Registering Functions from Blueprints

Forgive me if I'm not understanding something, I'm not too familiar with Flask–

I'm working on a large Flask API that I'd like to document using `flask-apispec`. To organize the different sections of the API, we use Flask's Blueprint mechanism and pull all of these into a single `app` in a main file.

It seems that in your documentation you need to call `docs.register(view_function)` on every `view_function` defined in your app; which in our case would require a disastrous amount of imports and would be really painful to maintain. I came up with the following bit of code:

```python
for (fpath, view_function) in app.view_functions.items():
blueprint_name = fpath.split('.')[0]
# only bound methods have a __self__ attribute, so we can check whether
# a view_function is a defined route or something included from a package
# or from Flask by using hasattr.
if not hasattr(view_function, '__self__'):
docs.register(view_function, blueprint=blueprint_name)
```

Is this good practice, or is there a better way to do this within `flask-apispec`?

Start with the flask-apispec registration documentation and the Flask app.view_functions behavior described in the issue. Determine whether blueprint routes can be registered without importing each view, and define the supported approach and its completion criteria; the issue does not name a target file or test.

Written by the indexing model from the issue text.