从其他2个js文件中调用两次js文件会导致找不到该函数

I have four JavaScript files as follows:

我有四个JavaScript文件如下:

API.js

var controller = require('./Controller');

var apifunction = new function(){
controller.a(function(result) {
   console.log("result: " + result)
})}

Controller.js

var bll = require('./BLL.js');

module.exports = 
{
   a: function(callback){
      bll.b(function(result){
        callback(result);
      })
   }

  c: function(callback){
     callback(result);
     }
  }
}

BLL.js

var controller = require('./Controller.js');

module.export = 
{

  b: function(callback){
    controller.c(function(result){
      callback(result);
    })
  }

}

So the API function that calls the a function in the controller which again calls the b function in the BLL.

因此API函数调用控制器中的一个函数,该函数再次调用BLL中的b函数。

In the BLL it calls the c function in the controller again but then I get an Error: controller.c is not a function.

在BLL中它再次调用控制器中的c函数,但后来我得到一个错误:controller.c不是一个函数。

Any ideas?

2 个解决方案

#1

Controller.js and BLL.js "require" each other, that's the problem, one will get a empty module(placeholder).

Controller.js和BLL.js彼此“需要”,这就是问题,一个人将获得一个空模块(占位符)。

You can refactor it, remove the bidirectional "require", such as pass one module as parameter to the other.

您可以重构它,删除双向“require”,例如将一个模块作为参数传递给另一个。

#2

Consider seperating out the function controller.c into a seperate file...E.g. commonC.js

考虑将函数controller.c分离成一个单独的文件...例如。 commonC.js

CommonC.js

module.exports = 
{
  c: function(callback){
     callback(result);
     }
  }
}

Controller.js

var bll = require('./BLL.js');

module.exports = 
{
   a: function(callback){
      bll.b(function(result){
        callback(result);
      })
   }
}

BLL.js

var controller = require('./Controller.js');
var commonC = require('./CommonC.js');

module.export = 
{

  b: function(callback){
    commonC.c(function(result){
      callback(result);
    })
  }
}

Alternatively, if refactoring is not an option (you should refactor), you can put the require inside the function so that it executes when the function is invoked.

或者,如果重构不是一个选项(你应该重构),你可以将require放在函数中,以便在调用函数时执行。

Controller.js

module.exports = 
{
   a: function(callback){
      var bll = require('./BLL.js');
      bll.b(function(result){
        callback(result);
      })
   }

  c: function(callback){
     callback(result);
     }
  }
}