Create a code for form validation using java script in node js.

May 26, 2023
| No Comments

Here, we will write a program to validate a java form in node js. For that we need to create two files, one will be app.js which will contain our imported libraries and schemas and another will be index.js file where we will design our form to validate.

app.js

Example
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
const express=require('express');
const fastestValidator=require('fastest-validator');
var bodyParser=require('body-parser');
const expressSession=require('express-session');
const v = new fastestValidator();
const app=express();
 
app.use(bodyParser.urlencoded({extended:false}))
app.use(bodyParser.json())
app.use(expressSession({
    secret:"Itsasecretkey",
    saveUninitialized:false,
    resave:false
 }))
 
app.set("view engine","ejs")
app.get('/',(req,res)=>{
    res.render("index",{usernameerror:req.session.usernameerror,emailerror:req.session.emailerror,passworderror:req.session.passworderror,
    success:req.session.success});
    req.session.usernameerror=null;
    req.session.emailerror=null;
    req.session.passworderror=null;
    req.session.success=null;
})
 
const schema = {
    username : {
        type:"string",min:5,max:15
    },
    email:{
        type:"email"
    },
    password:{
        type:"string", min:4
    }
}
 
app.post('/',(req,res)=>{
    var username=req.body.username;
    var email=req.body.email;
    var password=req.body.password;
 
    const check = v.compile(schema);
    const result=check({
        username:username,
        email:email,
        password:password
    })
    if(result){
        req.session.success=true;
        res.redirect('/')
    }
    else{
        req.session.usernameerror=result[0].message;
        req.session.emailerror=result[1].message;
        req.session.passworderror=result[2].message;
        req.session.success=false;
        res.redirect('/')
    }
 
    console.log(username);
    console.log(email);
    console.log(password);
    console.log(result);
})
app.listen(4000,()=>{
    console.log("App is listening on port 4000")
})

index.js

Example
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Express Validation using javascript</title>
    <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.0.2/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-EVSTQN3/azprG1Anm3QDgpJLIm9Nao0Yz1ztcQTwFspd3yD65VohhpuuCOmLASjC" crossorigin="anonymous">
</head>
<body>
    <div class="container"><br>
        <h1 class="text-center">Form Validation using Express in Node js.</h1><br>
        <% if(success) { %>
            <div>
               <p class="alert alert-success"> Form Successfully Validated </p>
            </div>
        <% } %>
        <form action="/" method="post" autocomplete="off">
            <% if(usernameerror) { %>
                <p class="alert alert-danger"><%= usernameerror %></p>
                <% } %>
            <div class="form-group">
              <input type="text" placeholder="username" name="username" class="form-control">
            </div><br>
            <% if(emailerror) { %>
                <p class="alert alert-danger"><%= emailerror %></p>
                <% } %>
            <div class="form-group">
              <input type="text" name="email" id="" placeholder="Email" class="form-control">
            </div><br>
            <% if(passworderror) { %>
                <p class="alert alert-danger"><%= passworderror %></p>
                <% } %>
            <div class="form-group">
                <input type="password" name="password" id="" placeholder="Password" class="form-control">
            </div><br>
            <div class="form-group" class="form-control" >
                <button class="btn btn-danger btn-block">
                    Submit
                </button>
            </div>
        </form>
    </div>
     
</body>
 
<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.0.2/dist/js/bootstrap.bundle.min.js" integrity="sha384-MrcW6ZMFYlzcLA8Nl+NtUVF0sA7MsXsP1UyJoMp4YLEuNSfAP+JcXn/tWtIaxVXM" crossorigin="anonymous"></script>
 
</html>
Assignments, Practice Questions, Questions
| Tags: , , ,