I have been having an issue with missing instances and nilClass errors when calling my routes. After delving around within the source it seems like the generate_method call basically creates a new method using the block of the initial method.

调用路由时,我遇到了丢失实例和nilClass错误的问题。在源代码中钻研之后,似乎generate_method调用基本上使用初始方法的块创建了一个新方法。

get "/" do
    @some_local_instance.do_something()
end

So in the above method there could very well be a local variable within that class called some_local_instance, however when the rote is actually evaluated it has no context as to where the method was defined, so it will fail.

所以在上面的方法中,很可能在该类中有一个名为some_local_instance的局部变量,但是当实际评估死记硬背时,它没有关于方法定义位置的上下文,因此它将失败。

The reason I ask is because as part of my script I have external classes which are loaded when Sinatra is loaded which register routes and when those routes are called I need to access some local variables on these classes. An example would be:

我问的原因是因为作为我的脚本的一部分,我有外部类,当加载Sinatra时加载哪些注册路由,当调用这些路由时,我需要访问这些类的一些局部变量。一个例子是:

class SomeRouteClass
    def initialize(sinatra, calculator)
        @calculator = calculator
        @sinatra = sinatra
    end

    def setup_routes
        @sinatra.get "/add" do
            return @calculator.add(1,1)
        end
    end
end

class Calculator
    def add(a,b)
        return a+b;
    end
end

sinatra = Sinatra.new
calculator = Calculator.new

routing_class = SomeRouteClass.new(sinatra, calculator)
routing_class.setup_routes

sinatra.run!

Forgive any spelling/syntax mistakes this is just a quick example, but as you can see a class registers routes and when that route is hit returns some value generated by an instance of the calculator it took when it was instantiated.

原谅任何拼写/语法错误这只是一个简单的例子,但正如你可以看到一个类注册路由以及当该路由被命中时返回一个由实例化它的计算器实例生成的值。

Problem I have is that in this example when I try and run the /add route it tells me that @calculator is a nilClass, and I believe it to be down to the way that Sinatra just takes the block of code without context. This seems fine for any simple template rendering, but if you need to do anything more fancy, or want to keep your code modular by not using statics and singletons you do not seem to have any way around this...

我遇到的问题是,在这个例子中,当我尝试运行/ add路由时,它告诉我@calculator是一个nilClass,我相信它是由Sinatra在没有上下文的情况下获取代码块的方式。对于任何简单的模板渲染来说这似乎都很好,但是如果你需要做更多花哨的事情,或者想要通过不使用静态和单例来保持代码模块化,那么你似乎没有办法解决这个问题......

Are my assumptions correct here? and if so is there any way to keep context as it feels like it is forcing me to write bad and hard to maintain code if I have to write everything as statics and singletons to interact from a route.

我的假设在这里是否正确?如果是这样的话,有任何方法可以保持上下文,因为如果我必须将所有东西都写成静态和单例来从路径进行交互,那么它就会迫使我编写糟糕且难以维护的代码。

== Edit ==

==编辑==

Have restructured the question and content to more accurately reflect the actual problem, now that I have a firmer understanding of the library.

重新构建了问题和内容,以更准确地反映实际问题,现在我对图书馆有了更深刻的理解。

3 个解决方案

def setup_routes
    calculator = @calculator
    @sinatra.get "/add" do
        return calculator.add(1,1)
    end
end

class SomeRouteClass
    def initialize(sinatra, calculator)
        @calculator = calculator
        @sinatra = sinatra
    end

    def calculator
        @calculator
    end

    def setup_routes
        @sinatra.get "/add" do
            return calculator.add(1,1)
        end
    end
end