Difference between hosting a Web API and hosting a website - api

From what I've gathered, hosting a website on a server is allocating space for the files of your website whereas hosting an API is when the server continuously runs your API to receieve incoming web requests. Is it true that when hosting a website, the server is not running anything? Or is it also continuously running the website waiting for calls.

When you request a website, it makes a call through the network to a server machine that runs an application called a web server, for example Apache HTTP Server. Without that application, it would be unable to respond to your HTTP calls with web pages.
Web pages are just documents and resources, so they are not able to respond by themselves. An API, on the other hand, is usually a separate standalone application that can run on a different machine, and that is often called by web pages.
So the answer is no: the server has to run something even for a static website.

You need a server to "serve" your web-page. It does not matter if is a static page or a dynamic page (html or php). If you have a html page the server will read and sent it to the user(No processing done), if you have a dynamic page like php then the server will process the php code and generate a result usually an HTML page that its serve to the client.
If you have an API is the same approach as the dynamic page, you send parameters, server process them and then give you a result. In the case of an API it may require authentication and the result can be in HTML, XML, JSON for example.

Related

How does API work with application server?

I've read that application server can be accessed via API. But I don't get the mechanism of that process. Does it work like that?
So, as for me, firstly, client sends an HTTP request to a hardware server. Here we start to looking for some data. Then, we connect with application server via API. And then something that was found in hardware server changes with application server. And after all, client receives this changed file. Am I right?
And it looks like API always works only with application server. Is it true?

what is the difference between web service and http and api?

i am taking a course in web data so i understand that when we want to retrive a webpage on a browser we do a request response cycle using a communication protocol like http or https and a web service is a piece of software which i dont know where it is stored or how it is accessed so we can make two applications from different architectures communicate using a serialization language like XML or JSON i dont know what is the difference between a web service and http they are both a way to connect 2 different computers together and what confused me the more is api which according to the research i did is something used to access web services.
Let's begin with defining all the terms in your question since it's a bit all over the place.
HTTP (Hypertext-Transport Protocol): Allows you to transfer data over the web. Your browser will perform a request using HTTP to your web service.
Service: Any software that performs a specific task. We are interested in a web service, which is typically invoked via HTTP, however this can be anything else such as a Linux signal.
For now, let's assume it listens on HTTP.
API (Application Programming Interface): An interface by which all clients of your software have to abide by to use it. For example, in our web service, we can dictate an API so requests follow some convention.
Let's put it all together now.
You're making a website that wants to calculate the sum of two numbers. First, users will go to http://yoursite.com, and then the browser will always do an HTTP request to the domain yoursite.com on port 80. This will hit either your hosting site or some backend server.
Here you have the option if you're using something like GitHub pages to serve static content or you have some server (i.e., serverd) that will load a file and serve it.
So now the web-browser did an HTTP request and your webpage should load with an index.html. The user can now click on buttons, and everything looks good until they press Calculate -- what happens now?
We want to offload the computation to our backend. We perform an HTTP request to our backend server. We can define an API, that is in our case an endpoint, so that the HTTP request can hit it and it'll return the sum of the two numbers.
How do we return the result? We need to represent the data somehow, and this can be done through a body payload that is encoded as either JSON or XML. Again, this is a serialization format and can encode it in various different ways. JSON is nice because you can parse it easily with JavaScript on the client side.
Great -- so now we got an entire site and it works! Now we can do an HTTP request from our browser straight to the backend according to our setup endpoint and it should fulfill our request. Notice how now we're using the API from the backend server from within our site.
Other keywords you can may run into: CORS, AJAX, Apache Server; good luck!

Ajax call to the Application Server sitting behind firewall

We have 3 tiered architecture:
Web Server - public (web application deployed) App Server - private (webApi deployed) Db Server - private (sql server installed) And my co-worker said, we have this architecture like this, because its a standard architecture that follows everywhere.
We have been using Asp.net application, where we can make api call from Web Server to App Server without any problem.
But now we have been converting our application from Server side to Client side, i.e. we'll only have js, html & css pages in web application, but problem is, we cannot call api using ajax directly from js, because of the two reason.
our App server is on different domain. App server is behind firewall, means it can only be accessed if we are connected to VPN, or we make a proxy on Web Server, and go through that channel. i.e. js<->Web Server Proxy<->App Server<->Db Server. We want to bypass Web Server from the channel, like: js<->App Server<->Db Server without connecting to VPN, because we don't require user to connect to VPN to use our web application.
Please give your suggestions. Thanks..
You have to enable CORS or cross origin resource sharing. You can research more on that but just want to give idea.

Is it possible to create a website with WCF?

Is it possible to create a website (hosted locally on my machine is fine for now) using a WCF Service Application?
By "web site" I mean allow an HTTP call from a web browser to my service and have the service return an HTML page that the browser can then render/display.
I am doing something very similar using a WCF based REST service. I have a WCF service that is accessed only from a web browser to download images. If you browse to 'http://www.MyFooImageService.com/100', it will lookup from the database an image with ID 100 and serve it up to the user. I use it to serve images from WCF service for the purpose of sending (user defined) emails with embedded images.
I used this guide with great results: RESTFUL WCF Service Step-ByStep. Check it out and see if a REST based WCF service is what you are looking for.
No, it doesn't quite work like that. WCF applications are service applications. There is no GUI interface or web interface or any kind of interface at all.
What you do is you create a WCF service that does some sort of function. Lets say you create a method called StoreName that stores your name into a database. Keep it simple. WCF services can be hosted in a variety of ways, depending on how you plan to use it. But to keep it simple, lets say you host the application using IIS.
Now this WCF application has no interface for interacting with it. You need to create an ASP.NET application (or it can be PHP, or jQuery if you prefer). It might have a text box and a submit button. Once the submit button is pushed, the ASP.NET application (or jQuery or PHP) makes an ajax call to your WCF service, passing it in the name as a POST parameter. The WCF service then does the work of storing it in the database. Execution then returns back to your web application.
This is a general overview of how this works. I hope it helps!
A website involves:
1) A user requesting HTML from somewhere
You can proxy pass a simple HTTP Get request to a WCF service hosted in a console app (or hosted in IIS), and configure it to return an HTTP request of content type text/html. Then the user would see a website appear in the browser.
But WCF is not a good fit for this. Especially if it's a simple HTML page. Others have said ASP.NET is better for this. And that's true. But node.js or PHP or pretty much anything that isn't .NET is MUCH better for this.
2) A user uses the web page to interact with server processes
This involves a user clicking a button or moving a mouse, or anything, and then that results in the web page (actually a web app at this point) making AJAX requests to one, or several server(s).
WCF is quite a good fit for this.

Modifying html repsonse from a webserver before it reaches the browser using a webserver plugin?

The question is as simple as the title. I have a webapp (I have no clue as to what technology it was built on or what appserver it is running on). However, I do know that this webapp is being served by an Apache Server/ IIS Server / IBM Http Server. Now, I would like to have a plugin/ module / add-on at the web-server end, which would parse/truncate/cut/regex the http response (based on the requested url's pattern), and mask(encrypt/shuffle/substitute) a set of fields in this response based on different parameters(user's LDAP permissions in the intranet / user's geo-location if on the internet, etc) and send the altered response back to the user.
So, Is there an easy answer to creating such plugins/modules/add-ons? How feasible is this approach of creating extra software at the webserver, when you want to mask sensitive information in a webapp without modfying the web-app code? Are there any tools that help you do this for Apache?
And, finally, is this just a really crazy thing to try?!
Each webserver will have its own way of doing so.
There is no universal plugin architecture for webservers.
In IIS you would write an HTTP Handler or HTTP Module, or possibly an ISAPI Filter. You can also directly interact with the http response using the Response object exposed by the HttpContext.
With apache, there are different modules that can do what you want (mod_headers, for example).
I don't know anything about WebSphere, but I am certain it also has similar mechanisms.
What you are asking is required by most web applications, so would be either built in or very easy to do.
The easiest way is to add a plug-in using the web application container. For example, if it's Tomcat, you can add a filter or valve.
If you want to plug-in to the web server, you'd need to write a custom module using the API of whichever web server is being used.
If all else fails, you could always wrap the entire server in a reverse proxy. All requests would go through your proxy and that would give you the opportunity to modify the requests and the responses.