Re: [netcf-devel] [PATCH 7/7] Let the lens handle single quotes instead of the XSLT and XSLT extensions
On Wed, Jul 29, 2009 at 06:51:26PM +0200 David Lutterkort wrote:
On Thu, 2009-07-23 at 14:37 +0200, Jonas Eriksson wrote:
> This is the second in a two-stage commit where we move from
> the standard shellvars-lens to one that strips the single
> quotes before and after strings.
>
> data/lenses/ifcfg.aug: Strip single (and double) quotes and
> re-insert them after save.
This doesn't work properly - when you modify a lens, you should also run
it through 'augparse data/lenses/ifcfg.aug' to typecheck it, and the
modified lens produces a typechecking error (typechecking isn't done by
default since it can be _very_ slow)
The typecheck error from augparse is
data/lenses/ifcfg.aug:22.2-27.19:Failed to compile array
data/lenses/ifcfg.aug:23.22-.42:exception: overlapping lenses in tree union.put
Example matched by both: ''
First lens: data/lenses/ifcfg.aug:16.15-.59
Second lens: data/lenses/ifcfg.aug:23.31-.42
The issue is that Augeas can't decide how to write out variable values
when it goes from tree -> file. For a variable VAR with value VAL in the
tree, Augeas can legally write this as VAR=VAL, VAR='VAL', or
VAR="VAL"
- and it has no way of knowing which one is correct. For example, if VAL
contains spaces, no quotes would be incorrect.
Ok, this is not good. I can see that this is now touched in the
schema tutorial which I should have checked with before
submitting this patch (which was written a while back).
Are there any thoughts on letting augeas have some sort of
writeback-awareness that would let it react to this? Some sort of
value-filter perhaps (foo bar => 'foo bar', fo'o =>
"fo'o").
That's the reason why the shellvars lens doesn't strip
quotes
automatically :) (Plus, in general, it matters when you look at an entry
in the tree whether it's enclosed in single or double quotes, and
there's no way to decide automatically which one is correct)
For general shellvars I can understand this, but now we have a
very much simplified case which would let us cut corners to
gravely simplify the C-code.
> data/xml/util-get.xsl: Remove insertion of single quotes in
XSLT
If this is just for simplification, I would just drop this patch and 6/7
- otherwise, what problem did you run into ?
As said in 6/7, this needs to be handled for all variables, not
just the ones that can contain spaces. What I forgot to mention
in that mail is that I believe YaST (the default config tool for
SuSE) defaults to do the single-quoting on all ifcfg-values.
/Jonas
--
Jonas Eriksson
Consultant at AS/EAB/FLJ/IL
Phone: +46 8 58086281
Combitech AB
Älvsjö, Sweden