Alberto Fernandez wrote:
> > > >
> > > > The point here is not how to escape but that the regular
> > > way to do this,
> > > > i.e., pass your value thru a function, or write a macro
> > > that calls that
> > > > function; they just polute the template and makes the whole
> > > thing dificult
> > > > to read.
> > > >
> > > > The need is for a mechanism that can perform this
> > > transformations implicitly
> > > > without having to call something everytime we type "${....}".
> > > >
> > >
> > > What's the downside again for postprocessing the rendered
> stream? I
> > > don't remember...
> > >
> >
> > Not sure what you mean, but don't you usually need to know
> the syntactic
> > context to decide what kind of processing to do?
>
> I'm not sure. Seems like if thats the case, then just using something
> like
>
> $foo.escape( $blargh )
>
> in the template would solve the problem. Or a VM
>
> #escape($blargh)
>
> and define the VM as appropriate. Or...
>
The above are the regular solutions. No one is denying that it can be done
that way. The problem with this solution is that when you need to escape 95%
of the template expansions then using the above does not sound that
appealling.
> Seems that Velocity has all the capability you need as is :
>
> 1) use a context tool in the template
> 2) use a Velocimacro in the template
> 3) Postprocess the rendered stream
> 4) Make your own writer to hand to velocity that will do the firing as
> vel writes into it.
>
> > The point is that within the template code you know, in
> principle, the
> > syntactic context in which you are expanding. Therefore you
> could direct
> > your custom listener to do different things at different points.
>
> Hm. So the listener would be fired at every insertion. How
> do you know
> syntactically where you are in the template if you have no information
> other than the glob that Vel wants to insert into the stream?
>
You can control that from the context. No one says that the "custom"
listener needs to be dum. The hooking mechanism for Velocity must be simple
but not how the listener works.
> If you don't know, then processing the output stream at once with a
> filter or tool is equivalent, right?
>
> Isn't doing it from strategic points in the template much better via a
> context tool, or wrapping in a VM?
>
It is a question of percentages, I guess. If 95% of your insersions require
escaping. Is it reasonable to provide a mechanism to reverse tell your
listener to stop escaping and use that in the 5% of the cases when you do
not require escaping.
How can one achive that?
Well you can provide access to your custom listener from the context. And
control it. You can define macros and so on. But the point of all these is
that you will need to use them much less than the other way around.
The whole point of this is giving you choices on how to acomplish what you
want.
> >
> > That, and the fact that constant text in the template does
> not get affected
> > by the listener operation, I think are good reasons against
> postprocessing.
> >
>
> That's true, if your template is setup with the constant stuff
> pre-escaped.
>
> But if the template is intended for XML-only output, meaning you have
> stuff pre-escaped, then whats wrong with wrapping the dyanmic inserts
> via context tool?
>
> I am not against a listener interface, per se. I have been thinking
> hard about this for similar purposes, but didn't want to do anything
> before 1.0. I guess what I don't understand, is why in-template
> solutions aren't appropriate.
>
As I said, it is a question of percentages. What do you want the default to
be given the problem space you are confronting.
And I am sure this is not only an XML issue. I am sure there will be other
problem domains that can be approached the same way.
> geir
>
> --
> Geir Magnusson Jr. [EMAIL PROTECTED]
> Developing for the web? See http://jakarta.apache.org/velocity/
>
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