来自node.js内部模块的app.js调用函数？ [英] Call function of app.js from within module in node.js?

问题描述

假设我有以下app.js（显然 简化）：

  var express = require（'express'），
 app = express.createServer（）; 
 
 // include routes 
 require（'./ lib / routes'）（app）; 
 
 //一些随机函数
 var foo = function（）{
 return'bar'; 
}; 
 
 //另一个随机函数
 var foo2 = function（）{
 return'bar2'; 
}; 
  

然后我有路由模块：

  module.exports = function（app）{
 app.get（'/ some / route'，function（req，res）{
 var fooBar = foo （），
 fooBar2 = foo2（）; 
 
 res.end（fooBar + fooBar2）; 
}）; 
}; 
  

这显然不起作用，因为foo和foo2没有在模块中定义。有没有办法使这项工作，或至少是一个不同的模式，以更好地完成这些？

解决方案

你可以只是将这两个函数放在一个对象中，并将它们传递给routes.js的初始化。

  var express = require（'express'），
 app = express.createServer（）; 
 
 //一些随机函数
 var foo = function（）{
 return'bar'; 
}; 
 
 //另一个随机函数
 var foo2 = function（）{
 return'bar2'; 
}; 
 
 var fns = {foo：foo，foo2：foo2} 
 
 // include routes 
 require（'./ lib / routes'）（app，fns ）; 
  

路线：

  module.exports = function（app，fns）{
 app.get（'/ some / route'，function（req，res）{
 var fooBar = fns.foo ），
 fooBar2 = fns.foo2（）; 
 
 res.end（fooBar + fooBar2）; 
}）; 
}; 
  

这是怎么做到的。您也可以将它们包含在应用对象中。除了将它们传递给init函数之外，还可以导出这两个函数，并在routes.js中要求它们。

  var express = require（'express'），
 app = express.createServer（）; 
 
 //一些随机函数
 var foo = function（）{
 return'bar'; 
}; 
 
 //另一个随机函数
 var foo2 = function（）{
 return'bar2'; 
}; 
 
 module.exports = {foo：foo，foo2：foo2} 
 
 // include routes 
 require（'./ lib / routes'）（app， FNS）; 
  

路线：

  module.exports = function（app）{
 var fns = require（'../ app.js'）; 
 app.get（'/ some / route'，function（req，res）{
 var fooBar = fns.foo（），
 fooBar2 = fns.foo2（）; 
 
 res.end（fooBar + fooBar2）; 
}）; 
}; 
  

但是我不喜欢它的想法，因为它产生循环依赖。对他们没有什么好感。

Let's say I have the following app.js (obviously very simplified):

var express = require('express'),
    app = express.createServer();

// include routes
require('./lib/routes')(app);

// some random function
var foo = function() {
    return 'bar';
};

// another random function
var foo2 = function() {
    return 'bar2';
};

And then I have the routes module:

module.exports = function(app){
    app.get('/some/route', function(req, res){
        var fooBar = foo(),
            fooBar2 = foo2();

        res.end(fooBar + fooBar2);
    });
};

This obviously doesn't work since foo and foo2 weren't defined within the module. Is there a way to make this work, or at least a different pattern to better accomplish what this?

解决方案

Well you can just put these two functions in an object and pass them on the initialization of the routes.js .

var express = require('express'),
    app = express.createServer();

// some random function
var foo = function() {
    return 'bar';
};

// another random function
var foo2 = function() {
    return 'bar2';
};

var fns = {foo : foo, foo2: foo2}

// include routes
require('./lib/routes')(app, fns);

in routes:

module.exports = function(app, fns){
    app.get('/some/route', function(req, res){
        var fooBar = fns.foo(),
            fooBar2 = fns.foo2();

        res.end(fooBar + fooBar2);
    });
};

This is how would I do it. You can also include them in the app object. Beside passing them in init functions, you can also export those two functions and require them in routes.js.

var express = require('express'),
    app = express.createServer();

// some random function
var foo = function() {
    return 'bar';
};

// another random function
var foo2 = function() {
    return 'bar2';
};

module.exports = {foo : foo, foo2: foo2}

// include routes
require('./lib/routes')(app, fns);

in routes:

module.exports = function(app){
    var fns = require('../app.js');
    app.get('/some/route', function(req, res){
        var fooBar = fns.foo(),
            fooBar2 = fns.foo2();

        res.end(fooBar + fooBar2);
    });
};

But I don't like the idea of it, since it makes circular dependencies. Don't have any good feelings about them.

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