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 <http://wiki.apache.org/couchdb/HttpViewApi>. 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 <http://wiki.apache.org/couchdb/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 <http://wiki.apache.org/couchdb/HttpViewApi> 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.