=head1 NAME
DbFramework::Attribute - Attribute class
=head1 SYNOPSIS
use DbFramework::Attribute;
my $a = new DbFramework::Attribute($name,$default_value,$is_optional,$data_type);
$name = $a->name($name);
$value = $a->default_value($value);
$opt = $a->is_optional($boolean);
$type = $a->references($data_type);
$bgc = $a->bgcolor($bgcolor);
$sql = $a->as_sql;
$s = $a->as_string;
$html = $a->as_html_form_field($value,$type);
$html = $a->as_html_heading($bgcolor);
=head1 DESCRIPTION
A B<DbFramework::Attribute> object represents an attribute (column) in
a table (entity).
=head1 SUPERCLASSES
B<DbFramework::Util>
=cut
use strict;
use vars qw( $NAME $DEFAULT_VALUE $IS_OPTIONAL $REFERENCES $BGCOLOR);
use Alias;
## CLASS DATA
my %fields = (
NAME => undef,
DEFAULT_VALUE => undef,
IS_OPTIONAL => undef,
# Attribute 0:N References 0:1 DefinitionObject (DataType)
REFERENCES => undef,
BGCOLOR => '#007777',
);
##-----------------------------------------------------------------------------
## CLASS METHODS
##-----------------------------------------------------------------------------
=head1 CLASS METHODS
=head2 new($name,$default_value,$is_optional,$data_type)
Create a new B<DbFramework::Attribute> object. I<$name> is the name
of the attribute. I<$default_value> is the default value for the
attribute. I<$is_optional> should be set to true if the attribute is
optional or false. I<$data_type> is a B<DbFramework::DataType>
object.
=cut
sub new {
my $proto = shift;
my $class = ref($proto) || $proto;
my $self = bless { _PERMITTED => \%fields, %fields, }, $class;
$self->name(shift);
$self->default_value(shift);
$self->is_optional(shift);
$self->references(shift);
return $self;
}
##-----------------------------------------------------------------------------
## OBJECT METHODS
##-----------------------------------------------------------------------------
=head2 name($name)
If I<$name> is supplied sets the attribute name. Returns the
attribute name.
=head2 default_value($value)
If I<$value> is supplied sets the default value for the attribute.
I<$value> should be compatible with the the data type set by
references(). Returns the default value for the attribute.
=head2 is_optional($boolean)
If I<$boolean> is supplied sets the optionality of the attribute
(i.e. whether it can contain NULLs.) I<$boolean> should evaluate to
true or false. Returns the optionality of the attribute.
=head2 references($data_type)
If I<$data_type> is supplied sets the data type of the attribute.
I<$data_type> is an ANSII data type object
i.e. B<DbFramework::DataType::ANSII> or a driver-specific object
e.g. B<DbFramework::DataType::Mysql>. Returns the data type object.
=head2 bgcolor($bgcolor)
If I<$color> is supplied sets the background colour for HTML table
headings returned by as_html_heading(). Returns the current
background colour.
=head2 as_sql($dbh)
Returns a string which can be used to create a column in an SQL
'CREATE TABLE' statement. I<$dbh> is a B<DBI> handle.
=cut
sub as_sql {
my($self,$dbh) = (attr shift,shift);
my $sql = "$NAME ";
$sql .= $REFERENCES->name;
$sql .= '(' . $REFERENCES->length . ')' if $REFERENCES->length;
$sql .= " NOT NULL" unless $IS_OPTIONAL;
$sql .= " DEFAULT " . $dbh->quote($DEFAULT_VALUE) if $DEFAULT_VALUE;
$sql .= ' ' . $REFERENCES->extra if $REFERENCES->extra;
return $sql;
}
##-----------------------------------------------------------------------------
=head2 as_html_form_field($value,$type)
Returns an HTML form field representation of the attribute. The HTML
field type produced depends on the name of object returned by
data_type(). This can be overidden by setting I<$type>. I<$value> is
the default value to be entered in the generated field.
=cut
sub as_html_form_field {
my $self = attr shift;
my $value = defined($_[0]) ? $_[0] : '';
my $type = defined($_[1]) ? uc($_[1]) : $REFERENCES->name;
my $length = $REFERENCES->length;
my $html;
SWITCH: {
$type =~ /(INT|DATE)/ &&
do {
$html = qq{<INPUT NAME="$NAME" VALUE="$value" SIZE=10 TYPE="text">};
last SWITCH;
};
$type =~ /CHAR$/ &&
do {
$html = qq{<INPUT NAME="$NAME" VALUE='$value' SIZE=30 TYPE="text" MAXLENGTH=$length>};
last SWITCH;
};
$type eq 'TEXT' &&
do {
$value =~ s/'//g; # remove quotes
$html = qq{<TEXTAREA COLS=60 NAME="$NAME" ROWS=4>$value</TEXTAREA>};
last SWITCH;
};
$type eq 'BOOLEAN' &&
do {
my $y = qq{Yes <INPUT TYPE="RADIO" NAME="$NAME" VALUE=1};
my $n = qq{No <INPUT TYPE="RADIO" NAME="$NAME" VALUE=0};
$html = $value ? qq{$y CHECKED>\n$n>\n} : qq{$y>\n$n CHECKED>\n};
last SWITCH;
};
# default
my $size = ($length < 30) ? $length : 30;
$html = qq{<INPUT MAXLENGTH=$size NAME='$NAME' VALUE='$value' SIZE=$size TYPE="text">};
}
return $html;
}
##-----------------------------------------------------------------------------
=head2 as_string()
Return attribute details as a text string.
=cut
sub as_string {
my $self = attr shift;
my $s = "$NAME(" . $REFERENCES->name;
$s .= ' ('. $REFERENCES->length . ')' if $REFERENCES->length;
$s .= " '$DEFAULT_VALUE'" if $DEFAULT_VALUE;
$s .= ' NOT NULL' unless $IS_OPTIONAL;
$s .= ' ' . $REFERENCES->extra if $REFERENCES->extra;
#print " $FUNCTION" if $FUNCTION;
return "$s)\n";
}
##----------------------------------------------------------------------------
sub _input_template {
my($self,$t_name) = (attr shift,shift);
return qq{<TD><DbField ${t_name}.$NAME></TD>};
}
##----------------------------------------------------------------------------
sub _output_template {
my($self,$t_name) = (attr shift,shift);
return qq{<TD BGCOLOR='$BGCOLOR'><DbValue ${t_name}.$NAME></TD>};
}
#-----------------------------------------------------------------------------
=head2 as_html_heading($bgcolor)
Returns a string for use as a column heading cell in an HTML table.
I<$bgcolor> is the background colour to use for the heading.
=cut
sub as_html_heading {
my $self = attr shift;
my $bgcolor = shift || $BGCOLOR;
my $text = $NAME;
$text .= ' ('.$REFERENCES->extra.')' if $REFERENCES->extra;
qq{<TD BGCOLOR='$bgcolor'>$text</TD>};
}
1;
=head1 SEE ALSO
L<DbFramework::DataType::ANSII> and L<DbFramework::DataType::Mysql>.
=head1 AUTHOR
Paul Sharpe E<lt>paul@miraclefish.comE<gt>
=head1 COPYRIGHT
Copyright (c) 1997,1998,1999 Paul Sharpe. England. All rights
reserved. This program is free software; you can redistribute it
and/or modify it under the same terms as Perl itself.
=cut