在Ajax請求之后，Django SessionWizardView從form_list中缺少當前步驟

Question

我有一個帶有條件額外步驟的SessionWizardView進程，在第一步結束時基本上要求'你想添加另一個人'，所以我的條件是通過檢查上一步的清理數據生成的;

def function_factory(prev_step):
    """ Creates the functions for the condition dict controlling the additional
    entrant steps in the process.

    :param prev_step: step in the signup process to check
    :type prev_step: unicode
    :return: additional_entrant()
    :rtype:
    """
    def additional_entrant(wizard):
        """
        Checks the cleaned_data for the previous step to see if another entrant
        needs to be added
        """
        # try to get the cleaned data of prev_step
        cleaned_data = wizard.get_cleaned_data_for_step(prev_step) or {}

        # check if the field ``add_another_person`` was checked.
        return cleaned_data.get(u'add_another_person', False)

    return additional_entrant

def make_condition_stuff(extra_steps, last_step_before_repeat):
    cond_funcs = {}
    cond_dict = {}
    form_lst = [
        (u"main_entrant", EntrantForm),
    ]

    for x in range(last_step_before_repeat, extra_steps):
        key1 = u"{}_{}".format(ADDITIONAL_STEP_NAME, x)
        if x == 1:
            prev_step = u"main_entrant"
        else:
            prev_step = u"{}_{}".format(ADDITIONAL_STEP_NAME, x-1)
        cond_funcs[key1] = function_factory(prev_step)
        cond_dict[key1] = cond_funcs[key1]
        form_lst.append(
            (key1, AdditionalEntrantForm)
        )

    form_lst.append(
        (u"terms", TermsForm)
    )

    return cond_funcs, cond_dict, form_lst

last_step_before_extras = 1
extra_steps = settings.ADDITIONAL_ENTRANTS

cond_funcs, cond_dict, form_list = make_condition_stuff(
    extra_steps,
    last_step_before_extras
)

我還有一個字典，用於存儲通過會話cookie訪問的密鑰后面的步驟數據，該會話cookie還包含用戶輸入的人員詳細信息列表。 在第一個表單之后，此列表呈現為一個選擇框＆on selection觸發對帶有kwargs的SessionWizard的Ajax調用，該kwargs觸發對返回JsonResponse的方法的調用;

class SignupWizard(SessionWizardView):
    template_name = 'entrant/wizard_form.html'
    form_list = form_list
    condition_dict = cond_dict
    model = Entrant
    main_entrant = None
    data_dict = dict()

    def get_data(self, source_step, step):
        session_data_dict = self.get_session_data_dict()
        try:
            data = session_data_dict[source_step].copy()
            data['event'] = self.current_event.id
            for key in data.iterkeys():
                if step not in key:
                    newkey = u'{}-{}'.format(step, key)
                    data[newkey] = data[key]
                    del data[key]
        except (KeyError, RuntimeError):
            data = dict()
            data['error'] = (
                u'There was a problem retrieving the data you requested. '
                u'Please resubmit the form if you would like to try again.'
            )

        response = JsonResponse(data)
        return response

    def dispatch(self, request, *args, **kwargs):
        response = super(SignupWizard, self).dispatch(
            request, *args, **kwargs
        )
        if 'get_data' in kwargs:
            data_id = kwargs['get_data']
            step = kwargs['step']
            response = self.get_data(data_id, step)

        # update the response (e.g. adding cookies)
        self.storage.update_response(response)
        return response

    def process_step(self, form):
        form_data = self.get_form_step_data(form)
        current_step = self.storage.current_step or ''
        session_data_dict = self.get_session_data_dict()

        if current_step in session_data_dict:
            # Always replace the existing data for a step.
            session_data_dict.pop(current_step)

        if not isinstance(form, TermsForm):
            entrant_data = dict()
            fields_to_remove = [
                'email', 'confirm_email', 'password',
                'confirm_password', 'csrfmiddlewaretoken'
            ]
            for k, v in form_data.iteritems():
                entrant_data[k] = v
            for field in fields_to_remove:
                if '{}-{}'.format(current_step, field) in entrant_data:
                    entrant_data.pop('{}-{}'.format(current_step, field))
                if '{}'.format(field) in entrant_data:
                    entrant_data.pop('{}'.format(field))

            for k in entrant_data.iterkeys():
                new_key = re.sub('{}-'.format(current_step), u'', k)
                entrant_data[new_key] = entrant_data.pop(k)

            session_data_dict[current_step] = entrant_data
            done = False
            for i, data in enumerate(session_data_dict['data_list']):
                if data[0] == current_step:
                    session_data_dict['data_list'][i] = (
                        current_step, u'{} {}'.format(
                            entrant_data['first_name'],
                            entrant_data['last_name']
                        )
                    )
                    done = True

            if not done:
                session_data_dict['data_list'].append(
                    (
                        current_step, u'{} {}'.format(
                            entrant_data['first_name'],
                            entrant_data['last_name']
                        )
                    )
                )

        return form_data

如果您在不觸發Ajax調用的情況下單步執行表單，則表單將提交，條件dict將按預期運行。 但是，如果觸發Ajax並將數據返回到表單，則一旦提交表單，會話數據就會消失。 有沒有辦法改變我的設置方式，以便get_data()可以將數據返回到頁面，而不會破壞會話？

我已經在開發服務器cached_db SESSION_ENGINE設置為cached_db但是我遇到了一個問題，即當您提交第一個條件表單並且系統調用get_next_step()后跟get_next_step() get_form_list()並且條件檢查不再返回第一個條件因為current_step不再是form_list一部分，所以我留下了我的默認表單列表並引發了ValueError 。

因此，回顧一下，我逐步瀏覽我的第一個表單，使用'add_another_person'字段觸發第一個條件表單，該字段按預期呈現表單，此時form_list如下所示;

form_list   
    u'main_entrant' <class 'online_entry.forms.EntrantForm'>
    u'additional_entrant_1' <class 'online_entry.forms.EntrantForm'>
    u'terms' <class 'online_entry.forms.TermsForm'>

但是一旦additional_entrant_1觸發Ajax方法，然后提交， form_list運行條件dict並且看起來像這樣;

form_list   
    u'main_entrant' <class 'online_entry.forms.EntrantForm'>
    u'terms' <class 'online_entry.forms.TermsForm'>

這可能是會話存儲或會話變為無效的問題嗎？

Answer 1

我總是忽略這個簡單的解釋。

SessionWizardView的get()請求重置存儲，我正在制作的Ajax調用作為get請求命中視圖，重置存儲，但也傳回我的信息。

因此，通過簡單覆蓋get()方法，我已經解決了這個問題;

def get(self, request, *args, **kwargs):
    if 'get_data' in kwargs:
        data_id = kwargs['get_data']
        step = kwargs['step']
        response = self.get_data(data_id, step)
    else:
        self.storage.reset()

        # reset the current step to the first step.
        self.storage.current_step = self.steps.first
        response = self.render(self.get_form())
    return response