Research-topics

Validation:

The Validation data is to make sure that your application is stable and secure. hapi allows this functionality by using the module joi.

Type of validation:

• Input validation : validate if query parameters are satisfied the condition, as in example below:

server.route({
 method: 'GET',
 path: '/{name}',
 handler: function (request, reply) {
     reply('Hello ' + request.params.name + '!');
 },
 config: {
     validate: {
         params: {
             name: Joi.string().min(3).max(10)
         }
     }
 }
});

• Headers validation
• Path parameters validation
• Query parameters validation
• Payload data validation, as example below:

server.route({
  method : 'POST',
  path : '/form',
  handler : function(req, reply ){
    var email = req.payload.email;
    reply('My eamil is : '+ email);

  },
  config :{
    validate : {
      payload :{
        email : Joi.string().email().required(),
        password : Joi.number().integer().required()

      }
    }
  }
});

Authentication:

Authentication is any process by which a system verifies the identity of a User who wishes to access it.

Password encryption is away to encrypt given password into unreadable characters.

To implement it inside hapi : - install bcrypt and hapi-auth-basic module ```js npm install bcrypt --save npm install hapi-auth-basic --save

 ```


-
 ```js
     const users = {
    john: {
        username: 'john',
        password: '$2a$10$iqJSHD.BGr0E2IxQwYgJmeP3NvhPrXAeLSaGCj6IR/XU5QtjVu5Tm',   // 'secret'
        name: 'John Doe',
        id: '2133d32a'
    }
    };
   const validate = function (request, username, password, callback) {
    const user = users[username];
    if (!user) {
        return callback(null, false);
    }

    Bcrypt.compare(password, user.password, (err, isValid) => {
        callback(err, isValid, { id: user.id, name: user.name });
    });
  };
 ```

Cookies and caching:

When writing a web application, using cookies is often a necessity. When using hapi, cookies are flexible, safe, and simple

server.state('data', {
 ttl: null,
 isSecure: true,
 isHttpOnly: true,
 encoding: 'base64json',
 clearInvalid: false, // remove invalid cookies
 strictHeader: true // don't allow violations of RFC 6265
});

and we can use cookies config in route like this:

{
 config: {
     state: {
         parse: true, // parse and store in request.state
         failAction: 'error' // may also be 'ignore' or 'log'
     }
 }
}

then we can set cookies by in response :

reply('Hello').state('data', { firstVisit: false });

caching

The Cache-Control header tells the browser and any intermediate cache if a resource is cacheable and for what duration

we can set caching in hapi:

server.route({
  path: '/hapi/{ttl?}',
  method: 'GET',
  handler: function (request, reply) {

      const response = reply({ be: 'hapi' });
      if (request.params.ttl) {
          response.ttl(request.params.ttl);
      }
  },
  config: {
      cache: {
          expiresIn: 30 * 1000,
          privacy: 'private'
      }
  }
});

Templating with helper functions: