Carbon 14

This library QraphQL like query language that exposes the data in a Falcor like format.

Take a look to the tests in the file tests/test_queries.py

Django integration

To integrate with Django you will require Django REST Framework.

Put this in your urls.py file, passing in the nodes parameters the nodes you will handle in this endpoint.

...

from carbon14.django import GraphQLView

urlpatters = [
    ...
    url(r'graphql/$', GraphQLView.as_view(nodes=[Users, Groups])),
    ...
]

...

To expose a resource write the spec for a Node:

from carbon14.neonode import ModelNode
from .models import Author, Book

class Books(ModelNode):
    class Meta(ModelNode.Meta):
        name = 'books'
        source = Books.objects.all()
        fields = ('id', 'title', 'author')
        nested_fields = {'author': 'authors'}


class Authors(ModelNode):
    """Describe how to retrieve and expose authors

    Id you want to do permission checking during filtering or computing  any
    custom field remember that `self.ctx` in Django refers to the request object
    so. Using `self.ctx.user` you can know the user that is querying.

    """

    class Meta(ModelNode.Meta):
        # name for this node type
        name = 'authors'  
        
        # the data source when queried in the root level
        source = Author.objects.all()  
        
        # exposed fields
        fields = (
            'id', 
            'first_name', 
            'last_name', 
            'full_name', 
            'is_alive', 
            'description',
        )
        
        # exposed fields that refer to another Node type
        nested_fields = {'books': 'books', 'kill': 'authors'}
        
        # is this node accessible by Anonymous user? (default: False)
        is_public = True

        # is this node exposed in the RootNode? (default: True)
        exposed = True

        # by default ModelNode will do some query optimization when querying
        # related data. But if you wans to specify that when querying
        # `description` the query should pre-fetch the books do this:
        optimize = {'description': 'books'}


    def resolve_full_name(self, author, lower=False, **kwargs):
        """
        Custom field of this node, needs to be listed in `fields` or
        `nested_fields` to be exposed. It can receive parameters.

        Query examples:

        Being author: {id: 1, first_name: 'Alex', last_name: `von Baum`}
        Query: `authors { full_name }`
        Output: `{'authors': {'1': {'full_name': 'Alex von Baum'}}}``

        Query: `authors { full_name (lower: true) }`
        Output: `{'authors': {'1': {'full_name': 'alex von baum'}}}``

        If you want to return a object from another node list this field
        in `nested_fields` and point to the kind of node it returns.

        Note that this kind of field can be used for mutations, because
        it gets called every time is exposed. Check `resolve_kill`
        """
        full_name = f'{author.first_name} {author.last_name}'
        if lower:
            full_name = full_name.lower()
        return full_name

    def resolve_description(self, author, **kwargs):
        return f'Author of: {author.books.all()}'

    def resolve_kill(self, author, **kwargs)
        """Mutation over author

        This kind of mutation can be called as:

        Query: `authors { kill }`

        **It can be also implemented in the Author model class.
        """
        author.is_alive = False
        author.save()
        return author

    def filter(self, _source, name_startswith='', **kwargs):
        """Filtering function.

        The argument  `kwargs` are the arguments passed to this node like here `name_startswith`: 

        Query: `authors (name_startswith='Abc') { title }`
        
        You can manage visibility and permissions here end in the fields because
        `self.ctx` is the request made, so `self.ctx.user` is the user querying
    
        """
        if name_startswith:
            _source = _source.filter(first_name__startswith=name_startswith) 
        return _source

Testing

Install the package in development mode:

$ python setup.py develop

Install py.test and run:

$ py.test