Re: [Maypole] mixing of tables in create

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--- Josef Chladek <j.chladek@xxxxxxxxxxxxxxxx.xx> wrote:

> 
> Am 01.02.2005 um 18:09 schrieb Peter Speltz:
> 
> > I was thinking override create_from_cgi. you should just be able to 
> > put a sub
> > in your base model class (or just class you want the override) called
> > create_from_cgi.
> 
> ok, so i did, this opens a can of worms for me:
> 
> sub create_from_cgi {
>      my $class = shift;
>      my $article = $class->SUPER::create_from_cgi(@_);
>      my $textblock = Article::Textblock->create_from_cgi(@_);
>      $textblock->article($article->id);
>      $textblock->update;
>      $article;
> }
> 
> with this i was able to insert the title, lead along with one block in 
> the two tables.
> 
> 1) i hardcoded the formfield in the addnew template, how could this be 
> done automatically? Article::Article->columns(All => qw/title lead 
> block/) is not the way, it of course tries to retrieve the value of 
> block in the article table
> 2) related to this, what has to be done in the edit template
> 3) what about multiple blocks? how should the formfields be named 
> (block -> i get an array), block1, block2 ... -> this breaks the 
> automatic insertion)
> 
> 

 Alright!. I'm working on this today too. We can work together. Do you use
AsForm?  

Here's where i'm at on mixing of tables in create. I've spent a lot of time on
this and code is mostly done. just details to work out.  

1) AsForm should make foreign inputs (as i call them) automatically when it
knows too.

   ? How does asForm know to make inputs ?  

Ideally it should know from 1 to 1 relationship declarations. Otherwise you
might as well call it yourself with the foreign class.  Two one to one
relationships in cdbi: might_have  (but this is a 0-1:1 so we don't know if we
really want inputs or not) and has_a (but this is really a 0-M:1 so we have a
problem). 

   Solutions: 
   1.   "has_one"  -- a new relationship that is just like might_have but no  
might. maybe "must_have" would be a better name? 
    i posted has_one for testing in this thread
http://groups.kasei.com/mail/arc/cdbi-talk/2005-01/msg00136.htmlrevisited

   2. for has_a relationships a hint could be passed in args to indicate this
is a one to one rather than an 0-M:1. Then asform could make inputs rather than
a select box. 


   ? How should it name those inputs ? Where should it put them in the hash
it's returning?

So a call "create_from_cgi($r->params)" or "create($r->params)" will be able to
create all components of an object.  It could put them in a hash keyed on
accessor name. That's what my AsForm does now. Then the templates expand the
hashes with a FOREACH to display the inputs.  We need a naming convention that
create_from_cgi and create will recognize. I've thought about
"accessorName__AsForeign__columnName" . Then in the create* call the input name
could be split on "__AsForeign__" and you'd get accessor and column. the class
can then be derived from meta_info for teh accessor (see output of
$class->meta_info as its undocumented) and another create_from_cgi or create 
call could be made with that class. 

However, if one wants an arbitrary number  of same object like Josef, say for a
has_many relationship, it gets  weird. I don't know what to do here. With my
has_one and might_have relationships i can do this :

    has_one(main_block=> 'Block' ...); 
# input names for cols for this element could be : main_block__AsForeign__*
    has_one(block0    => 'Block' ...);
    might_have(block1 => 'Block' ...);
    might_have(block2 => 'Block' ...);


Currently a call to my AsForm::to_cgi method with this setup up would return:
{
  main_block => { col1 => htmlelement ...},
  block0     => { col1 => ...},
  ...
}

but it could easily format names and put all in top level hash:

{ main_block__AsForeign__col1 => htmlelement,
  main_block__AsForeign__col2 => ...,
  block0__AsFor...
}

  Except with them in hashes by accessor Templates can tweak input names
easier. Don't know. I kind of like the later better as i use FromCGI. 


Thoughts?


=====
pjs


		
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