[development] Body and teaser as fields

[Barry Jaspan]

Now that Field API is in core it is time to start using it.  I have 
an initial suggestion: change node body and teaser from special cases 
to normal fields.  I suspect this is going to be quite controversial 
so I thought I'd get some feedback here before evening bothering to 
start looking at the code.

This message is not about the details of the implementation; I'm sure 
there will be subtleties and complexities to work.  I'm just asking 
about the concept.

Concept:

Remove all special processing for $node->body and 
$node->teaser.  Create two fields, body and teaser, both text 
fields.  Assign both fields to every existing content type with a 
"body field" using the textarea widget.  For existing nodes, as part 
of the upgrade path, initialize the teaser field value with whatever 
teaser would normally be generated automatically from the body.

Random thoughts:

- We will get to remove a bunch of code, much of it quite ugly, from 
node.module.

- Sites that really want an auto-generated teaser can remove the 
teaser field from a content type and use the text field's teaser 
Display Formatter in the teaser context.

- This will mean removing the body field from the node and 
node_revision tables, and creating a field_data_body table for it 
instead.  Don't worry about database query efficiency; that is a 
solved problem (see http://drupal.org/node/368674).

- With $node->body and $node->teaser being normal fields, they will 
not be available for overloaded use as the complete rendered output 
of the node.  Hurray!  We can use $node->content = 
drupal_render($node) or something like that.

- We might want to think about adding other fields to our default 
content types.  Perhaps Article should have a Subtitle field, 
etc.  This is a whole topic in itself.

Comments?

Thanks,

Barry