我試圖在node.js中將findTitleLatestRev函數改爲lambda。 這用於貓鼬來定義模式的方法。 前:在node.js上使用lambda不起作用
RevisionSchema.statics.findTitleLatestRev = function(title, callback){
return this.find({'title':title})
.sort({'timestamp':-1})
.limit(1)
.exec(callback);
};
調用它在:
module.exports.getLatest=function(req,res){
let title = req.query.title;
Revision.findTitleLatestRev(title, (err,result)=>{
if (err) console.log('Cannot find ' + title + "'s latest revision!");
console.log(result);
revision = result[0];
res.render('revision.pug',{title: title, revision:revision});
});
};
改變之前,它的工作很好。我將其更改爲:
`RevisionSchema.statics.findTitleLatestRev = (title, callback)=>
{this.find({'title':title})
.sort({'timestamp':-1})
.limit(1).
exec(callback)};`
導致的錯誤:
`TypeError: this.find is not a function
at Function.RevisionSchema.statics.findTitleLatestRev (/home/tung/Documents/node/nodejs-labs/app/models/revision.js:25:8)
at module.exports.getLatest (/home/tung/Documents/node/nodejs-labs/app/controllers/revision.server.controller.js:24:14)
at Layer.handle [as handle_request] (/home/tung/Documents/node/nodejs-labs/node_modules/express/lib/router/layer.js:95:5)
at next (/home/tung/Documents/node/nodejs-labs/node_modules/express/lib/router/route.js:137:13)
at Route.dispatch (/home/tung/Documents/node/nodejs-labs/node_modules/express/lib/router/route.js:112:3)
at Layer.handle [as handle_request] (/home/tung/Documents/node/nodejs-labs/node_modules/express/lib/router/layer.js:95:5)
at /home/tung/Documents/node/nodejs-labs/node_modules/express/lib/router/index.js:281:22
at Function.process_params (/home/tung/Documents/node/nodejs-labs/node_modules/express/lib/router/index.js:335:12)
at next (/home/tung/Documents/node/nodejs-labs/node_modules/express/lib/router/index.js:275:10)
at Function.handle (/home/tung/Documents/node/nodejs-labs/node_modules/express/lib/router/index.js:174:3)
at router (/home/tung/Documents/node/nodejs-labs/node_modules/express/lib/router/index.js:47:12)
at Layer.handle [as handle_request] (/home/tung/Documents/node/nodejs-labs/node_modules/express/lib/router/layer.js:95:5)
at trim_prefix (/home/tung/Documents/node/nodejs-labs/node_modules/express/lib/router/index.js:317:13)
at /home/tung/Documents/node/nodejs-labs/node_modules/express/lib/router/index.js:284:7
at Function.process_params (/home/tung/Documents/node/nodejs-labs/node_modules/express/lib/router/index.js:335:12)
at next (/home/tung/Documents/node/nodejs-labs/node_modules/express/lib/router/index.js:275:10
)`
find在哪裏定義?你能粘貼全班嗎?如果find是貓鼬方法,那麼它就不會工作。 – kimy82
'findTitleLatestRev'函數用於mongoose模塊中以定義模式方法。 '發現'是在貓鼬或mongoDB的方法 –
是的。但是,在使用lambda時,'this'將是您定義靜態而不是mongoose模式的類。如果你想使用lambda,你應該改變'this',像_this.revisionModel.find(..._ – kimy82