Hans Dieter Pearcey > CouchDB-View > CouchDB::View::Document

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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.

SEE ALSO ^

CouchDB::View::Server CouchDB::View

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