Django-Rest-Framework：在Django settings.py中全局设置分页类

Question

I'm trying to make a default pagination on all api calls:

http://www.django-rest-framework.org/api-guide/pagination/#modifying-the-pagination-style

And now I want to make my CustomPagination work globally:

class CustomPagination(PageNumberPagination):
    """
    自定义分页器
    """
    page_size = 10
    page_size_query_param = 'page_size'
    max_page_size = 1000

I want the register the class to the settings.py :

# =========== REST Framework ==============
REST_FRAMEWORK = {
    'DEFAULT_PAGINATION_CLASS': 'football.views.CustomPagination',
    'DEFAULT_FILTER_BACKENDS': ('rest_framework.filters.DjangoFilterBackend',),
}

Still, it raised an error:

ImportError: Could not import 'football.views.CustomPagination' for API setting 'DEFAULT_PAGINATION_CLASS'. AttributeError: module 'football.views' has no attribute 'CustomPagination'.

How can I work around it?

Answer 1

I encountered the same problem, and finally I fingered out it was because the module views.py was not correctly loaded because I didn't create the rest api folder by manage.py startapp and there is no item for it in INSTALLED_APPS of project's setting.py file.
I moved the CustomPagination paging class to views.py of my first app which was created by manage.py startapp then it worked.

To debug, you can add following line to rest_framework/settings.py source code like this:

module = import_module(module_path)  # Original code
if (setting_name == "DEFAULT_PAGINATION_CLASS"):  # Added code
    print(dir(module))  # Added code
return getattr(module, class_name)   # Original code

If AttributeError raised, it should be like: (only builtin attributes in the list)

# ./manage.py runserver 0:8000
Performing system checks...

['__builtins__', '__cached__', '__doc__', '__file__', '__loader__', '__name__', '__package__', '__spec__']
Unhandled exception in thread started by .wrapper at 0x7fd60a265510>
Traceback (most recent call last):

If it works, CustomPagination should be listed in the list:

# ./manage.py runserver 0:8000
Performing system checks...

['some-other-classes', 'PageNumberPagination', 'CustomPagination', '__builtins__', '__cached__', '__doc__', '__file__', '__loader__', '__name__', '__package__', '__spec__', 'models', 'random', 'reverse', 'settings']
System check identified no issues (0 silenced).