Stuck on my first attempt at a basic app. Scraper.js scrapes a URL and writes the returned array to the document obj when run alone in console, so that part works. Now all I want is an Express server to run the script whenever I open localhost:3000 but not sure how to do so.
|node_modules
|package.json
|public
|-index.html (boilerplate HTML. Not importing anything)
|src
|-scraper.js
|index.js
index.js:
var scraperjs = require('scraperjs');
var express = require('express');
var app = express()
app.use(express.static(__dirname + '/public'));
app.listen(3000);
--
scraper.js:
scraperjs.StaticScraper.create('https://examplesite.com/')
.scrape(function($) {
return $(".entry-content p").map(function() {
var content = $(this).html();
return content
}
}).get();
})
.then(function(data) {
... // eventually will write the items returned from the data array to div's
}
});
You need to export the scraperjs function using module.exports = functionName() as the last line in scraper.js.
Your require in index.js needs to factor in the path location for scraper.js. So:
var scraperjs = require('./src/scraperjs');
Here is a one that i've coded with promises, and also using a global variable which is daNews
var scraperjs = require('scraperjs');
var express = require('express');
var app = express();
app.use(express.static(__dirname + '/public'));
var url = 'https://news.ycombinator.com/';
var daNews;
function myScraper(){
return new Promise((resolve, reject) => {
scraperjs.StaticScraper.create(url)
.scrape(function($) {
return $(".title a").map(function() {
return $(this).text();
}).get();
})
.then(function(news) {
daNews = news;
resolve('done');
})
});
}
app.get('/', function(req, res){
async function m1(){
var x = await myScraper();
if(x == 'done'){
res.send(daNews);
}else{
console.log('err');
}
}
m1();
})
app.listen(3000);
Related
I am building NodeJS code that listens to requests from specific ports and returns a response to it, here is the main code:
module.exports = function (port) {
var fs = require("fs");
var path = require("path");
var express = require('express');
var vhost = require('vhost');
var https = require('https');
var http = require('http');
var bodyParser = require("body-parser");
var normalizedPath = require("path").join(__dirname, "../BlazeData/ssl/");
var options = {
key: fs.readFileSync(normalizedPath + 'spring14.key'),
cert: fs.readFileSync(normalizedPath + 'spring14.cert'),
};
var app = express();
app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json());
var normalizedPath = path.join(__dirname, "../WebServices");
fs.readdirSync(normalizedPath).forEach(function(file) {
if (file.indexOf('.js') != -1) {
var url = file.substring(0, file.length - 3);
app.use(vhost(url, require(normalizedPath+"/"+file).app));
console.log( 'Registered Service -> %s:%d', url, port );
}
});
if (port == 80) {
var server = http.createServer(app).listen(port, function(){
console.log("Create HTTP WebServices");
console.log( 'Express server listening on port %d in %s mode', port, app.settings.env );
});
}
if (port == 443) {
var server = https.createServer(options, app).listen(port, function(){
console.log("Create HTTPS WebServices");
console.log( 'Express server listening on port %d in %s mode', port, app.settings.env );
});
}
}
I have another JS file that is used to run the script above, I use
var https1 = require('./clientAuthServer') to initiate the code from above where clientAuthServer.js is the filename of the main code, however it just skips everything from that file.
How would I call module.exports = function (port) from a separate file and give a value to the parameter "port" which the function is using?
When you require your module it returns a function (the function exported by the module). The function is being assigned to the variable https1, so you simply need to call that function because right now it's just being stored.
The simplest way would be for your require statement to look something like this:
const https1 = require("./clientAuthServer")(parameter);
Where parameter is just whatever value you want to pass to the function.
const express = require('express');
const app = express();
const port = 3000;
const bodyPar=require('body-parser');
const session = require('express-session');
const path=require('path');
var user=["Jared","Bill","Jason","Jeremy"];
app.use(express.static('proiect'));
app.use(bodyPar.urlencoded({extended : true}));
app.use(bodyPar.json());
app.use(session({secret:'secret',saveUninitialized:true,resave:true}));
var sess;
var s;
app.post('/login',function(req,res){
var i=0;
sess=req.session;
var username=req.body.username;
var pass=req.body.password;
var but=req.body.value;
s=0;
sess.email=username;
for(i=0;i<3;i++)
{
if(username==user[i])
{
s=s+1;
i=5;
}
}
if(pass="123")
s=s+1;
if(s==2)
res.redirect('homepage.html');
else
res.redirect('login-error.html');
res.end();
});
app.get('/homepage.html',function(req,res){
console.log('aaa');
});
app.get('bios.html',function(req,res){
console.log('aaa');
});
app.post('/guest',function(req,res){
sess=req.session;
sess.username="Guest";
s=2;
res.redirect('homepage.html');
});
app.get('/logout',function(req,res){
req.session.destroy(function(){
res.redirect('login.html');
s=0;
});
});
app.listen(port, () => console.log(`listening on port ${port}!`));
The server doesnt handle the app.get('homepage.html') or 'bios.html' it just displays the html file in the browser.(should hang and display smth on console).
Am i supposed to serve/render those files instead of directly accessing them in the browser?
Both of those files are in the /proiect/ folder i've included on the server.
Express finds the static HTML file and then returns that to the user. Therefore it skips the route handler you wrote.
If you are trying to perform some server-side logic and returning an HTML page, rather return the page inside your route handler to avoid such side effects. In this case, create your HTML file in a templates folder or something. Then you can put all your static resources in your static folder. So your structure would look something like this:
+ project_folder
+ static
+ css
- style.css
+ js
- app.js
+ templates
- bios.html
- homepage.html
- login.html
- login-error.html
- app.js
Then your app.js would look something like this:
const express = require('express');
const app = express();
const port = 3000;
const bodyPar=require('body-parser');
const session = require('express-session');
const path=require('path');
var user=["Jared","Bill","Jason","Jeremy"];
app.use(express.static('static'));
app.use(bodyPar.urlencoded({extended : true}));
app.use(bodyPar.json());
app.use(session({secret:'secret',saveUninitialized:true,resave:true}));
var sess;
var s;
app.get('/login', function(req, res) {
res.sendFile(path.join(__dirname, '/templates/login.html'));
});
app.post('/login',function(req,res){
var i=0;
sess=req.session;
var username=req.body.username;
var pass=req.body.password;
var but=req.body.value;
s=0;
sess.email=username;
for(i=0;i<3;i++)
{
if(username==user[i])
{
s=s+1;
i=5;
}
}
if(pass="123")
s=s+1;
if(s==2)
res.redirect('homepage');
else
res.redirect('login-error');
res.end();
});
app.get('/homepage',function(req,res){
res.sendFile(path.join(__dirname, '/templates/homepage.html'));
});
app.get('bios',function(req,res){
res.sendFile(path.join(__dirname, '/templates/bios.html'));
});
app.get('login-error', function(req, res) {
res.sendFile(path.join(__dirname, '/templates/login-error.html'));
});
app.post('/guest',function(req,res){
sess=req.session;
sess.username="Guest";
s=2;
res.redirect('homepage');
});
app.get('/logout',function(req,res){
req.session.destroy(function(){
res.redirect('login');
s=0;
});
});
app.listen(port, () => console.log(`listening on port ${port}!`));
So i have found an api for node https://github.com/schme16/node-mangafox
But i have no idea on how to use it
Lets say that i want to use this
mangaFox.getManga = function(callback){
$.get('http://mangafox.me/manga/',function(data){
var list = {};
data.find('.manga_list li a').each(function(index, d){
var b = $(d);
list[mangaFox.fixTitle(b.text())] = {id:b.attr('rel'), title:b.text()};
});
(callback||function(){})(list);
}, true);
}
What should i do to show the list in the '/' route
This i what i have so far
var express = require('express'),
path = require('path'),
mangaFox = require('node-mangafox');
var app = express();
app.get('/', function(req, res) {
});
app.listen(1337);
console.log('oke');
If some cloud help me understand how this works
app.get('/', function(req, res) {
function renderList(data) {
return Object.keys(data);
res.send(JSON.stringify(list));
}
var list = mangaFox.getManga(renderList);
});
This is the simplest thing I can come up with. You just get the object returned by the module, list its keys, and send back that stringified as your response. Try it out. You'll probably want to replace the renderList with some HTML templating.
I have put the server setting script into a separate js file called server.js. My problem is that I don't know how to get the value of cookie_key from the express middleware function and pass it back to the index.js file.
server.js:
var express = require('express'),
app = express(),
http = require('http').createServer(app),
cookie = cookieParser = require('cookie-parser'),
url = require('url');
module.exports = {
use_app : function(){
app.use(function (req, res, next) {
var cacheTime = 86400000*7; // 7 days
if (!res.getHeader('Cache-Control'))
res.setHeader('Cache-Control', 'public, max-age=' + (cacheTime / 1000));
next();
});
},
get_app : function(callback){
app.use(cookieParser());
app.get('/id/:tagId', function(req, res){ // parse the url parameter to get the file name
function getkey(err,data){ // get users' session cookie
var cookie_key;
if(err)
{
callback(err);
}
cookie_key = req.cookies["session"];
callback(cookie_key);
}
var filename = req.param("tagId");
res.sendFile(filename+'.html');
});
}
}
index.js:
var server = require('./server'),
server.use_app();
server.get_app(); // how to get the cookie_key when calling this function?
console.log(show_cookie_key_from the module);
if(cookie_key !== undefined)
{
// do something
}
I tried to write a callback function to fetch the cookie key but I don't think it's working.
Update from A.B's answer:
var server = require('./server');
server.use_app();
server.get_app(function(cookie){
if(cookie !== undefined)
{
// do something
}
});
But I still think there is something strange about this setup, what exactly are you trying to accomplish with splitting the app up like this?
Since you are using callback function and that is being poplulated with cookie value , you can get this like following:
var server = require('./server');
server.use_app();
server.get_app(function(cookie){
cookie_key= cookie
if(cookie_key !== undefined)
{
// do something
}
});
If you had a server js like so:
var app = require('express'),
http = require('http'),
news = require('./server/api/news'),
db = require('mongoose');
/* app config..... */
app.get('/api/news', news.list);
var server = http.createServer(app);
server.listen(app.get('port'), function () {
console.log("Server running");
});
And I wanted to create an API to handle adding news items to the database:
var db = require('mongoose');
/*** Public Interfaces ***/
function list(req, res) {
var offset = ~~req.query.offset || 0,
limit = ~~req.query.limit || 25;
db.News.find(function (err, newsItems) {
res.json(newsItems.slice(offset*limit, offset*limit + limit));
});
}
exports.list = list;
This API would exist in its own file, how do I use the instance of the db created in the server.js inside the new module.
Or do you create and open a new connection each time you query the database?
Thanks
I would probably do it more like this
the server :
var express = require('express'),
app = express(),
http = require('http'),
db = require('mongoose'),
news = require('./server/api/news')(db); // you can pass anything as args
app.get('/api/news', news.list);
/* add routes here, or use a file for the routes */
// app.get('/api/morenews', news.more_news); .... etc
http.createServer(app).listen(8000);
and in the ../news/index.js file or whatever you're using, I'd use a literal, but you can always use exports to pass back each method as well
module.exports = function(db) {
/* now db is always accessible within this scope */
return {
list : function (req, res) {
var offset = ~~req.query.offset || 0,
limit = ~~req.query.limit || 25;
db.News.find(function (err, newsItems) {
res.json(newsItems.slice(offset*limit, offset*limit + limit));
});
}, // now you can easily add more properties
more_news : function(req, res) {
res.end('Hello kitty');
}
}
}