ActiveRecord: Assigning and saving unsaved dependencies

[oddz]

Given two models Blog and Category would it be right to assign a blog to a category that hasn't been created yet? Then when the save() method is called on the Blog the Category would be saved through the Blog by being inserted first. Then the Blogs foreign key would be set to the Categories primary key.

$blog = new Blog();
$blog['title'] = 'The Blogs Title';
$blog['entry'] = 'entry for this blog...';
$blog['created'] = time();
$blog['category'] =  new Category(array('name'=>'vehicles'));
$blog->save(); // category inserted then blog 

The reason why I ask is because hypothetically in terms of a dependency the Category seems like it should exist before being assigned as a dependency to the Blog/Model which it would relate (shown below).

$category = new Category();
$category['name'] = 'vehicles';
$category->save(); // inserted and assigned primary key

$blog = new Blog();
$blog['title'] = 'The Blogs Title';
$blog['entry'] = 'entry for this blog...';
$blog['created'] = time();
$blog['category'] =  $category;
$blog->save(); 

One particular instance where this would be increasingly convenient is any one to one relationship.

$profile = Profile(array('email'=>'blah@blah.com'));
$profile->user = new User(array('name'=>'oddz'));
$profile->save(); // user would be saved before profile 

[Mastodont]

Why do you want to limit yourself only to 1-1 relationship?

$blog['category'] =  new Category(array('vehicles', 'bicycles')); 

the Category seems like it should exist before being assigned as a dependency to the Blog/Model which it would relate
You can create non-existent categories in constructor of Category class.

[oddz]

Why do you want to limit yourself only to 1-1 relationship?

Not limited to 1:1. The scenario presented merely represents a generic case.

You can create non-existent categories in constructor of Category class.

The system is generic. The class files are only responsible for defining model and table information. Running queries, collecting queries, saving and deleting data. Nothing more. Everything else is controlled outside of the core library files. That includes the management of specific entities (Category, Blog, ect). Assigning a Category to a Blog is specific to the application not the generic purpose of the library.

[Vali]

make sure you can rollback, so if your "user" fails to save, you don't save the "profile" (or anything else that might be linked to it)

[oddz]

If the user save were to fail the profile would not be saved.

I decided that advantages of this made it worth allowing. However, the same thing could also be accomplished the other way around.

$user = new User();
$user->name = 'oddz';
$user->profile = new Profile(array('email'=>'blah@blah.com'));
$user->save(); 

Just nice to be able to accomplish it both ways I think.

[Vali]

$user = new User();
$user->name = 'oddz';
$user->profile1 = new Profile(array('email'=>'blah1@blah.com'));
$user->profile2 = new Profile(array('email'=>'blah2@blah.com')); # failed
$user->profile3 = new Profile(array('email'=>'blah3@blah.com'));
$user->save(); 

If profile2 fails, but save profile1 and profile3, you will have a problem.

[oddz]

Well in that case all the profiles would be inserted in the same query. If that query fails the only data that would be inserted is the user currently. In the case which you provided only 2 queries will be executed not 4.