[Bf-committers] Python Access to some properties of nodes

[Bartek Skorupa (priv)]

Thank you Lukas.
In a nutshell it means that it's better not to add those properties to sockets right?
Without going deeper into it I'd say that it's not a big deal working the old way or use your suggestions.
I only said that it would be easier if we had such properties, but it seems that adding them could make other areas harder to maintain.
If so, I can live with that.

Thank you again.

Cheers
Bartek Skorupa

www.bartekskorupa.com

On 20 gru 2012, at 11:30, Lukas Tönne <lukas.toenne at gmail.com> wrote:

> Slightly nicer: define 'links' as a property instead of a method:
> 
> class NodeSocket(StructRNA, metaclass=RNAMeta):
>    __slots__ = ()
> 
>    @property
>    def links(self):
>        """List of node links from or to this socket"""
>        return [link for link in self.id_data.links if
> link.from_socket == self or link.to_socket == self]
> 
> On Thu, Dec 20, 2012 at 11:10 AM, Lukas Tönne <lukas.toenne at gmail.com> wrote:
>> In the bNodeSocket DNA we currently have a sock->link pointer which
>> directly points to a bNodeLink. However, this only works for input
>> links with the current connectivity model (input only has one possible
>> link, outputs can have many). Future nodes can use a different
>> connectivity model, then this pointer would be pretty useless. Also
>> this pointer is not totally reliable in all cases, e.g. can be invalid
>> during node updates. For this reason i would discourage using this
>> pointer and always use the nodetree->links list to find connections
>> from/to a specific socket. Eventually i'd like to remove the
>> sock->link pointer as well to make maintenance easier and remove a
>> potential error source.
>> 
>> For getting connections of a socket i would instead suggest to add a
>> number of python methods to the NodeSocket class (can be done in
>> bpy_types.py). With python this can be done very nicely:
>> 
>> class NodeSocket(StructRNA, metaclass=RNAMeta):
>>    __slots__ = ()
>> 
>>    # returns a list of links to or from this socket
>>    def get_links(self):
>>        return [link for link in self.id_data.links if
>> link.from_socket == self or link.to_socket == self]
>> 
>> If necessary such functions could also be added to the RNA directly.
>> 
>> 
>> On Thu, Dec 20, 2012 at 3:30 AM, Dan Eicher <dan at trollwerks.org> wrote:
>>> Assuming Campbell's OK with it it wouldn't be too terribly hard to add
>>> something like Socket.link to push the iterating over the links into C
>>> since IIRC that's how it works internally.
>>> 
>>> I personally won't have time to mess with it until after New Years but if
>>> someone else wants to bang their head against makesrna and node tree
>>> structs it might turn out to be as simple as wrapping an existing function
>>> (though I do seem to recall that the node links were a little tricky to
>>> wrap originally).
>>> 
>>> Dan
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