问题描述
我正在创建一个express.js应用程序作为团队项目的一部分。我是一名javascipt新手,但是最终任务落在了我身上。相关代码的目的是使用一些用户定义的选项,在单击按钮时运行脚本,然后显示一个新页面并显示在结果页面上生成的报告的链接。无论出于何种原因,在应用程序启动后第一次都无法使用此功能,但是如果您返回并重试,它将可以使用。我曾以为有一个同步问题,也许有,但是似乎也存在数组变量未传递给pug的问题。数周来,我一直在桌子上猛撞,并向我的教授(我们俩都不是CS人士)寻求帮助,但没有运气。请帮忙。
这是文件开头的应用变量,配置等:
// index.js
/**
* required External Modules
*/
const express = require("express");
const path = require("path");
const shell = require("shelljs");
const fs = require("fs");
/**
* App Variables
*/
const app = express();
const port = process.env.PORT || "8000";
var ipAddresses;
var ipAddressesLink;
/**
* App Configuration
*/
app.set("views",path.join(__dirname,"views"));
app.set("view engine","pug");
app.use(express.static(path.join(__dirname,"public")));
app.use(express.static(path.join(__dirname,"reports/html")));
//code to make html forms work
var bodyParser = require('body-parser');
app.use(bodyParser.urlencoded({ extended: false }));
以下是不断使我失望的相关路线:
//Run script when post is rec'd from root and send to results page
app.post("/",(req,res) => {
//take values and create complete command for Astrum script
var commandString = 'bash /home/astrum/Main/Astrum.sh -s ' + req.body.speed + ' -h ' + req.body.host + ' -u ' + req.body.username + ' -p ' + req.body.password;
var pathToReports = './reports/html';
runScript(commandString);
readFolder(pathToReports);
renderPage();
//Iterate thru filenames to create arrays for links and link labels
function readFolder(pathValue) {
fs.readdir(pathValue,(err,files) => {
console.log(files)
//variable & method for links to html records pages
ipAddressesLink = files;
console.log(ipAddressesLink);
//variable and method to remove file extension for link labels in pug
ipAddresses = files.map(removeExtension);
});
}
//function to remove last five characters of each element
function removeExtension(value) {
return value.substring(0,value.length - 5);
};
//function to render the page
function renderPage() {
res.render("results",{ipAddressesLink,ipAddresses,title: 'Results'});
}
//function to execute command in shell
function runScript(value) {
shell.exec(value);
}
//show array on console for debugging
console.log("type of record is: " + typeof ipAddressesLink);
console.log(ipAddressesLink);
console.log(ipAddresses);
res.end();
});
以下是结果页面的pug模板,该模板引发了错误,显然是正在进行的工作:
extends layout
block layout-content
div.View
div.Message
div.Title
h1 Astrum Network Analysis
div.Body
div.multiple-group
h3 heading
select(id='whitelist',name='whitelist' size='6' multiple)
option(value="volvo") Volvo
option(value="saab") Saab
option(value="fiat") Fiat
option(value="audi") Audi
option(value="bmw") BMW
div.form-group
label(for='whitelistButton')
input(type='submit' value='Whitelist Ports')
h3 Hosts Found:
ul
each val,index in ipAddressesLink
li: a( href = val ) #{ipAddresses[index]}
这是我收到的错误消息:
TypeError: /home/astrum/Main/astrumApp/views/results.pug:36
34| ul
35|
> 36| each val,index in ipAddressesLink
37|
38| li: a( href = val ) #{ipAddresses[index]}
39|
Cannot read property 'length' of undefined
at eval (eval at wrap (/home/astrum/Main/astrumApp/node_modules/pug-runtime/wrap.js:6:10),<anonymous>:93:32)
at eval (eval at wrap (/home/astrum/Main/astrumApp/node_modules/pug-runtime/wrap.js:6:10),<anonymous>:116:4)
at template (eval at wrap (/home/astrum/Main/astrumApp/node_modules/pug-runtime/wrap.js:6:10),<anonymous>:119:7)
at Object.exports.renderFile (/home/astrum/Main/astrumApp/node_modules/pug/lib/index.js:452:38)
at Object.exports.renderFile (/home/astrum/Main/astrumApp/node_modules/pug/lib/index.js:442:21)
at View.exports.__express [as engine] (/home/astrum/Main/astrumApp/node_modules/pug/lib/index.js:491:11)
at View.render (/home/astrum/Main/astrumApp/node_modules/express/lib/view.js:135:8)
at tryRender (/home/astrum/Main/astrumApp/node_modules/express/lib/application.js:640:10)
at Function.render (/home/astrum/Main/astrumApp/node_modules/express/lib/application.js:592:3)
at ServerResponse.render (/home/astrum/Main/astrumApp/node_modules/express/lib/response.js:1012:7)
解决方法
您应该使用$ java -version
openjdk version "15" 2020-09-15
OpenJDK Runtime Environment (build 15+36-1562)
OpenJDK 64-Bit Server VM (build 15+36-1562,mixed mode,sharing)
$ java -classpath . foo.Foo
<?xml version="1.0" encoding="UTF-8"?><gazonk:xyzzy xmlns:gazonk="urn:foo:bar">
</gazonk:xyzzy>
!我确定fs.readdirSync
函数中的fs.readdir
用完了您预期的处理顺序:
readFolder
,
尝试更改:
//function to render the page
function renderPage() {
res.render("results",{ipAddressesLink,ipAddresses,title: 'Results'});
}
收件人:
//function to render the page
function renderPage() {
res.render("results",{ipAddressesLink: ipAddressesLink,ipAddresses: ipAddresses,title: 'Results'});
}