Re: inflating columns to objects

[prev] [thread] [next] [Date index for 2004/10/27]

I wrote:
> I'm having a problem on a Maypole edit page, but I think the problem is 
> something I'm doing wrong in Class::DBI with respect to Class::DBI::AsForm.
> 
> I'm trying to use an object to represent a column:
> 
>    seq   LONGTEXT NOT NULL,
>    INDEX (seq(10))
> 
> The value in the database is a potentially long string (and that is what 
> I want to keep in the database :) but when it is displayed, I want to 
> format it into lines of a reasonable length. I have written a class (see 
> below) and added this line in my driver class (which isa Class::DBI):
> 
>    QD1::Sequence->has_a(seq => 'my_seq', deflate => 'deflate');
> 
> This works when displaying a list, but when I click on edit I get an
> empty space where the textbox should be:

My debugging has thrown up a possibility :)

Class::DBI::AsForm::to_field is what is called on the template to 
display the column. Within that routine it calls _to_textarea, which 
looks like this:

sub _to_textarea {
     my ($self, $col) = @_;
     my $a = HTML::Element->new("textarea", name => $col);
     if (ref $self) { $a->push_content($self->$col) }
     $OLD_STYLE && return $a->as_HTML;
     $a;
}

What's happening is that when it says { $a->push_content($self->$col) } 
my inflated object is getting pushed into @a->_content. This seems to be 
A Bad Thing and results in nothing being output by the element when the 
HTML::Element::as_xml method is called on it. If I change that line to read:

     if (ref $self) { $a->push_content('' . $self->$col) }

then the formatted content of my column gets displayed in a textarea 
element as it should. But I have no idea whether my change fixes a bug 
in AsForm or breaks some other cases, or whether there's a better fix.

Does this inspire anybody to see a good solution to my problem?

Thanks, Dave