I'm working on a SPA website with node.js, jQuery, mongoose and MongoDB for a shopping website.
The ajax requests and responses work perfectly when starting from the index.html file. So for example begining on http://localhost:3000 and someone clicks on a link called 'products' I send an ajax request to the the server and the server sends the necessary product information back asynchronously which lead to http://localhost:3000/products. But the problem is that if someone types http://localhost:3000/products directly in the search bar it will show the json representation of the products.
This is my code:
script.js
function redirect (link) {
$.ajax({
type: 'GET',
url: 'http://localhost:3000/' + link,
contentType: 'application/json',
data: {
link
},
success: function (res) {
let container = $('#contentToSwap');
container.html('');
res.products.forEach(function (products_) {
...
});
}
});
}
app.js
var Product = require('./models/product');
var mongoose = require('mongoose');
var bodyParser = require('body-parser');
var path = require('path');
var express = require('express');
var app = express();
mongoose.connect('mongodb://localhost:27017/shopping');
var PORT = process.env.PORT || 3000;
app.use(express.static(path.join(__dirname, 'public')));
app.use(bodyParser.json());
app.get('*', function(req, res) {
Product.find(function(err, docs) {
let productChunks = [];
let chunksize = 4;
let display = [];
for (var i = 0; i < docs.length; i++) {
if (docs[i].productType == req.query.link) display.push(docs[i]);
}
for (var i = 0; i < display.length; i += chunksize) {
productChunks.push(display.slice(i, i + chunksize));
}
res.send({ products: productChunks });
});
});
app.listen(PORT, function () {
console.log('Listening on port ' + PORT);
});
So I need some sort of frontend routing if the user doesn't start at the index.html file. I know that I could write my own router to route the urls correctly and that I could route all requests back to the index.html like
app.get('*', function(req, res) {
res.sendFile(__dirname + '/public/index.html');
});
But then I cannot load all the necessary product information from the server when someone clicks a link. So I'm a little bit confused on hwo to tackle this issue. Any help is appreciated
This is usually achieved by separating api routes from normal ones by adding specific url prefixes such as /api for all routes that return json data. What you can do is to specify /api/whatever-you-want, make it the target for your ajax call and place it above app.get('*' ....
Since routes and middleware functions are resolved top to bottom, it will be matched by your ajax call only, leaving the /products unaffected.
answer to question -- Is it possible to redirect user from /api/products to /product if the request wasn't generated by ajax?
Yes, it is possible by adding request query parameter to ajax call which will not be present on normal call and then check those on the server side and decided what to do if it (that specific query parameter) is missing or not.
Let's assume some client side JS that generates ajax call.
fetch('/api/products?api=true')
.then((data) => data.json())
.then((json) => console.log(json));
Notice the request url - /api/products?api=true
Now assume a normal call from html file.
products
These two calls differ in that api query parameter (ajax call has it, the other one doesn't).
And for the server side part of the task -- request query parameters object can be accessed via query property on request object (req.query).
app.get('/api/products', (req, res) => {
if (!req.query.api) {
// if get request doesn't contain api param. then
// handle it accordingly, e.g. do redirect
return res.redirect('/products');
}
// request comming from ajax call, send JSON data back
res.json({ randomStuff: 'abcd' });
});
Related
Edit: Actually, my problem is "How to use "value" from selection.js in the server.js ? " I want to direct user to a searching page according to his/her choice .
i am new at web programming. I have server.js and a selection.js.
server.js is a node file, and my server is in it. selection.js is my item class changer. I am changing selected item's class with selection.js and i am trying to use this selected item from server.js. When i try below codes, i am taking this shit: Document is not defined on node.js
It is really painful. I am trying to solve it about hours. But, nothing!
Pls, help me :/
selection.js :
var iconContainer = document.getElementById('iconContainer');
var icon = iconContainer.getElementsByClassName("item");
for (var i = 0; i < icon.length; i++) {
icon[i].addEventListener("click", function() {
var current = document.getElementsByClassName("active");
current[0].className = current[0].className.replace(" active", "");
this.className += " active";
const btnSearch = document.querySelector("#btnSearch");
btnSearch.addEventListener("click", () => {
// get the active item's value
const value = document.querySelector(".item.active span").innerText;
console.log("value: ", value);
// do fetch
});
});
}
module.exports={searchPath: "/"+value};
server.js:
var fs = require('fs');
var express = require('express');
var app = express();
var path = require('path');
app.use('/public', express.static(path.join(__dirname, 'public')));
// '/' girdisi için index.html getirilecek.
app.get('/', function (req, res) {
fs.readFile('index.html', function(err, data) {
res.writeHead(200, {'Content-Type': 'text/html'});
res.write(data);
res.end();
});
});
//---------------------------------------------------
// Server kuruyoruz.
var server = app.listen(8081,"127.0.0.1", function () {
var host = server.address().address;
var port = server.address().port;
console.log('Server http://' + host + ':' + port+' adresinde çalışıyor...');
});
var search = require('./public/js/selection');
console.log(search.searchPath);
So, the code you label as selection.js needs to be in your web page, either directly embedded or linked from a <script> tag so it can run in the web page in the browser.
Then, that code can make an Ajax call using the XMLHttpRequest or fetch() interfaces in the browser to a route on your server and pass the desired value.
That route on your server (which you need to define and add code for) can then examine that value and decide what data to return the the Ajax call.
Your Javascript in the web page, then receives that returned data from the Ajax call and decides what to do with it such as insert new content in the page for the user to see, cause the browser to load a different page or refresh the current page or whatever else is appropriate.
I have been creating a website with Mean stack and I stuck at some point. I have a mongo db database and I am currently getting each file from database (to show them on Main page) with my Rest Api which is build with Express.
Server.js
var express = require('express');
var app = express();
var mongojs = require('mongojs');
var db = mongojs('mongodb://username...', ['myApp']);
var bodyParser = require('body-parser');
app.use(express.static(__dirname + '/public'));
app.use(bodyParser.json());
app.get('/myApp', function (req, res) {
db.myApp.find(function (err, docs) {
console.log(docs);
res.json(docs);
});
});
app.get('/myApp/:id', function (req, res) {
var id = req.params.id;
console.log(id);
db.myApp.findOne({_id: mongojs.ObjectId(id)}, function (err, doc) {
res.json(doc);
})
});
app.listen(3001);
console.log('Server running on port 3001');
There is 2 get method and I can understand that because they have different parameters. So when I call them from controllers, there is no problem because if I provide id, it will call the second get method. But for example I want to use something like this in my website;
app.get('/myApp', function (req, res) {
db.myApp.find({}).limit(2).skip(0, function(err, docs) {
console.log(docs);
res.json(docs);
});
});
This get method have no parameter like the first get method in server.js but they do different jobs. This is limiting my search with 2 file. How can I use different get methods like this in my Mean Stack application?
This is my code for calling get method from my main controller. How can I make sure to call specific get method? Thanks..
$http.get('/myApp').success(function(response) { .. });
What you want is not possible. Somehow you need to distinguish between your 2 intentions, either by giving the endpoints different names (like you already suggest in your comment) or by providing for example a query parameter so you could do a call like:
$http.get('/myApp?limit=2').success(function(response) { .. });
When limit is omitted, you could return all results.
Something like:
app.get('/myApp', function (req, res) {
var limit = req.query.limit;
if (limit === undefined) {
// Return everything
} else {
// make sure limit is some valid number
// ... and do a mongo query limited to this number
}
});
I really hope to find some answers here as i tried everything by now.
Background:
Overtime we deploy code to web server, we need to do a cache warm up, i.e. access the site and make sure it loads. First load is always the slowest since IIS require to do some manipulations with a new code and cache it.
Task:
Create a page which will a checkbox and a button. Once button is pressed, array of links sent to server. Server visits each link and provides a feedback on time it took to load each page to the user.
Solution:
I am using node JS & express JS on server side. So far i manage to POST array to the server with links, but since i have limited experience with node JS, i can not figure out server side code to work.
Here is a code i got so far (it is bits and pieces, but it gives an idea of my progress). Any help will be greatly appreciated!!!
var express = require("express");
var app = express();
var bodyParser = require('body-parser');
var parseUrlencoded = bodyParser.urlencoded({ extended: false});
var http = require("http");
function siteToPrime(url){
http.get(url, function (http_res) {
// initialize the container for our data
var data = "";
// this event fires many times, each time collecting another piece of the response
http_res.on("data", function (chunk) {
// append this chunk to our growing `data` var
data += chunk;
});
// this event fires *one* time, after all the `data` events/chunks have been gathered
http_res.on("end", function () {
// you can use res.send instead of console.log to output via express
console.log(data);
});
});
};
//Tells express where to look for static content
app.use(express.static('public'));
app.post('/', parseUrlencoded, function(request, response){
var newBlock = request.body;
console.log(Object.keys(newBlock).length);
var key = Object.keys(newBlock)[0];
console.log(newBlock[key]);
siteToPrime("www.google.com");
response.status(201);
});
app.listen(3000, function(){
console.log("Server listening on port 3000...");
});
Assuming that you have access to the array in the post route:
var express = require("express"),
request = require("request"),
app = express();
var start = new Date();
app.use(express.static('public'));
app.use(bodyParser.urlencoded({extended: false}));
function siteToPrime(req, res, urls) {
urls.forEach(function(url)) {
request(url, function(error, res, body) {
if (!error && res.statusCode == 200) {
console.log(url +' : ' + body);
console.log('Request took: ', new Date() - start, 'ms');
}
});
}
res.redirect('/');
};
app.post('/', function(req, res){
var urls = req.body.urls // Array os urls.
siteToPrime(req, res, urls);
});
app.listen(3000, function(){
console.log("Server listening on port 3000...");
});
Recently I started learning a little bit about Node.js and it's capabilities and tried to use it for some web services.
I wanted to create a web service which will serve as a proxy for web requests.
I wanted my service to work that way:
User will access my service -> http://myproxyservice.com/api/getuserinfo/tom
My service will perform request to -> http://targetsite.com/user?name=tom
Responded data would get reflected to the user.
To implement it I used the following code:
app.js:
var express = require('express');
var bodyParser = require('body-parser');
var app = express();
app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json());
var proxy = require('./proxy_query.js')
function makeProxyApiRequest(name) {
return proxy.getUserData(name, parseProxyApiRequest);
}
function parseProxyApiRequest(data) {
returned_data = JSON.parse(data);
if (returned_data.error) {
console.log('An eror has occoured. details: ' + JSON.stringify(returned_data));
returned_data = '';
}
return JSON.stringify(returned_data);
}
app.post('/api/getuserinfo/tom', function(request, response) {
makeProxyApiRequest('tom', response);
//response.end(result);
});
var port = 7331;
proxy_query.js:
var https = require('https');
var callback = undefined;
var options = {
host: 'targetsite.com',
port: 443,
method: 'GET',
};
function resultHandlerCallback(result) {
var buffer = '';
result.setEncoding('utf8');
result.on('data', function(chunk){
buffer += chunk;
});
result.on('end', function(){
if (callback) {
callback(buffer);
}
});
}
exports.getUserData = function(name, user_callback) {
callback = user_callback
options['path'] = user + '?name=' + name;
var request = https.get(options, resultHandlerCallback);
request.on('error', function(e){
console.log('error from proxy_query:getUserData: ' + e.message)
});
request.end();
}
app.listen(port);
I wish I didn't screwed this code because I replaced some stuff to fit my example.
Anyway, the problem is that I want to post the response to the user when the HTTP request is done and I cant find how to do so because I use express and express uses asynchronous calls and so do the http request.
I know that if I want to do so, I should pass the makeProxyApiRequest the response object so he would be able to pass it to the callback but it is not possible because of asyn problems.
any suggestions?
help will be appreciated.
As you're using your functions to process requests inside your route handling, it's better to write them as express middleware functions, taking the specific request/response pair, and making use of express's next cascade model:
function makeProxyApiRequest(req, res, next) {
var name = parseProxyApiRequest(req.name);
res.locals.userdata = proxy.getUserData(name);
next();
}
function parseProxyApiRequest(req, res, next) {
try {
// remember that JSON.parse will throw if it fails!
data = JSON.parse(res.locals.userdata);
if (data .error) {
next('An eror has occoured. details: ' + JSON.stringify(data));
}
res.locals.proxyData = data;
next();
}
catch (e) { next("could not parse user data JSON."); }
}
app.post('/api/getuserinfo/tom',
makeProxyApiRequest,
parseProxyApiRequest,
function(req, res) {
// res.write or res.json or res.render or
// something, with this specific request's
// data that we stored in res.locals.proxyData
}
);
Even better would be to move those middleware functions into their own file now, so you can simply do:
var middleware = require("./lib/proxy_middleware");
app.post('/api/getuserinfo/tom',
middleware.makeProxyApiRequest,
middleware.parseProxyApiRequest,
function(req, res) {
// res.write or res.json or res.render or
// something, with this specific request's
// data that we stored in res.locals.proxyData
}
);
And keep your app.js as small as possible. Note that the client's browser will simply wait for a response by express, which happens once res.write, res.json or res.render etc is used. Until then the connection is simply kept open between the browser and the server, so if your middleware calls take a long time, that's fine - the browser will happily wait a long time for a response to get sent back, and will be doing other things in the mean time.
Now, in order to get the name, we can use express's parameter construct:
app.param("name", function(req, res, next, value) {
req.params.name = value;
// do something if we need to here, like verify it's a legal name, etc.
// for instance:
var isvalidname = validator.checkValidName(name);
if(!isvalidname) { return next("Username not valid"); }
next();
});
...
app.post("/api/getuserinfo/:name", ..., ..., ...);
Using this system, the :name part of any route will be treated based on the name parameter we defined using app.param. Note that we don't need to define this more than once: we can do the following and it'll all just work:
app.post("/api/getuserinfo/:name", ..., ..., ...);
app.post("/register/:name", ..., ..., ... );
app.get("/api/account/:name", ..., ..., ... );
and for every route with :name, the code for the "name" parameter handler will kick in.
As for the proxy_query.js file, rewriting this to a proper module is probably safer than using individual exports:
// let's not do more work than we need: http://npmjs.org/package/request
// is way easier than rolling our own URL fetcher. In Node.js the idea is
// to write as little as possible, relying on npmjs.org to find you all
// the components that you need to glue together. If you're writing more
// than just the glue, you're *probably* doing more than you need to.
var request = require("request");
module.exports = {
getURL: function(name, url, callback) {
request.get(url, function(err, result) {
if(err) return callback(err);
// do whatever processing you need to do to result:
var processedResult = ....
callback(false, processedResult);
});
}
};
and then we can use that as proxy = require("./lib/proxy_query"); in the middleware we need to actually do the URL data fetching.
I am using Node.js and express to make a web chat application. I have a question about routing.
My route is:
app.get("/", function( req, res ) {
res.sendfile( __dirname + "/index.html" );
});
And as far as I know it means all clients should go to http://www.example.com/index.html page to access the chat. ( maybe, not sure )
Is it possible to have a pattern URL like this:
app.get("/*", function( req, res ) {
res.sendfile( __dirname + "/*" );
});
so that any user can access to chat on any URL
In short: Something like facebook chat. which is accessible in all pages.
thanks in advance
Is it possible to have a pattern URL like this:
Yeah, Express supports exactly the route you listed. The documentation refers to it as an "unnamed wild-card."
// GET /foo -> (200) "foo"
// GET /baz/qux -> (200) "baz/qux"
app.get('/*', function (req, res) {
res.send(req.params[0]);
});
Though, for your example, Express/Connect includes a static() middleware for serving files by combining the URL path to a base directory:
app.use(express.static(__dirname));
Something like facebook chat. which is accessible in all pages.
This wouldn't necessarily have much of a relation to routing. Your application may need a route to gather a list of contacts or other persisted data, but the actual "chat" will be managed separately.
In general, it would depend on including common content in each page -- perhaps via a "layout" or "inheritance" if you're using views/templates -- to display the form for inputting message and an area to display chat history. Also, a fair amount of the "work" for the chat will have to be done client-side.
A quick example would be to serve the same file for multiple URLs:
var app = require('express')();
var server = require('http').createServer(app);
var io = require('socket.io').listen(server);
app.get('/*', function (req, res) {
res.sendfile(__dirname + '/chat.html');
});
var chat = io
.of('/chat') // namespace
.on('connection', function (socket) {
socket.on('message', function (data) {
chat.emit('message', data);
});
});
server.listen(3000);
And, in that file:
<div id="chat-log"></div>
<form id="chat-send">
<input name="message">
<input type="submit" value="Send">
</form>
<script src="/socket.io/socket.io.js"></script>
<script>
var chatForm = document.getElementById('chat-send');
var chatLog = document.getElementById('chat-log');
var chatSocket = io.connect('/chat');
chatSocket.on('message', function (data) {
chatLog
.appendChild(document.createElement('div'))
.appendChild(document.createTextNode(data.text));
});
chatForm.onsubmit = function () {
chatSocket.emit('message', {
text: chatForm.message.value
});
chatForm.message.value = '';
chatForm.message.focus();
return false;
};
</script>
Then, from any address (GET /, GET /foo, GET /bar/baz/qux), you can access chat.
You're probably going to want to use a url param like this:
app.get("/:chatter",function(req,res){
console.log("the chatter is",req.param('chatter'));
res.sendfile( __dirname + "/index.html" );
...
});