Question

如何“宣传”我自己的功能（位于另一个目录中）？这是我的代码：

// app.js

// include database
var mongo = require('./mongo');
var promise = require('bluebird');
var u = require('./util.js');
var mongo.connect = promise.promisify(require(mongo.connect));

// connect to database

var ago = new Date(new Date()-60000); // 10m ago
var scope = {size:0.01};

mongo.connect()
.then(
  mongo.endor.mapReduceAsync(u.mapTile, u.reduceTile,{
  out: {replace:'deathstar'}, scope:scope,
  query: {time:{$gte:ago}}, finalize:u.finalTile}))
.then(deathstar.find({},{fields:{_id:0, value: 1}})
  .toArray(function(err, docs){
    endor.insertAsync(_.map(docs, function(doc){return doc.value;}),{w:1});
  )
);

这是另一个文件

// mongo.js

var promise = require('bluebird');
var mongodb = require('mongodb');
var MongoClient = mongodb.MongoClient;
promise.promisifyAll(mongodb);

module.exports.connect = promise.method(function(){
  // database environment
  var database;
    if (process.env.NODE_ENV == 'production'){database = pro;}
    else{database = database = dev;}
  module.exports.database = database;

  // connect to database
  return MongoClient.connectAsync(database)
    .then(function(db){
      module.exports.db = db;
      promise.all([
        db.createCollectionAsync('hoth', {w:1})
          .then(function(collection){
            collection.ensureIndexAsync()
              .then(function(index){
                module.exports.hoth = collection;
                console.log(index+' hoth');
              });
          }),
        db.createCollectionAsync('endor', {w:1})
          .then(function(collection){
            collection.ensureIndexAsync({})
              .then(function(index){
                module.exports.endor = collection;
                console.log(index+' endor');
              });
          }),
        db.createCollectionAsync('alderaan', {w:1})
          .then(function(collection){
            collection.ensureIndexAsync({time:-1, location:'2dsphere'})
              .then(function(index){
                module.exports.endor = collection;
                console.log(index+' alderaan');
              });
          })
      ]).then(function(){callback(null);});
    }
  );
});

这是错误

/Users/Josh/Development/xWing/app.js:12
mongo.connectAsync()
  ^
TypeError: Object #<Object> has no method 'connectAsync'

Answer 1

Promise带回了同步代码的品质。

鉴于您的API已经被承诺 - 您只需从您的函数返回一个承诺，然后使用它。

module.exports.connect = Promise.method(function(){
    // do a bunch of stuff
    return mongo.connectAsync().then(...
});

注意Promise.method位并不是必需的，它只是将抛出的错误变成拒绝，以便让您保持安全，并确保您返回一个承诺，这是它的最佳做法并保护您免受意外事故的影响

我如何宣传自己的功能？

1 个答案: