Hi Dennis,
> With respect to netcdf (at least the C version), it is the
> case that these characters can appear
> unescaped: _. at +-
>
> It should be noted however that dot in particular causes
> problems for accessing remote datasets through DAP because
> the dot character is used in DAP constraints to specify
> fields inside DAP Sequences or Structures or Grids.
Out of interest, what happens if you do make an (open)dap request which
involves an attribute name that contains 1 or more special characters
(not just '.')? Does it fail? Is it just '.' which is the villain, or
any netcdf special character?
I guess I was (naively!) assuming that occurrences of variable/attribute
names in, say, URLS would be escaped using the normal encoding rules,
e.g.
test.opendap.org/dap/data/nc/sst.mnmean.nc.gz?blah&blah&attname="cf.foob
ar"&value="baz"
Several of the examples at
http://docs.opendap.org/index.php/QuickStart
appear to employ a similar mechanism.
> This means that whatever choice you make, you need to
> enshrine it in a standard somewhere so that at least there is
> a chance that people will avoid it.
Yes, naturally that would be the intention - *if* a consensus could be
reached.
> Personally, I would think that a two character sequence is
> least likely to be used by others, but two underscores is
> probably not a good choice.
I wasn't proposing that :-)
> I would think something like _at_@
> ++ might be a better choice.
Either of those would be a tough sell, IMHO! Though it's always good to
get alternative suggestions/perspectives.
Regards,
Phil
Received on Tue Jan 29 2013 - 05:44:21 GMT
