Question

我正在快递上构建一个Node API，它接受GET请求并使用客户端提供的参数返回向其他API发出的GET请求的结果。

为了在添加更多API时保持控制器的精简，我想将控制器中的逻辑导出到单独的.js文件中，并将module.export这些函数重新导入，以便在控制器。这里的问题是导出的函数似乎在控制器中不可见。

下面粘贴的是代码之前和之后，以说明目前为止取得的进展。

app.js（之前） - 请参阅router.get（＆＃39; /＆＃39;）

var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');
var request = require('request');

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

var app = express();
var router = express.Router();

if ( app.get('env') === 'development') {
  var dotenv = require('dotenv');
  dotenv.load();
};

var prodAdv = require('./lib/prod-adv.js')

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

// uncomment after placing your favicon in /public
//app.use(favicon(path.join(__dirname, 'public', 'favicon.ico')));

app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));

app.use('/', routes);
app.use('/users', users);
app.use('/api', router);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  var err = new Error('Not Found');
  err.status = 404;
  next(err);
});

// error handlers

// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
  app.use(function(err, req, res, next) {
    res.status(err.status || 500);
    res.render('error', {
      message: err.message,
      error: err
    });
  });
}

// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
  res.status(err.status || 500);
  res.render('error', {
    message: err.message,
    error: {}
  });
});

router.get('/', function(req, res) {
  request('https://openapi.etsy.com/v2/listings/active?includes=Images&keywords=' + req.param('SearchIndex') + '&limit=100&api_key=' + process.env.ETSY_KEY, function(error, response, body) {
    res.header({'Access-Control-Allow-Origin': '*'});
    var data = JSON.parse(body);
    res.json(data);
  });
});

router.use('*', function(req, res, next) {
  res.header("Access-Control-Allow-Origin", "*");
  res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept, accept, authorization");
  next();
});


var server = app.listen(9876, function() {
var host = server.address().address;
var port = server.address().port;
  console.log('Example app listening at http://%s:%s',host,port);
});

module.exports = app;

此方法有效，返回JSON对象。但是，以下尝试导出代码的方法不起作用。

apiCaller.js

var express = require('express');
var app = express();
if ( app.get('env') === 'development' ) { var dotenv = require('dotenv'); dotenv.load(); };
var request = require('request');
var call, response;

var call = function(searchIndex) {
  return request('https://openapi.etsy.com/v2/listings/active?includes=Images&keywords=' + searchIndex + '&limit=100&api_key=' + process.env.ETSY_KEY, function(error, response, body) {
    response = JSON.parse(body);
  });
};

module.exports.response = response;
module.exports.call = call;

app.js（之后）

var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');
var squid = require('./lib/apiCaller.js');

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

var app = express();
var router = express.Router();

if ( app.get('env') === 'development') {
  var dotenv = require('dotenv');
  dotenv.load();
};

var prodAdv = require('./lib/prod-adv.js')

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

// uncomment after placing your favicon in /public
//app.use(favicon(path.join(__dirname, 'public', 'favicon.ico')));

app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));

app.use('/', routes);
app.use('/users', users);
app.use('/api', router);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  var err = new Error('Not Found');
  err.status = 404;
  next(err);
});

// error handlers

// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
  app.use(function(err, req, res, next) {
    res.status(err.status || 500);
    res.render('error', {
      message: err.message,
      error: err
    });
  });
}

// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
  res.status(err.status || 500);
  res.render('error', {
    message: err.message,
    error: {}
  });
});

router.get('/', function(req, res) {
  squid.call(req.param('SearchIndex'));
  res.header({'Access-Control-Allow-Origin': '*'});
  res.json(squid.response);
});

router.use('*', function(req, res, next) {
  res.header("Access-Control-Allow-Origin", "*");
  res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept, accept, authorization");
  next();
});


var server = app.listen(9876, function() {
var host = server.address().address;
var port = server.address().port;
  console.log('Example app listening at http://%s:%s',host,port);
});

module.exports = app;

现在在浏览器中发生的是200 OK，其响应正空。 console.logging响应返回未定义的对象。

Answer 1

您需要重写call函数才能进行回调，因为request(...)是异步的

var call = function(searchIndex, callback) {
    request('https://openapi.etsy.com/v2/listings/active?includes=Images&keywords=' + searchIndex + '&limit=100&api_key=' + process.env.ETSY_KEY, function(error, response, body) {
        if (!error && response.statusCode == 200) {
            return callback(null, JSON.parse(body));
        }
        callback('error');
    });
};

仅导出call功能，无需导出甚至使用response，也不需要此行

var call, response;

现在你还需要以不同的方式使用它

router.get('/', function(req, res) {
    res.header({'Access-Control-Allow-Origin': '*'});
    squid.call(req.param('SearchIndex'), function(err, data){
        if(!err) return res.json(data);
        res.json({error: err});
    });    
});

node / express - 导出控制器功能

1 个答案: