Incorrect edge schema generation in 0.7.0

[volodymyrko]

Hi
there seems be an issue with generating schema (CollectionBase.schema) for Edges/Relations with custom attributes (like SpecializesIn ) in specific case.
Here are few examples:

1. when schema method is run for SpecializesIn first (before any other relations) everything is fine

(Pdb) self._graph.edges['specializes_in'].schema().fields.keys()
<class 'tests.data.SpecializesIn'>
dict_keys(['expertise_level', '_key'])   # 'expertise_level' is present

(Pdb) self._graph.edges['studies'].schema().fields.keys()
<class 'arango_orm.collections.Relation'>
dict_keys([])

2. if schema method is run for Relation first it does not generate correct schema

(Pdb) self._graph.edges['studies'].schema().fields.keys()
<class 'arango_orm.collections.Relation'>
dict_keys([])

(Pdb) self._graph.edges['specializes_in'].schema().fields.keys()
<class 'tests.data.SpecializesIn'>
dict_keys([])  # IS EMPTY

is happens because Relation._cls_schema is already generated/cached at the first step (self._graph.edges['studies'].schema()) and it is used when self._graph.edges['specializes_in'].schema() is run. SpecializesIn is inherited from Relation so it uses Relation._cls_schema data

[SoundsSerious]

Hi @volodymyrko

I agree there are some issues with the schema caching. This was something I implemented as I found repeated calls to the schema generated actually created a pretty significant memory leak.

I dont know what the right answer is, a couple ideas have been floated:

1. get rid of marshmallow which has been causing some problems like the memory leak
2. provide an explicit method to cache schema Apispec integration #119
3. improve the caching subclassing schema #115

[overbost]

@volodymyrko can you check the last commit #122 (it's merged into master now).
This should fix your issue.

[volodymyrko]

@overbost , my tests passed successfully.
thanks

[PTank]

Hi, can you update the pypi package to the last version to fix this issue ?
Thanks

[kashifpk]

@PTank Done. @PTank @volodymyrko @overbost @SoundsSerious Please use https://github.com/kashifpk/arango-orm for the future as I no longer have push access to this repo. I'll be pushing updates to this new repo in the future.