As 2.0 is a major version bump, you can expect some breaking changes from Connexion 1.5.3.
- You can now use openapi 3 specifications
- Swagger UI is now optional, and can be installed with `pip install connexion[swagger-ui]`
- App and Api options must be provided through the "options" argument (``old_style_options`` have been removed).
- You must specify a form content-type in 'consumes' in order to consume form data.
- The `Operation` interface has been formalized in the `AbstractOperation` class.
- The `Operation` class has been renamed to `Swagger2Operation`.
- Array parameter deserialization now follows the Swagger 2.0 spec more closely.
In situations when a query parameter is passed multiple times, and the collectionFormat is either csv or pipes, the right-most value will be used.
For example, `?q=1,2,3&q=4,5,6` will result in `q = [4, 5, 6]`.
The old behavior is available by setting the collectionFormat to `multi`, or by importing `decorators.uri_parsing.AlwaysMultiURIParser` and passing `parser_class=AlwaysMultiURIParser` to your Api.
- The spec validator library has changed from `swagger-spec-validator` to `openapi-spec-validator`.
- Errors that previously raised `SwaggerValidationError` now raise the `InvalidSpecification` exception.
All spec validation errors should be wrapped with `InvalidSpecification`.
- Support for nullable/x-nullable, readOnly and writeOnly/x-writeOnly has been added to the standard json schema validator.
- Custom validators can now be specified on api level (instead of app level).
- Added support for basic authentication and apikey authentication
- If unsupported security requirements are defined or ``x-tokenInfoFunc``/``x-tokenInfoUrl`` is missing, connexion now denies requests instead of allowing access without security-check.
- Accessing ``connexion.request.user`` / ``flask.request.user`` is no longer supported, use ``connexion.context['user']`` instead