drf之版本控制

drf总流程链接

https://www.cnblogs.com/daviddd/p/11918405.html

drf之版本控制

'''
承接rest_framework主流程5.1内容，
视图函数在rest_framework的views.py文件中
drf版本控制，需要APIView基类的静态属性
'''

class APIView(View):
    
    # settings配置文件
    versioning_class = api_settings.DEFAULT_VERSIONING_CLASS

    settings = api_settings
    schema = DefaultSchema()
    
    
def initial(self, request, *args, **kwargs):
    
    # 5.1，版本信息
    # Determine the API version, if versioning is in use.
    version, scheme = self.determine_version(request, *args, **kwargs)
    request.version, request.versioning_scheme = version, scheme
    
    
# 5.12，执行determine_version函数
def determine_version(self, request, *args, **kwargs):
    """
    If versioning is being used, then determine any API version for the
    incoming request. Returns a two-tuple of (version, versioning_scheme)
    """
    
    if self.versioning_class is None:
        return (None, None)
        
        
        
    # 5.13
    '''
    根据settings配置文件中或者自定义的versioning_class，实例化对象URLPathVersioning()
    from rest_framework.versioning import URLPathVersioning
    '''
    scheme = self.versioning_class()
    
    
    
    # 5.14
    
    '''
    执行类URLPathVersioning中的 determine_version()方法，
    在这里获取到scheme就是api_settings.DEFAULT_VERSIONING_CLASS,
    系统默认版本控制类，那scheme.determine_version(request, *args, kwargs) 
    就是该类下的一个方法查看rest_framework库的一个自带类中的determine_version方法
    '''
    
    return (scheme.determine_version(request, *args, **kwargs), scheme)
    
    
    
    
    # 5.15，
    '''
    这是URLPathVersioning类中的determine_version()方法
    返回的是版本号。于是version, scheme分别是版本号和一个版本控制类，
    并分别赋值给request对象的version, versioning_scheme属性
    '''
    def determine_version(self, request, *args, **kwargs):
        version = kwargs.get(self.version_param, self.default_version)
        if version is None:
            version = self.default_version

        if not self.is_allowed_version(version):
            raise exceptions.NotFound(self.invalid_version_message)
        return version