While trying to serve a page from node.js app I hit with this question. how multiple files are serving from a server with a simple request from user?
For eg:
A user enters www.google.co.in in address bar
browser make a request to that url and it should end there with a response. But whats happening is, few more requests are sending from that page to server like a chain.
What I am thinking now is, how my web browser(chrome) is sending those extra requests... Or who is prompting chrome to do it? and ofcourse, how can I do the same for my node.js app.
Once chrome gets the html back from the website, it will try to get all resources (images, javascript files, stylesheets) mentioned on the page, as well as favicon.ico That's what I think you are seeing
You can have as many requests as you want, from the client side (browser), using ajax. Here's a basic example using jQuery.get, an abstraction of an ajax call:
$.get(
"http://site.com",
function(data) { alert(data); }
);
Related
I am implementing google reCaptcha. In the Google documentation, they say the way to do it. The documentation suggests server side validation of captcha. I wanted to know why we need to verify it in the server side as it is already verified in the UI side from the google server. Is it a suggested to implement captcha in the UI side alone with no validation in the server? What are the problems(if any) if done in UI alone.
a example would be: you're creating a register form and want to prevent bots to create a account on your site, you need to verify it serverside, because in the background you're sending a request which will look something like this:
POST /register 1.1 HTTP
Host: www.example.com
{"username":"example","email:"hey#gmail.de","captcha-token":"123984f729340fmu2q34f9"}
and if you dont send the captcha-token with the request or the server doesnt validate it, this bot could just spam this request without loading the frontend page. Please mind in head, that bots dont visit your "UI" (frontend page). Just verify everything serverside like text length, bad characters, rate limits...
can any explain me about how the server responds if we click the button in browser using PHP script then which situation we use JAVASCRIPT and which situation we have to use PHP .
If you're asking about how it works, I'll suggest to google about HTTP protocol, POST and GET methods.
Usually, you use JavaScript to send request to a server when you want it to be AJAX, ie when you want to send request to server and receive response without reloading page. And you use PHP when you have form in your HTML (like login or registration form), and you send it to server in one request to go to another page
I have a single page app written in node.js which has a fair amount of javascript and css.
now is it possible to load the offline version of webpage as soon as the url is entered and at the same time send the request to server and wait for response while the offline version is showing a nice splash screen?
in other words, instead of waiting for the response from server and then render the application, I prefer that browser would render the app while the request is being sent.
this way the page is loaded instantly(with the splash page) and the time that requests are being sent and responses are being returned, the javascript and css is being loaded which saves some time.
is this possible with modern technologies? and is it even a good idea?
I currently use res.error('message'); to show a message on the page that I load using res.redirect(url); in my Express/Node.js app.
Is there another way of showing a message, if I don't want it to be error message, but something else?
Thanks!
res.redirect(url) will actually issue an HTTP 302 redirect which will cause your user's browser to make a brand new request for whatever page is specified by the value in the url variable.
If you want to show the user a message after the redirect, you would need to store that message somewhere that will persist between requests and then read it on the subsequent page load. This is often accomplished by storing the message in a cookie or in server-side session state and is often referred to as flash storage.
The express-flash middleware can help you with this, although I'm not 100% certain of its compatibility with Express 4.
You also might find this SO question helpful.
You could use one of the other res method to send the message:
send('message') or end('message') seems being the most appropriated.
You could otherwise display some page with .render (view, templateParam).
More details here, on express request documentation
Use flash. They provide templates for error, success and informational messages. Very useful if your users are coming in with web browsers.
Ok, I am new to web dev and here's a stupid question. I have been through a few tutorials for node, express and backbone individually, but I can't seem to wrap my head around how they are integrated. Particularly, consider this use case:
Person X opens the browser, types in a URL and hits enter->Express responds to the request and sends some data back to the browser.
My question is, where does backbone come into the picture here ? I know it's a mvc framework to organize your JS code. But, I can't find a place in this use-case where the server/browser interacts with backbone. Only thing I can think of is that the backbone saving the route and serving the page the next time. But what about the first time ? It would be best if someone could explain to me how the request gets routed from client browser to express/backbone to browser again.
Also, am I correct in assuming response.send() or response.json() will send the result to backbone when model.fetch() is called ? I mean, is there no additional code required ? Being new to web dev, I'm quite not used to the idea of the framework 'taking care' of everything once you send the response back.
EDIT : Here's what I have understood so far. Feel free to correct me if I am wrong. When I access websites like gmail, the server first sends a big html file including backbone.js code in it. The backbone.js code listens for events like clicking on links in the html file and handles them if the links are defined in it routes(routes are always relative to current route, accessing a completely different route sends request to the server). So, if I click compose, my url remains the same because backbone handles the request. However, if I click Maps/News services in the bar above, the server handles the request.
There is no special integration between backbone and node.js.
If you use the standard backbone sync method then all you need to do is:
Use the static middleware in express to serve up your static html/js/... files.
Define RESTfule routes in express that conform to what backbone is expecting.
Backbone does indeed make an http call when you do model.fetch. You could look in Chome network tab to see where it's sending the request to and then implement that route in express.