On Sun, Aug 25, 2013 at 5:45 PM, Henrik Lindberg
<[email protected]> wrote:
>> This may be silly, but "Extended Puppet Templates" seems more logically
>> abbreviated "EPT" - why "EPP"?
>>
> Does it say "Extended Puppet Templates" somewhere? The idea is to do the
> same as in Ruby, i.e. "Embedded Ruby" = ERP, "Embedded Puppet" = EPP.
I should have said "Embedded", not "Extended". And, fair enough -
Embedded RuBy templates are not "ERT", they are "ERB". So Embedded
PuPpet templates can be "EPP".
>> Could you include a link to the Puppet DSL in the text? It's easy to
>> think that that means Puppet itself (e.g., resource declarations), when
>> really it is a form of Ruby (I think). The link will add context.
>>
> Sorry, but I don't get your question. EPP is to Puppet what ERB is to ruby.
> The EPP content is in a file, typically with extension .epp, but can be
> anything except .pp (which is naturally "not embedded puppet code").
>
> But, I think you are asking something else...
I'm asking, what language do I use between <% %>? Can I write
<%
file {
'/etc/motd':
content => "hello, world\n"
}
%>
which is what "Embedded Puppet" suggests to me. That's not the case,
and "Puppet DSL" is only slightly less unclear, unless the reader is
enough of a Rubyist to realize that "DSL" in the Ruby community refers
to a modified Ruby environment, and not an entirely different
language. Basically, please add a link so I know unambiguously what I
can and cannot do between <% .. %>.
>> As for validation of filetypes, I think this is a good idea, but I don't
>> like the <%- ($x, $y) :html -%> syntax for this. I'd prefer something a
>> little more explicit and expandable, perhaps
>> <%- ($x, $y) syntax => html -%>
>>
> The idea was to mimic the same specification in ARM-4 Heredoc, where the
> syntax is ':syntax'.
I could make the same criticism there (I just haven't gotten to that ARM yet).
> I am not super happy with the somewhat magic <%- () -%> construct. It
> allowed me to reuse parameter parsing. Did not spend too much time on
> figuring out alternatives, but the ones that came to mind I thought were
> worse.
In the absence of other data, explicit is better than implicit:
<%- params => ($x, $y),
syntax => :html -%>
> Whether it should be restricted scope of not by default I don't know. It
> could be a chore to have to write a hash with name to value associations.
EPP doesn't need to inherit the warts of ERB, at least not by default.
If backward-compatibility is easy but not the defalut, then new users
will not accidentally use the deprecated feature - at least not
without careful thought.
In Python, if you wanted to pass your local variables to a called
function, you could use something like
called_function(**locals())
Which is explicit (and very rare). I don't necessarily think that EPP
should use the ** syntax, but certainly using an explicit option for
the behavior is possible.
> There is a Redmine issue where it is discussed if it is good or bad that the
> template functions can join results from multiple templates. I would prefer
> if it was just one, and instead call a join function if that behavior is
> needed.
I think the sticking point on that bug is that the change would be
backward-incompatible. The same is not the case for EPP. If the EPP
functions *never* concatenate by default, then users converting from
ERB templates will need to manually apply the concatenation during
conversion.
Dustin
--
You received this message because you are subscribed to the Google Groups
"Puppet Developers" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/puppet-dev.
For more options, visit https://groups.google.com/groups/opt_out.
