如何在django-viewflow中连接两个流

时间:2019-02-08 14:19:48

标签: django-viewflow

我正在使用django-viewflow来跟踪复杂的业务流程。为了避免使用冗长的Flow类和flows.py文件,我希望将一个流提供给另一个流。这可能吗?

我尝试了以下代码,但是Python引发了NotImplemented异常。

class SecondFlow(Flow):
    process_class = SecondProcess
    start = (...)

class FirstFlow(Flow):
    process_class = FirstProcess
    start = (
        flow.Start(
            CreateProcessView,
            fields=['foo']
        ).Next(SecondFlow.start)
    )

如果将FirstFlow路由到SecondFlow的开头,那就太好了。

编辑:我尝试使用提供的建议和文档,但是出现以下错误:'StartFunction'对象没有属性'prepare'

下面是我的新代码。

from viewflow import flow, frontend
from viewflow.base import this, Flow
from viewflow.flow.views import CreateProcessView, UpdateProcessView

from .models import FirstProcess, SecondProcess

@frontend.register
class SecondFlow(Flow):
    process_class = SecondProcess
    start = flow.StartFunction(this.create_flow
            ).Next(this.enter_text)

    def create_flow(self, activation, **kwargs):
        activation.prepare()
        activation.done()

    enter_text = (
        flow.View(
            UpdateProcessView,
            fields=['text']
        ).Next(this.end)
    )

    end = flow.End()


@frontend.register
class FirstFlow(Flow):
    process_class = FirstProcess

    start = (
        flow.Start(
            CreateProcessView,
            fields=['text']
        ).Next(this.initiate_second_flow)
    )

    initiate_second_flow = (
        flow.Handler(this.start_second_flow
        ).Next(this.end)
    )

    def start_second_flow(self, activation):
        SecondFlow.start.run()

    end = flow.End()

第二次修改:在将装饰器添加到SecondFlow的create_flow方法中后,此方法才起作用。

from django.utils.decorators import method_decorator
...

@frontend.register
class SecondFlow(Flow):
    process_class = SecondProcess
    start = flow.StartFunction(this.create_flow
            ).Next(this.enter_text)

    @method_decorator(flow.flow_start_func)
    def create_flow(self, activation, **kwargs):
        activation.prepare()
        activation.done()

...

1 个答案:

答案 0 :(得分:1)

flow.Start是用于由用户调用并创建过程的“开始”视图的任务。 View可能具有某些逻辑,通常,该逻辑依赖于request数据。因此,除了通过浏览器访问URL之外,您无法在其他地方调用flow.StartView和flow.View。

要以编程方式激活某些流程,请使用以下流程。StartFunction-http://docs.viewflow.io/viewflow_core_node.html#viewflow.nodes.StartFunction

要从其他流执行它,可以使用flow.Handler-http://docs.viewflow.io/viewflow_core_node.html#viewflow.nodes.Handler