1 

     2 Managing requests

     3 -----------------

     4 

     5 PyAMS_utils package provides some useful functions to handle requests.

     6 

     7 The "check_request" function can be used when you have to be sure that a request is active in

     8 the current execution thread; if no "real" request is active, a new one is created:

     9 

    10     >>> from pyams_utils.request import query_request, check_request

    11     >>> request = query_request()

    12     >>> request is None

    13     True

    14     >>> request = check_request()

    15     >>> request

    16     <PyAMSRequest at ... GET http://localhost/>

    17 

    18 If a new request is created "from scratch", it's registry is assigned to global registry:

    19 

    20     >>> request.registry

    21     <Registry global>

    22 

    23 A request context can be used to activate a request into execution thread:

    24 

    25     >>> from pyramid.threadlocal import RequestContext

    26     >>> with RequestContext(request) as context_request:

    27     ...     context_request is request

    28     True

    29     >>> with RequestContext(request):

    30     ...     context_request = check_request()

    31     ...     context_request is request

    32     True

    33 

    34 Requests can now support annotations to set and retrieve any information to a given request:

    35 

    36     >>> from zope.annotation.interfaces import IAttributeAnnotatable, IAnnotations

    37     >>> from zope.annotation.attribute import AttributeAnnotations

    38     >>> from pyams_utils.registry import get_global_registry

    39     >>> registry = get_global_registry()

    40     >>> registry.registerAdapter(AttributeAnnotations, (IAttributeAnnotatable, ), IAnnotations)

    41 

    42     >>> from pyams_utils.request import get_request_data, set_request_data

    43     >>> set_request_data(request, 'test', 'This is request data')

    44     >>> get_request_data(request, 'test')

    45     'This is request data'

    46 

    47 Annotations can be used to automatically reify a given property into request annotations:

    48 

    49     >>> from pyams_utils.request import request_property

    50     >>> class RequestPropertyTestClass(object):

    51     ...

    52     ...     @request_property(key='My property')

    53     ...     def my_property(self):

    54     ...         print("This is my property")

    55     ...         return 1

    56     ...

    57     >>> with RequestContext(request):

    58     ...     instance = RequestPropertyTestClass()

    59     ...     instance.my_property()

    60     This is my property

    61     1

    62 

    63 As property value is cached into request annotations, other property calls will just return

    64 cached value:

    65 

    66     >>> with RequestContext(request):

    67     ...     instance.my_property()

    68     1

    69 

    70 The "copy_request" function  is used to clone another request. All request methods and properties

    71 defined via "add_request_method()" are kept, as "registry" and "root" attributes:

    72 

    73     >>> from pyams_utils.request import copy_request

    74     >>> request2 = copy_request(request)

    75     >>> request2.registry is request.registry

    76     True

    77     >>> request2.root is None

    78     True