node.js - app.use() 需要中间件函数 app.use( seneca.export ('web' ) );

Question

我是 seneca 的菜鸟，我只是想运行 Developing Microservices with Node js 中的示例代码，它说:

var seneca = require('seneca')();

seneca.add('role:api,cmd:bazinga',function(args,done){
    done(null,{bar:"Bazinga!"});
});

seneca.act('role:web',{use:{
    prefix: '/my-api',
    pin: {role:'api',cmd:'*'},
    map:{
    bazinga: {GET: true}
    }
    }})

var express = require('express');
var app = express();

app.use( seneca.export('web') ); // <<<<<< this line might be the cause 
app.listen(3000);

但我收到一条错误消息:

TypeError: app.use() requires middleware functions    at EventEmitter.use (/home/oem/node_modules/express/lib/application.js:209:11)    at Object. (/home/oem/Documents/seneca/app.js:7:8)    at Module._compile (module.js:409:26)    at Object.Module._extensions..js (module.js:416:10)    at Module.load (module.js:343:32)    at Function.Module._load (module.js:300:12)    at Function.Module.runMain (module.js:441:10)    at startup (node.js:139:18)    at node.js:974:3

Also I tried to run another sample code copied from the web, I'm sorry I just can find the link. But I just copied, pasted and tried to run and I got the same error. I'm thinking this is more of a setup issue?

edit

I'm still trying to play with this. The way I understand this is that on app.use line, basically I'm just calling the seneca-web module. so what I did was

app.use(require('seneca-web'))

代替

app.use( seneca.export('web') )

然后我运行 node app.js，它运行了脚本，命令中没有错误。但是当试图从浏览器访问模块时，我收到错误消息，指出未找到 util 并指向 seneca web 文件，该文件实际上来自 seneca 的调用。现在我不确定现在该做什么

我试图将我必须的 Node 版本从 6.0 降低到 4.0，但仍然出现相同的错误

Answer 1

看看主要seneca.js file ，您会看到只有 transport 被列为默认插件(不是 web):

default_plugins: {
    transport: true
}

app.use(seneca.export('web')); 行因此传递 undefined 以表示为中间件，因此您遇到的错误。

您必须首先明确告诉 seneca 使用 web 插件并将您的 express 服务器作为参数。试试这个:

var Seneca  = require("seneca");
var Express = require("express");
var Web     = require("seneca-web");

var seneca = Seneca();
var server = Express();

var config = {
    routes:{
        prefix : "/my-api",
        pin: "role:api,cmd:*",
        map:{
            bazinga: {
                GET: true
            }
        }
    }
};

seneca.use(Web, { adapter: "express", context: server })
seneca.act("role:web", config);
seneca.add("role:api,cmd:bazinga", bazinga);

server.listen(3000);


function bazinga(args, done){

    done(null, {
        bar: "Bazinga!"
    });
}

调用 http://localhost:3000/my-api/bazinga在浏览器中产生{"bar":"Bazinga!"}