I’m not sure if any existing template libraries are garbage free, though I
like the idea in general at least.
On Wed, Dec 25, 2019 at 14:42 Volkan Yazıcı <volkan.yaz...@gmail.com> wrote:
> On Wed, Dec 25, 2019 at 7:38 AM Ralph Goers <ralph.go...@dslextreme.com>
> wrote:
> > FWIW, I am not necessarily proposing we implement that. I am
> > trying to point out that your templating approach doesn’t really
> > seem to be tied to JSON, [...] I could just as easily imagine an
> > XML template with xml resolvers.
>
> This is a striking observation Ralph! (I think Carter Kozak is
> pointing in the same direction in the thread.) Consider the following:
> if we provide a fully-fledged template engine (e.g., Velocity,
> FreeMarker, Thymeleaf, Pippo) with sufficient expressiveness (here
> consider someone trying to emit epoch seconds in floating point format
> from LogEvent#getInstant()) and escaping utilities (e.g.,
> {Json,Sgml,Yaml}Helpers.escapeString()), users can render whatever
> text-based output they want, be it XML, JSON, YAML, HTML, etc. If we
> would look deep enough, all what LogstashLayout, PatternLayout, etc.
> are trying to achieve is a short-sighted attempt to fill in this
> template engine gap.
>
> Here is a thought experiment: Given a VelocityLayout with all its
> whistles and bells (e.g., EscapeTool[1]), are there any text-based
> layouts we know of that is not expressible by VelocityLayout? Further,
> I expect VelocityLayout to outperform the existing individual
> text-based layouts due to its template compilation. (You can repeat
> the same experiment by replacing "Velocity" with your favorite Java
> templating engine.)
>
> I am strongly in favor of moving towards this direction rather than
> introducing ad-hoc layouts for each text-based format that Log4j needs
> to emit.
>
> [Thanks for the rest of the comments Ralph. I skipped replying to them
> on purpose to just focus on this significant observation.]
>
> [1]
> http://velocity.apache.org/tools/devel/apidocs/org/apache/velocity/tools/generic/EscapeTool.html
>
--
Matt Sicker <boa...@gmail.com>
