streams

ip address and domain

in node we manually create server to request from browser actively for request and response to it to require a core http module use method call back function gonna run every time a request

---

creatimg a server

comes in in our server get access to two different object req and res req ->example www.anywebsite.com/about res->it will re direct me to about page we have to invoke the listen method we need to pass in an argument into this

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localhost and port number

port number we goin listen to two argument server.listen 3000 ,local host this is the default value to local host like domain name on the web spceific ip address called a loop back ip adress 127.0.0.1 request it and going back to your computer acting as a host for our website a port number is like a specif channel or port on your computer that server should communicate through

request object

lets investigate request object more closer

---

const server= http.createServer((req,res)=>{
    console.log(req);
});

in the terminal will load different things of object it contains headers ,response type,URL(the user has visited)

const server= http.createServer((req,res)=>{
    console.log(req.url,req.method);
});

/the root of the website ,the method is GET request

response object

we want to formulate some kind of response for the request of the user by the browser first thing first is to formulate the response headers give the browser "what kind of response is coming back to it " (text -html -json .... etc ) also headers can set cookies

---

const server= http.createServer((req,res)=>{
    console.log(req.url,req.method);
    res.setHeader('Content-Type','text/plain');
    res.write('hello');
    res.end();
});

---

const server= http.createServer((req,res)=>{
    console.log(req.url,req.method);
    res.setHeader('Content-Type','text/html');
    res.write(<p>'hello'</p>);
    res.end();
});

returning html pages

lets be more defined and instead of returing resonse with the tags or plain text ,return html page

const fs=require ('fs');
const server= http.createServer((req,res)=>{
    console.log(req.url,req.method);
    res.setHeader('Content-Type','text/html');
   fs.readFile('./index.html',(err,data)=>{
    if(err){
        console.log(err);
        res.end();
    }
    else{
        
        res.end(data);
    }
   })
});

basic routing

now we have a lot of route directory to handle it

const fs=require ('fs');
const server= http.createServer((req,res)=>{
    console.log(req.url,req.method);
    res.setHeader('Content-Type','text/html');
   let path='/file';
   switch(req.url){
    case'/':
       path+='index.html';
       break;
     case'/about':
       path+='about.html';
       break; 
    default:
       path+='404.html';
       break;     
   }

   fs.readFile('./index.html',(err,data)=>{
    if(err){
        console.log(err);
        res.end();
    }
    else{
        
        res.end(data);
    }
   })
});

status code

status code describe the type of response sent to the browser

200 = ok 301 = resource moved 404-not found 500-internal server error

lets try this

const fs=require ('fs');
const server= http.createServer((req,res)=>{
    console.log(req.url,req.method);
    res.setHeader('Content-Type','text/html');
   let path='/file';
   switch(req.url){
    case'/':
       path+='index.html';
       res.statusCode=200;
       break;
     case'/about':
       path+='about.html';
       res.statusCode=200;
       break; 
    default:
       path+='404.html';
       res.statusCode=404;
       break;     
   }

   fs.readFile('./index.html',(err,data)=>{
    if(err){
        console.log(err);
        res.end();
    }
    else{
        
        res.end(data);
    }
   })
});

try to redirect your response ;)