luisenriquecorona · May 11, 2019 18:52
diff --git a/index.js b/index.js
 'use strict';

 var mysql       = require('mysql'),
    http        = require('http'),
    url         = require('url'),
    querystring = require('querystring');


 // Start a web server on port 8888. Requests go to function handleRequest

 http.createServer(handleRequest).listen(8888);

 // Function that handles http requests

 function handleRequest(request, response) {

 // Page HTML as  var pageContent one big string, with placeholder "DBCONTENT" for data from the database

 var pageContent= '<html>' +
 '<head>' +
 '<meta http-equiv="Content-Type" ' +
 'content="text/html; charset=UTF-8" />' +
 '</head>' +
 '<body>' +
 '<form action="/add" method="post">' +
 '<input type="text" name="content">' +
                  '<input type="submit" value="Add content" />' +
                  '</form>' +
                  '<div>' +
                  '<strong>Content in database:</strong>' +
                  '<pre>' +
                  'DBCONTENT' +
                  '</pre>' +
                  '</div>' +
                  '<form action="/" method="get">' +
                  '<input type="text" name="q">' +
                  '<input type="submit" value="Filter content" />' +
                  '</form>' +
                  '</body>' +
                  '</html>';

 // Parsing the requested URL path in order to distinguish between the / page and the /add route

 var pathname = url.parse(request.url).pathname;

 // User wants to add content to the database (POST request to /add)

 if (pathname == '/add') {
 var requestBody = '';
 var postParameters; request.on('data', function (data) {
    requestBody += data;
  });
 request.on('end', function() {
 postParameters = querystring.parse(requestBody);

 // The content to be added is in POST parameter "content" 

 addContentToDatabase(postParameters.content, function() {

 // Redirect back to homepage when the database has finished adding the new content to the database

 response.writeHead(302;{'Location': '/'});

 response.end();

 }); 
 });

 // User wants to read data from the database (GET request to /)

 }else{

 // The text to use for filtering is in GET parameter "q"

 var filter = querystring.parse(url.parse(request.url).query).q;

 getContentsFromDatabase(filter, function(contents) { 

 response.writeHead(200, {'Content-Type': 'text/html'});

 // Poor man's templating system: Replace "DBCONTENT" in page HTML with the actual content we received from the database 

 response.write(pageContent.replace('DBCONTENT', contents)); 

 response.end();

 }); 
 }
 }

 // Function that is called by the code that handles the / route and retrieves contents from the database, applying a LIKE filter if one was supplied

 function getContentsFromDatabase(filter, callback) { 

 var connection = mysql.createConnection({
    host: 'localhost',
    user: 'root',
    password: 'root',
    database: 'node'
 });
 var query;
 var resultsAsString = '';
 if (filter) {

 query = connection.query('SELECT id, content FROM test ' +
                         'WHERE content LIKE "' + filter + '%"');
 query = connection.query('SELECT id, content FROM test');

 } else {

 }

 query.on('error', function(err) { console.log('A database error occured:'); console.log(err);
 });

 // With every result, build the string that is later replaced into the HTML of the homepage

 query.on('result', function(result) {
  resultsAsString += 'id: ' + result.id;
  resultsAsString += ', content: ' + result.content;

 resultsAsString += '\n';
  });

 // When we have worked through all results, we call the callback with our completed string

 query.on('end', function(result) {
    connection.end();
    callback(resultsAsString);
  });
 }

 // Function that is called by the code that handles the /add route and inserts the supplied string as a new content entry

 function addContentToDatabase(content, callback) { var connection = mysql.createConnection({
    host: 'localhost',
    user: 'root',
    password: 'root',
    database: 'node',
  });
  connection.query('INSERT INTO test (content) ' +
                   'VALUES ("' + content + '")',
 function(err) { if (err) {
        console.log('Could not insert content "' + content +
                    '" into database.');
 }
      callback();
    });
	'use strict';

	var mysql = require('mysql'),
	http = require('http'),
	url = require('url'),
	querystring = require('querystring');


	// Start a web server on port 8888. Requests go to function handleRequest

	http.createServer(handleRequest).listen(8888);

	// Function that handles http requests

	function handleRequest(request, response) {

	// Page HTML as var pageContent one big string, with placeholder "DBCONTENT" for data from the database

	var pageContent= '<html>' +
	'<head>' +
	'<meta http-equiv="Content-Type" ' +
	'content="text/html; charset=UTF-8" />' +
	'</head>' +
	'<body>' +
	'<form action="/add" method="post">' +
	'<input type="text" name="content">' +
	'<input type="submit" value="Add content" />' +
	'</form>' +
	'<div>' +
	'<strong>Content in database:</strong>' +
	'<pre>' +
	'DBCONTENT' +
	'</pre>' +
	'</div>' +
	'<form action="/" method="get">' +
	'<input type="text" name="q">' +
	'<input type="submit" value="Filter content" />' +
	'</form>' +
	'</body>' +
	'</html>';

	// Parsing the requested URL path in order to distinguish between the / page and the /add route

	var pathname = url.parse(request.url).pathname;

	// User wants to add content to the database (POST request to /add)

	if (pathname == '/add') {
	var requestBody = '';
	var postParameters; request.on('data', function (data) {
	requestBody += data;
	});
	request.on('end', function() {
	postParameters = querystring.parse(requestBody);

	// The content to be added is in POST parameter "content"

	addContentToDatabase(postParameters.content, function() {

	// Redirect back to homepage when the database has finished adding the new content to the database

	response.writeHead(302;{'Location': '/'});

	response.end();

	});
	});

	// User wants to read data from the database (GET request to /)

	}else{

	// The text to use for filtering is in GET parameter "q"

	var filter = querystring.parse(url.parse(request.url).query).q;

	getContentsFromDatabase(filter, function(contents) {

	response.writeHead(200, {'Content-Type': 'text/html'});

	// Poor man's templating system: Replace "DBCONTENT" in page HTML with the actual content we received from the database

	response.write(pageContent.replace('DBCONTENT', contents));

	response.end();

	});
	}
	}

	// Function that is called by the code that handles the / route and retrieves contents from the database, applying a LIKE filter if one was supplied

	function getContentsFromDatabase(filter, callback) {

	var connection = mysql.createConnection({
	host: 'localhost',
	user: 'root',
	password: 'root',
	database: 'node'
	});
	var query;
	var resultsAsString = '';
	if (filter) {

	query = connection.query('SELECT id, content FROM test ' +
	'WHERE content LIKE "' + filter + '%"');
	query = connection.query('SELECT id, content FROM test');

	} else {

	}

	query.on('error', function(err) { console.log('A database error occured:'); console.log(err);
	});

	// With every result, build the string that is later replaced into the HTML of the homepage

	query.on('result', function(result) {
	resultsAsString += 'id: ' + result.id;
	resultsAsString += ', content: ' + result.content;

	resultsAsString += '\n';
	});

	// When we have worked through all results, we call the callback with our completed string

	query.on('end', function(result) {
	connection.end();
	callback(resultsAsString);
	});
	}

	// Function that is called by the code that handles the /add route and inserts the supplied string as a new content entry

	function addContentToDatabase(content, callback) { var connection = mysql.createConnection({
	host: 'localhost',
	user: 'root',
	password: 'root',
	database: 'node',
	});
	connection.query('INSERT INTO test (content) ' +
	'VALUES ("' + content + '")',
	function(err) { if (err) {
	console.log('Could not insert content "' + content +
	'" into database.');
	}
	callback();
	});