NAME
CouchDB::View::Document - CouchDB design document abstraction
SYNOPSIS
my $doc = CouchDB::View::Document->new({
_id => "_design/mystuff",
views => {
by_name => sub {
my ($doc) = @_;
dmap($doc->name, $doc);
},
by_whatsit => sub {
my ($doc) = @_;
require Whatsit::Parser;
dmap(Whatsit::Parser->parse($doc), $doc);
},
},
});
# use with a hypothetical client
$couchdb_client->put(
'/mydatabase/' . $doc->uri_id,
$doc->as_json,
);
DESCRIPTION
CouchDB::View::Document provides a Perlish interface to creating CouchDB views. It uses Data::Dump::Streamer to serialize coderefs, which are deserialized and used by CouchDB::View::Server.
WRITING VIEWS
Read the CouchDB wiki page on views if you have not already. Only Perl specifics will be mentioned here.
The map
function is already used in Perl. Instead, use dmap()
(as in the "SYNOPSIS") to map keys to values.
Perl does not have null
. Use undef
.
All the limitations of Data::Dump::Streamer apply to your view functions. In particular, if they use external modules, they will need to require
or use
them explicitly (see the Whatsit::Parser example in the "SYNOPSIS"). Likewise, closed-over variables will be dumped, but external named subroutines will not, so this won't work:
sub elide {
my $str = shift;
$str =~ s/^(.{10}).+/$1.../;
return $str;
}
my $doc = CouchDB::View::Document->new({
...
views => {
elided => sub {
dmap(elide($doc->{title}), $doc);
}
},
});
The definition of elide
is not transferred to the view server.
METHODS
new
my $doc = CouchDB::View::Document->new(\%arg);
Create a new design document. See the CouchDB view API for the details of \%arg
, though language
is ignored (always 'text/perl').
as_json
print $doc->as_json;
Use as_hash
(below) and JSON::XS to encode the result. This is suitable for passing directly to a PUT to CouchDB.
uri_id
print $doc->uri_id;
# '_design%2Fmyview'
Convenience method for the document name, since '/' must be escaped.
as_hash
print Dumper($doc->as_hash);
Return a hashref suitable for serializing to JSON, including serialized coderefs.
code_to_string
This method is called with a coderef and is expected to return a serialized representation of it. You probably don't need to use this unless you're subclassing CouchDB::View::Document.