Since hashing is so computationally expensive, we should use async methods with callback functions to not block connections while they are taking place. bcrypt methods are async by default, and we can provide a callback function to continue after completion. Link to Challenge : https://www.freecodecamp.org/learn/information-security/information-security-with-helmetjs/hash-and-compare-passwords-asynchronously Written Guide: https://www.notion.so/ganeshh123/Hash-and-Compare-Passwords-Asynchronously-2389ec5d63bb47a5af1f277232ffd4fc Full Playlist for this course : https://www.youtube.com/playlist?list=PLhGp6N0DI_1TeEsQOdf1JmV8PnkQfEpQ4 All Writen Guides for this course : https://www.notion.so/ganeshh123/8ba82d9d1ff84c4583d6e9418ebe426b All My Tutorials can be found at : https://www.notion.so/Tutorials-Ganesh-H-293ea420d34a464f9a1907e0405b5f26 00:00 - Introduction 00:16 - Why we should hash asynchronously 00:37 - Hashing Asynchronously - bcrypt.hash() Generates a hash for the given input with the number of rounds, or salt specified. Runs asynchronously, and the callback function provided is executed after with the result. https://www.npmjs.com/package/bcrypt#to-hash-a-password 03:10 - Check a password Asynchronously - bcrypt.compare() Checks that the given hash (second argument) is valid for the given input (first argument). The number of salt rounds can be obtained from the hash. Runs asynchronously, and the callback function provided is executed after with the result. https://www.npmjs.com/package/bcrypt#to-check-a-password 05:35 - Challenge Solution -————————————————————————————————————- HelmetJS is a type of middleware for Express-based applications that automatically sets HTTP headers to prevent sensitive information from unintentionally being passed between the server and client. While HelmetJS does not account for all situations, it does include support for common ones like Content Security Policy, XSS Filtering, and HTTP Strict Transport Security, among others. HelmetJS can be installed on an Express project from npm, after which each layer of protection can be configured to best fit the project. freeCodeCamp (also referred to as “Free Code Camp”) is a non-profit organization that consists of an interactive learning web platform, an online community forum, chat rooms, online publications and local organizations that intend to make learning web development accessible to anyone. Beginning with tutorials that introduce students to HTML, CSS and JavaScript, students progress to project assignments that they complete either alone or in pairs. Upon completion of all project tasks, students are partnered with other nonprofits to build web applications, giving the students pr ... https://www.youtube.com/watch?v=vNfXPf-Ey8U

We can add click and document loaded event listeners to only run code when certain conditions have been met. We specify the event as the first argument, and a callback function to run as the second argument. Link to Challenge : https://www.freecodecamp.org/learn/data-visualization/json-apis-and-ajax/handle-click-events-with-javascript-using-the-onclick-property Full Playlist for this course : https://www.youtube.com/playlist?list=PLhGp6N0DI_1RxEqV5H-ScZE4DWEIZUh5f All Writen Guides for this course : https://www.notion.so/ganeshh123/11cab36e8f814f34afcc0aaa2c91a644 All My Tutorials can be found at : https://www.notion.so/Tutorials-Ganesh-H-293ea420d34a464f9a1907e0405b5f26 Concepts: addEventListener() The EventTarget method addEventListener() sets up a function that will be called whenever the specified event is delivered to the target. Common targets are Element, Document, and Window, but the target may be any object that supports events (such as XMLHttpRequest). addEventListener() works by adding a function or an object that implements EventListener to the list of event listeners for the specified event type on the EventTarget on which it's called. https://developer.mozilla.org/en-US/docs/Web/API/EventTarget/addEventListener DOMContentLoaded The DOMContentLoaded event fires when the initial HTML document has been completely loaded and parsed, without waiting for stylesheets, images, and subframes to finish loading. https://developer.mozilla.org/en-US/docs/Web/API/Window/DOMContentLoaded_event onclick The onclick property of the GlobalEventHandlers mixin is the EventHandler for processing click events on a given element.The click event is raised when the user clicks on an element. It fires after the mousedown and mouseup events, in that order. https://developer.mozilla.org/en-US/docs/Web/API/GlobalEventHandlers/onclick -————————————————————————————————————- JSON (JavaScript Object Notation) is an open standard file format, and data interchange format, that uses human-readable text to store and transmit data objects consisting of attribute–value pairs and array data types. Ajax is a set of web development techniques using many web technologies on the client side to create asynchronous web applications. With Ajax, web applications can send and retrieve data from a server asynchronously without interfering with the display and behavior of the existing page. freeCodeCamp (also referred to as “Free Code Camp”) is a non-profit organization that consists of an interactive learning web platform, an online community forum, chat rooms, online publications and local organizations that intend to make learning web development accessible to anyone. Beginning with tutorials that in ... https://www.youtube.com/watch?v=EvQXlUTsfPw

Serializaton and Deserialization allow us to reduce our User objects into a small piece of information which we can efficiently store into a cookie. Link to Challenge : https://www.freecodecamp.org/learn/quality-assurance/advanced-node-and-express/serialization-of-a-user-object Written Guide: https://www.notion.so/ganeshh123/Serialization-of-a-User-Object-945e3c57bc144e07a96fca87f6230ce1 Full Playlist for this course : https://www.youtube.com/playlist?list=PLhGp6N0DI_1RL9djhgSH65pZhJ6xSyKX8 All Writen Guides for this course : https://www.notion.so/ganeshh123/ccf6039186334f83a54c1c9216f30e3c All My Tutorials can be found at : https://www.notion.so/Tutorials-Ganesh-H-293ea420d34a464f9a1907e0405b5f26 00:00 - Introduction 00:30 - MongoDB Installation 01:10 - Serialize Function - passport.serializeUser() Passport will call this to serialize the user to the session whenever you login a user with req.login(), or whenever a user is authenticated via passport.authenticate(). The function you pass in should call done(null, serializedUser). What this is going to do is set req.session.passport.user = serializedUser. https://github.com/jwalton/passport-api-docs#passportserializeuserfnuser-done--fnreq-user-done 04:06 - Deserialize Function - passport.deserializeUser() Passport will call this to deserialize the user from the session. Should call done(null, user). The serializedUser is req.session.passport.user. https://github.com/jwalton/passport-api-docs#passportdeserializeuserfnserializeduser-done--fnreq-serializeduser-done 05:05 - Getting the User Document from the database - db.collection.findOne() Returns one document that satisfies the specified query criteria on the collection or view. If multiple documents satisfy the query, this method returns the first document according to the natural order which reflects the order of documents on the disk. https://docs.mongodb.com/manual/reference/method/db.collection.findOne/ 09:02 - Challenge Solution -————————————————————————————————————- Node.js is an open-source, cross-platform, JavaScript runtime environment that executes JavaScript code outside a web browser. Node.js lets developers use JavaScript to write command line tools and for server-side scripting—running scripts server-side to produce dynamic web page content before the page is sent to the user's web browser. Express.js, or simply Express, is a web application framework for Node.js. It is designed for building web applications and APIs. It has been called the de facto standard server framework for Node.js. Express runs between the server created by Node.js and the frontend pages of a web application. Express also handles an application's routing. freeCodeCamp (also referred t ... https://www.youtube.com/watch?v=gYqR-pf1EGQ

If we are just looking for one result, we can call the findOne() method on a model. Once again we give an object with our desired properties, and this time an object is returned. We also look at how we can look for items inside an array in the document, using the $all operator. Link to challenge : https://www.freecodecamp.org/learn/apis-and-microservices/mongodb-and-mongoose/use-model-findone-to-return-a-single-matching-document-from-your-database Written Guide : https://www.notion.so/ganeshh123/Use-model-findOne-to-Return-a-Single-Matching-Document-from-Your-Database-7814ba2bbc4246f48f20e5389371bfe0 Full Playlist for this course : https://www.youtube.com/playlist?list=PLhGp6N0DI_1QJMb63oecYZ3lLjrF4PnIs All Writen Guides for this course : https://www.notion.so/ganeshh123/6f987e7260914612b06adf840dbb00c3 All My Tutorials can be found at : https://www.notion.so/Tutorials-Ganesh-H-293ea420d34a464f9a1907e0405b5f26 Concepts: model.findOne() Behaves like .find(), but it returns only one document (not an array), even if there are multiple items. It is especially useful when searching by properties that you have declared as unique. https://mongoosejs.com/docs/api.html#model_Model.find $all The $all operator selects the documents where the value of a field is an array that contains all the specified elements. https://docs.mongodb.com/manual/reference/operator/query/all/Model Models are fancy constructors compiled from Schema definitions. An instance of a model is called a document. Models are responsible for creating and reading documents from the underlying MongoDB database. https://mongoosejs.com/docs/models.html mongoose.model() When you call mongoose.model() on a schema, Mongoose compiles a model for you. The first argument is the singular name of the collection your model is for. Mongoose automatically looks for the plural, lowercased version of your model name. https://mongoosejs.com/docs/models.html#compiling -————————————————————————————————————- MongoDB is a cross-platform document-oriented database program. Classified as a NoSQL database program, MongoDB uses JSON-like documents with optional schemas. MongoDB is developed by MongoDB Inc. and licensed under the Server Side Public License (SSPL). Mongoose is an Object Data Modeling (ODM) library for MongoDB and Node.js. It manages relationships between data, provides schema validation, and is used to translate between objects in code and the representation of those objects in MongoDB. freeCodeCamp (also referred to as “Free Code Camp”) is a non-profit organization that consists of an interactive learning web platform, an online community forum, chat rooms, online publications and local organizations that intend to ma ... https://www.youtube.com/watch?v=OJ0YqgipiG0