NodeJS找不到自定义模块

Question

I am trying to export a module to my routes file.

My file tree goes like

routes.js
app.js
controllers/users.js
            posts.js

on my app.js I exported var route = require('./routes'); and that works. now on my routes.js I tried to export require('./controllers'); .

But it keeps telling me that it cannot find module controllers .

Doing this works:

require('./controllers/users')

But I am trying to follow expressjs sample initial projects format. And it is bugging me because the example of expressjs shows: (express routes is a folder)

var routes = require('./routes');

and loads it like

app.get('/', routes.index);

with no error. and that ./routes is a folder. I am just following the same principle.

Answer 1

If you try to require a directory, it expects there to be an index.js file in that directory. Otherwise, you have to simply require individual files: require('./controllers/users') . Alternatively, you can create an index.js file in the controllers directory and add the following:

module.exports.users = require('./users');
module.exports.posts = require('./posts');

and then import: var c = require('./controllers'); . You can then use them via c.users and c.posts .

Answer 2

You have to understand how require() works.

In your case it fails to find a file named controller.js so it assumes it's a directory and then searches for index.js specifically. That is why it works in the express example.

For your usecase you can do something like this -

var controllerPath = __dirname + '/controllers';
fs.readdirSync(controllerPath).forEach(function(file) {
    require(controllerPath + '/' + file);
});

Answer 3

From: http://nodejs.org/api/modules.html

LOAD_AS_DIRECTORY(X)

1. If X/package.json is a file, a. Parse X/package.json, and look for "main" field. b. let M = X + (json main field) c. LOAD_AS_FILE(M)
2. If X/index.js is a file, load X/index.js as JavaScript text. STOP
3. If X/index.node is a file, load X/index.node as binary addon. STOP

So, if a directory has an index.js, it will load that.

Now, look @ expressjs

http://expressjs.com/guide.html

create : myapp/routes

create : myapp/routes/index.js

Taking some time to really read how modules work is time well spent. Read here