We can retrieve the data that body-parser captured from the form during a POST request from the request's body field. This is done by setting up a POST route for the form, running the urlencoded function, followed by our own middleware function. Link to challenge : https://www.freecodecamp.org/learn/apis-and-microservices/basic-node-and-express/get-data-from-post-requests Written Guide : https://www.notion.so/ganeshh123/Get-Data-from-POST-Requests-becb31b940214d35ae096a2ffa94de33 Full Playlist for this course : https://www.youtube.com/playlist?list=PLhGp6N0DI_1SdIZ3uhbXnKAq2UcICSnWS All Writen Guides for this course : https://www.notion.so/ganeshh123/dab5e189407244c793c2f32d066eee9f All My Tutorials can be found at : https://www.notion.so/Tutorials-Ganesh-H-293ea420d34a464f9a1907e0405b5f26 Concepts: bodyParser.urlencoded() Returns middleware that only parses urlencoded bodies and only looks at requests where the Content-Type header matches the type option. This parser accepts only UTF-8 encoding of the body and supports automatic inflation of gzip and deflate encodings. A new body object containing the parsed data is populated on the request object after the middleware (i.e. req.body). This object will contain key-value pairs, where the value can be a string or array (when extended is false), or any type (when extended is true). https://github.com/expressjs/body-parser#bodyparserurlencodedoptions request.body Contains key-value pairs of data submitted in the request body. By default, it is undefined, and is populated when you use body-parsing middleware such as express.json() or express.urlencoded(). https://expressjs.com/en/api.html#req.body app.post() Routes HTTP POST requests to the specified path with the specified callback functions. https://expressjs.com/en/api.html#app.post.method Middleware Middleware functions are functions that have access to the request object (req), the response object (res), and the next middleware function in the application’s request-response cycle. The next middleware function is commonly denoted by a variable named next. http://expressjs.com/en/guide/using-middleware.html response.json() Sends a JSON response. This method sends a response (with the correct content-type) that is the parameter converted to a JSON string using JSON.stringify(). The parameter can be any JSON type, including object, array, string, Boolean, number, or null, and you can also use it to convert other values to JSON. https://expressjs.com/en/api.html#res.json -————————————————————————————————————- 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 t ... https://www.youtube.com/watch?v=9zqOoBAEuEg

This is a guided walkthrough for the 'Visualize Data with a Scatterplot Graph' challenge on freeCodeCamp. We import some data about doping in bicycle racing, and use d3.js to produce a scatterplot diagram with it. Written Notes and Source Code : https://www.notion.so/ganeshh123/Visualize-Data-with-a-Scatterplot-Graph-f3b277dc35294accb4d42a0358b92009 Timestamps: 0:00 - Project Setup 05:10 - Creating Variables and Functions 08:33 - Fetching JSON Data 12:23 - User Story #1: I can see a title element that has a corresponding id="title" 13:54 - User Story #2: I can see an x-axis that has a corresponding id="x-axis" 18:12 - User Story #3: I can see a y-axis that has a corresponding id="y-axis" 22:47 - User Story #4: I can see dots, that each have a class of dot, which represent the data being plotted 25:00 - User Story #5: Each dot should have the properties data-xvalue and data-yvalue containing their corresponding x and y values 26:38 - User Story #6: The data-xvalue and data-yvalue of each dot should be within the range of the actual data and in the correct data format. For data-xvalue, integers (full years) or Date objects are acceptable for test evaluation. For data-yvalue (minutes), use Date objects 29:10 - User Story #7: The data-xvalue and its corresponding dot should align with the corresponding point/value on the x-axis 33:46 - User Story #8: The data-yvalue and its corresponding dot should align with the corresponding point/value on the y-axis 39:50 - User Story #9: I can see multiple tick labels on the y-axis with %M:%S time format 40:26 - User Story #10: I can see multiple tick labels on the x-axis that show the year 41:07 - User Story #11: I can see that the range of the x-axis labels are within the range of the actual x-axis data 42:40 - User Story #12: I can see that the range of the y-axis labels are within the range of the actual y-axis data 43:37 - Changing the dot colors 46:17 - User Story #13: I can see a legend containing descriptive text that has id="legend" 48:14 - User Story #14: I can mouse over an area and see a tooltip with a corresponding id="tooltip" which displays more information about the area 54:50 - User Story #15: My tooltip should have a data-year property that corresponds to the data-xvalue of the active area 54:50 - User Story #15: My tooltip should have a data-year property that corresponds to the data-xvalue of the active area 56:00 - Final Touches and Styling -————————————————————————————————————- D3.js (also known as D3, short for Data-Driven Documents) is a JavaScript library for producing dynamic, interactive data visualizations in web browsers. It makes use of Scalable Vector Graphics (SVG), HTML5, and Cascading Style Sheets (CSS) standar ... https://www.youtube.com/watch?v=OvtT4X2L9Fo

IMPORTANT: You must use Helmet version 2.3.0 to pass this test! Browsers use MIME Type Sniffing to try and parse a file by reading it's contents and making a guess of the file type. This can be exploited to run malicious scripts, and we can set a header using helmet's noSniff() middleware to disable this. Link to Challenge : https://www.freecodecamp.org/learn/information-security/information-security-with-helmetjs/avoid-inferring-the-response-mime-type-with-helmet-nosniff Written Guide: https://www.notion.so/ganeshh123/Avoid-Inferring-the-Response-MIME-Type-with-helmet-noSniff-e4c9340b0f5542b18ffe88e44f190d6a 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 00:06 - What is Mime Type Sniffing? Content sniffing, also known as media type sniffing or MIME sniffing, is the practice of inspecting the content of a byte stream to attempt to deduce the file format of the data within it. https://en.wikipedia.org/wiki/Content_sniffing 01:00 - Danger with MIME Type Sniffing https://youtu.be/eq6R6dxRuiU 01:54 - X-Content-Type-Options Header The X-Content-Type-Options response HTTP header is a marker used by the server to indicate that the MIME types advertised in the Content-Type headers should not be changed and be followed. This is a way to opt out of MIME type sniffing, or, in other words, to say that the MIME types are deliberately configured. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Content-Type-Options 02:30 - Use Helmet version 2.3.0 02:54 - Setting the Header - helmet.noSniff() helmet.noSniff sets the X-Content-Type-Options header to nosniff. This mitigates MIME type sniffing which can cause security vulnerabilities. https://github.com/helmetjs/helmet/tree/master/middlewares/x-content-type-options 03:28 - Explanation of 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 ... https://www.youtube.com/watch?v=3VhJH3zuZwc

If the numbers 1 to 5 are written out in words: one, two, three, four, five, then there are 3 + 3 + 5 + 4 + 4 = 19 letters used in total. If all the numbers from 1 to given limit inclusive were written out in words, how many letters would be used? Note: Do not count spaces or hyphens. For example, 342 (three hundred and forty-two) contains 23 letters and 115 (one hundred and fifteen) contains 20 letters. The use of "and" when writing out numbers is in compliance with British usage. Link to Challenge : https://projecteuler.net/problem=17 Full Playlist: https://www.youtube.com/playlist?list=PLhGp6N0DI_1RQjG0wIOi2afjuh9iIeHU6 Project Euler Written Guides : https://www.notion.so/ganeshh123/62598b647b6040f88843b33b46faa309 All My Tutorials can be found at : https://tutorials.gn3.sh -————————————————————————————————————- Project Euler (named after Leonhard Euler) is a website dedicated to a series of computational problems intended to be solved with computer programs. The project attracts adults and students interested in mathematics and computer programming. Since its creation in 2001 by Colin Hughes, Project Euler has gained notability and popularity worldwide. It includes over 700 problems, with a new one added once every one or two weeks. Problems are of varying difficulty, but each is solvable in less than a minute of CPU time using an efficient algorithm on a modestly powered computer. As of 5 April 2020, Project Euler has more than 1,000,000 users, from all over the world, who have solved at least one problem. NOTE: I am not a teacher by any means, these videos are just to help me improve my understanding. Thanks for Watching! ... https://www.youtube.com/watch?v=bM7bZh9EIJ8