Inheritance and Custom constructors

Hi all,

the documentation is a bit vague about how to do define your own constructor when inheritance is being performed. The documentation is here: https://neomodel.readthedocs.io/en/latest/extending.html

The example given is:

class Item(StructuredNode):
    name = StringProperty(unique_index=True)
    uid = StringProperty(unique_index=True)

    def __init__(self, product, *args, **kwargs):
        self.product = product
        kwargs["uid"] = 'g.' + str(self.product.pk)
        kwargs["name"] = self.product.product_name

        super(Item, self).__init__(self, *args, **kwargs)

that just doesnt work - you can run this yourself and realise that you will get an exception on StructuredNode constructor.

One can make it work with the following:

class Item(StructuredNode):
    name = StringProperty(unique_index=True)
    uid = StringProperty(unique_index=True)

    def __init__(self, product, *args, **kwargs):
        self.product = product
        kwargs["uid"] = 'g.' + str(self.product.pk)
        kwargs["name"] = self.product.product_name

        super(Item, self).__init__(*args, **kwargs)

Still, there’s a problem when the .save() method is being called on that object. This happens because it tries to inflate an object using this constructor, without “product” argument being provided.

a solution would be:

class Item(StructuredNode):
    name = StringProperty(unique_index=True)
    uid = StringProperty(unique_index=True)

    def __init__(self, product = None, *args, **kwargs):
        if product is not None:
            self.product = product
            kwargs["uid"] = 'g.' + str(self.product.pk)
            kwargs["name"] = self.product.product_name

        super(Item, self).__init__(*args, **kwargs)

Which is quite ugly and I believe that probably not the intended implementation. How is the correct way to perform it? I can improve the docs on that if required.

[aanastasiou]

@MarcoLotz I think that I may have misinterpreted your question. If you are not looking for advice on a specific problem you are dealing with and you are simply highlighting an issue with the documentation then you are welcome to provide a PR about it.

[aanastasiou]

@MarcoLotz What do you think?