我正在研究Node.JS/Express应用程序。我使用Jade作为模板引擎。我正在经历一些奇怪的行为。Node.JS Express Promise Issue
我有一个模拟API,返回一个简单的数组到我的Jade模板。我从服务器的角度验证了API的作品。但是,每当我开始了我第一次去那个特定页面的服务器我收到一个错误
TypeError: Cannot read property 'length' of undefined
at routes.js:28:34
at Layer.handle [as handle_request] (E:\dev\code\javascript\ps_resume_express\node_modules\express\lib\router\layer.js:95:5)
at next (E:\dev\code\javascript\ps_resume_express\node_modules\express\lib\router\route.js:131:13)
at Route.dispatch (E:\dev\code\javascript\ps_resume_express\node_modules\express\lib\router\route.js:112:3)
at Layer.handle [as handle_request] (E:\dev\code\javascript\ps_resume_express\node_modules\express\lib\router\layer.js:95:5)
at E:\dev\code\javascript\ps_resume_express\node_modules\express\lib\router\index.js:277:22
at Function.process_params (E:\dev\code\javascript\ps_resume_express\node_modules\express\lib\router\index.js:330:12)
at next (E:\dev\code\javascript\ps_resume_express\node_modules\express\lib\router\index.js:271:10)
at Function.handle (E:\dev\code\javascript\ps_resume_express\node_modules\express\lib\router\index.js:176:3)
at router (E:\dev\code\javascript\ps_resume_express\node_modules\express\lib\router\index.js:46:12)
出现这种情况我每次启动启动服务器时。但是,只要它继续运行,后续调用就可以工作,并且页面可以正确呈现。
这里是我的路线的方法是
router.get('/skills', (req, res) => {
console.log('received request for skills');
resumeAPI.getAllSkills().then((skills) => {
console.log("inside then skills length " + skills.length);
properties.skills = skills;
console.log("inside then properties.skills length " + properties.skills.length);
});
console.log("outside promise skills length " + properties.skills.length);
properties.heading = 'Skills';
res.render('skills', properties)
});
我把在执行console.log线,试图捕捉到正在发生的事情。
我的API方法如下
class ResumeApi {
static getAllSkills() {
return new Promise((resolve, reject) => {
console.log("from api skills " + skills.length);
resolve(skills);
});
}
}
什么可能我是做错了什么?
'res.render( '技能',属性)'应该是里面'then'声明。 – Hosar