Add option to exclude OPTIONS requests

These changes add a new optional parameter called `document_options`
to the FlaskApiSpec constructor that will exclude OPTIONS requests
from the swagger specification if set to `False`.

Flask automatically generates OPTIONS requests for each route. There are
cases, such as when using CORS, where one would want these OPTIONS
requests to be generated but do not want to have them in their swagger
docs.

My line of reasoning for wanting to exclude these is: My API users
will never explicitly make an OPTIONS request. The browser will
automatically send a pre-flight OPTIONS request when making a
cross-origin request, and I want to have OPTIONS endpoints in order
to support that, but I don't want to have this functionality adding
a bunch of endpoints to my swagger docs which will largely be ignored
by users.

flask_apispec/apidoc.py

@@ -15,9 +15,10 @@
 
 class Converter(object):
 
-    def __init__(self, app, spec):
+    def __init__(self, app, spec, document_options):
         self.app = app
         self.spec = spec
+        self.document_options = document_options
         try:
             self.marshmallow_plugin = next(
                 plugin for plugin in self.spec.plugins
@@ -39,13 +40,16 @@ def convert(self, target, endpoint=None, blueprint=None, **kwargs):
     def get_path(self, rule, target, **kwargs):
         operations = self.get_operations(rule, target)
         parent = self.get_parent(target, **kwargs)
+        excluded_methods = {'head'}
+        if not self.document_options:
+            excluded_methods.add('options')
         return {
             'view': target,
             'path': rule_to_path(rule),
             'operations': {
                 method.lower(): self.get_operation(rule, view, parent=parent)
                 for method, view in six.iteritems(operations)
-                if method.lower() in (set(VALID_METHODS) - {'head'})
+                if method.lower() in (set(VALID_METHODS) - excluded_methods)
             },
         }
 

flask_apispec/extension.py

@@ -35,14 +35,17 @@ def get_pet(pet_id):
 
     :param Flask app: App associated with API documentation
     :param APISpec spec: apispec specification associated with API documentation
+    :param bool document_options: Whether or not to include
+        OPTIONS requests in the specification
     """
 
-    def __init__(self, app=None):
+    def __init__(self, app=None, document_options=True):
         self._deferred = []
         self.app = app
         self.view_converter = None
         self.resource_converter = None
         self.spec = None
+        self.document_options = document_options
 
         if app:
             self.init_app(app)
@@ -53,8 +56,10 @@ def init_app(self, app):
                     make_apispec(self.app.config.get('APISPEC_TITLE', 'flask-apispec'),
                                  self.app.config.get('APISPEC_VERSION', 'v1'))
         self.add_swagger_routes()
-        self.resource_converter = ResourceConverter(self.app, spec=self.spec)
-        self.view_converter = ViewConverter(app=self.app, spec=self.spec)
+        self.resource_converter = ResourceConverter(self.app,
+                                                    self.spec,
+                                                    self.document_options)
+        self.view_converter = ViewConverter(self.app, self.spec, self.document_options)
 
         for deferred in self._deferred:
             deferred()