परिचय
सिस्टम में नवीनता लाने के लिए सॉफ्टवेयर इंजीनियरिंग एक प्राथमिक कौशल है। यह हमारे लिए परिवर्तन करने और लोगों के काम करने के तरीके में सुधार करने का एक प्रभावी तरीका है। यहां, हम वेब-आधारित सॉफ़्टवेयर इंजीनियरिंग का अन्वेषण करते हैं ताकि आपको हमारे कभी-कभी परेशान करने वाले मुद्दों में से कुछ को हल करने में मदद करने के लिए अंतर्दृष्टि और व्यावहारिक जानकारी मिल सके।
प्रारंभिक बिंदु के रूप में, यह पाठ्यक्रम उन छात्रों के लिए आदर्श है, जिन्हें प्रोग्रामिंग का बहुत कम या कोई अनुभव नहीं है, जो वेब आधारित सॉफ़्टवेयर इंजीनियरिंग के मूल सिद्धांतों को उजागर करना चाहते हैं। यह क्लाइंट (ब्राउज़र) और सर्वर-साइड आर्किटेक्चर, संबद्ध तकनीकी शब्दों की व्याख्या करता है और वर्ल्ड वाइड वेब प्रोग्रामिंग भाषाओं (PHP, JavaScript, SQL, CSS और HTML सहित) में व्यावहारिक ज्ञान प्रदान करता है। यह तकनीकी संरचना इंटरनेट का प्रतिनिधि है और सीखने के इस स्तर के लिए उपयुक्त है। एक बार आत्मसात करने के बाद, आपकी आवश्यकताओं के अनुरूप तकनीकी विविधताओं को चुनना आसान हो जाता है।
सॉफ्टवेयर इंजीनियरिंग सेमिनार आपको ऑनलाइन ट्यूटोरियल का उपयोग करके अपनी गति से प्रोग्रामिंग कौशल हासिल करने की जानकारी देता है। यह स्थानीय वेब सर्वर वातावरण की स्थापना से संभव हुआ है। यह सॉफ़्टवेयर आपको दूरस्थ वेब सर्वर के माध्यम से इंटरनेट का उपयोग किए बिना स्वतंत्र रूप से संचालित करने, अध्ययन करने, साझा करने और स्वतंत्र रूप से वेबसाइटों को विकसित करने की गारंटी देता है।
पाठ्यक्रम एक शुरुआती वेब आर्किटेक्चर शब्दकोश और वेब सॉफ़्टवेयर भाषा निर्देश तीन भागों में समूहीकृत करता है। भाग 1 - वेब ब्राउज़र सॉफ्टवेयर, भाग 2 - वेब सर्वर HTTP और PHP सॉफ्टवेयर और भाग 3 - वेब सर्वर डेटाबेस सॉफ्टवेयर।
यह लगभग अपरिहार्य है कि समय-समय पर सहायता की आवश्यकता होगी। इसलिए आपके पास कोई भी प्रश्न (चाहे कितना भी तुच्छ क्यों न हो) info@adt.vision पर भेजें - यह अंततः एक FAQ सुविधा का आधार बनेगा और दूसरों की मदद करेगा जो समान कठिनाई का अनुभव कर सकते हैं। सुझाए गए सुधार और संभावित त्रुटियों की सूचना का भी स्वागत है।
विचार करने के लिए कुछ लाभ
पाठ्यक्रम पूर्वापेक्षाएँ
कोई पूर्व सॉफ्टवेयर इंजीनियरिंग ज्ञान की आवश्यकता नहीं है, हालांकि बुनियादी इंटरनेट और विंडोज कौशल होने से मदद मिलेगी। प्रत्येक छात्र को, जहां संभव हो, अपने विंडोज 10 या 11 लैपटॉप (32 या 64-बिट सिस्टम प्रकार) की आपूर्ति करनी चाहिए। डिवाइस को क्रोम ब्राउज़र के साथ कॉन्फ़िगर किया जाना चाहिए और इसमें लगभग 3GB उपलब्ध स्टोरेज स्पेस होना चाहिए। किसी भी सॉफ़्टवेयर को स्थापित करने से पहले अपने लैपटॉप को मैलवेयर के लिए Windows सुरक्षा एप्लिकेशन से जांचें। एंटीवायरस सॉफ़्टवेयर को IDE स्थापित करने से पहले और बाद में यह विश्वास दिलाने के लिए चलाया जाता है कि खतरे के स्तर से समझौता नहीं किया गया है।
Terminology Review
You may know the meaning of some of the following terms, or at least you may have heard of them. Make an attempt to digest each term in turn and make a note of the things that you find difficult to understand. Wherever possible, we will resolve your queries. Also, these terms will make more sense as and when we take a look at practical examples; a good opportunity for further clarification.
Don't be put off. The idea is to feel at ease with these terms when we reach the end of our course. Any additional worthy terms that we discover will be added, along with their corresponding technical descriptions as needed, for completeness.
Each term has a calibration function that allows self assessment by rating your understanding of the associated narrative. We will ask you to review this at regular intervals throughout the course to give an at-a-glance indication of your overall progress.
Browser
All users access the web through web browser software, which is included on computers and mobile devices at the time of purchase. Other browsers can be downloaded from the internet. A browser is a free software package or mobile app that displays web pages, graphics, and most online content. Popular web browsers include Chrome, Firefox, Internet Explorer, Microsoft Edge, and Safari, but there are many others. Browser software is specifically designed to convert HTML and XML computer code into human-readable documents. Browsers display web pages. Each web page has a unique address called a URL (see below).
Localhost
A localhost is the standard host name provided to the address of the local computer in computer networking. The localhost denotes the host name used in communicating with the loopback network interface; that is, with software on the computer that originated the transmission.
Let's say you wanted to call your own cellphone to test a ringtone you created. You could dial your telephone number to see what happens. However, you'd have to dial the entire number as it goes out throughout the cellphone network, as if you're calling any outside number. What if instead you could simply punch in a name like "thisphone" and it would work, as if you dialed your number and routed it via the network normally?
When you try to establish a network connection to the localhost (loopback) address, it avoids connection to the local network interface hardware (and therefore doesn't require internet access). The bulk of our development and testing will be conducted using localhost. We will take a look at how we configure a localhost in a later tutorial. Local and Remote Host ⇒
Remote Host
A computer that resides in some distant location from which data is retrieved. Web site hosting is the business of housing, serving, and maintaining files for one or more Web sites. The remote host I use is provided by iPage. So, for example, my website files (for www.itgis.org) are stored on one of iPage's computers in California.
Cloud hosting is and alternative way to host a website's files and offers unlimited resource expansion, which is great to have if you have a fast-growing site. Your site will also be shielded from malfunctioning servers, as your site can be switched to another server if it's underperforming. Remote and Local Host ⇒
ISP
You need an Internet Service Provider (ISP) to get to the internet. You may access a free ISP at school, a library or work, or you may pay for a private ISP at home. An ISP is the company or government organization that plugs you into the vast internet. An ISP offers a variety of services for a variety of prices: web page access, email, web page hosting, and so on. Most ISPs provide various internet connection speeds for a monthly fee. You may choose to pay more for a higher-speed internet connection if you like to stream videos or select a less expensive package if you use the internet mostly for light browsing and email. An example ISP Virgin Media ⇒.
Router
A router or router-modem combination is the hardware device that acts as the traffic police for network signals arriving at your home or business from your ISP. A router can be wired or wireless or both.
IP Address
Your computer and every device that connects to the internet uses an Internet Protocol address for identification. In most cases, IP addresses are assigned automatically. To find your IP Address click here ⇒. There are currently two version of Internet Protocol (IP): IPv4 and a new version called IPv6. The local or internal IP address is the address that is assigned by your local network router. Local IP addresses can only be seen by other computers in your local network and not by any computers connected in an external network such as on the Internet. On almost all networking systems, localhost uses the IP address 127.0. 0.1. That is the most commonly used IPv4 "loopback address" and it is reserved for that purpose. The IPv6 loopback address is ::1.
Domain Name
Domain names are easy-to-remember words that we can use to tell a DNS server the website we want to visit. The Domain Name System (DNS) is what translates the friendly name to an IP address.
.org is a top-level domain name (TLD)
itgis.org is a second-level domain name (SLD)
sagesse.itgis.org is a third-level or three-part domain name
project.sagesse.itgis.org is a fourth-level or four-part domain name
A top-level domain name is never used by itself. It is always combined with at least a second-level domain name.
URL
Uniform Resource Locators are the web browser addresses of internet pages and files. A Uniform Resource Identifier (URI) is a string of characters that unambiguously identifies a particular resource. The most common form of URI is the Uniform Resource Locator (URL), frequently referred to informally as a web address.
The URL for my website is https://www.itgis.org. URLs consist of multiple parts including a protocol and domain name that tell a web browser how and where to retrieve a resource.
See also IBM Overview ⇒
A web server is also known as an internet server.
HTML
Hypertext Markup Language (HTML) is the universal programming language of web pages. HTML lets you format text, add graphics, create links, input forms, frames and tables, etc., and save it all in a text file that any browser can read and display.
CSS
Cascading Style Sheets (CSS) is a style sheet language used for describing the presentation of a document written in a markup language such as HTML. CSS is a cornerstone technology of the World Wide Web, alongside HTML and JavaScript.
JavaScript
A JavaScript developer is responsible for implementing the front-end logic that defines the behavior of the visual elements of a web application. JavaScript is a scripting language used to make web pages interactive (say, popup menus). JavaScript developers often work alongside other web developers who specialize in HTML markup and CSS styling.
PHP
PHP is a type of open-source general-purpose scripting language fit for server-side programming. It is a popular choice in web development in creating dynamic pages and applications.
PHP is a type of interpreted language; no compilation is necessary. It works for server-side development. It is an object-oriented open-source scripting language. It is possible to embed PHP into HTML. Developers, beginner-level and experienced, can learn PHP quickly.
There are multiple uses of PHP that make it a strong scripting language option for web development. It operates over the web server and then processes all client requests into HTML files. Additionally, PHP is a general-purpose language; developers can use it to code for different applications.
In the context of website development, choosing the right kind of scripting language would determine the quality of the web solution. PHP is a well-known option for web development, with almost 80% of websites running on this framework.
Hypertext
Hypertext is text displayed on a computer display or other electronic devices with references to other text that the reader can immediately access. Hypertext documents are interconnected by hyperlinks, which are typically activated by a mouse click, keystroke, or by touching the screen.
Preprocessor
A preprocessor is a program that processes its input data to produce output that is used as input to another program. For example: PHP: Hypertext . Prepocesor is a scripting language web developers use to create dynamic websites. When a website visitor accesses a PHP page, the web server processes, or parses, the PHP code, which can output HTML to the webpage. It is often installed by default on Apache web servers, alongside MySQL as part of a WAMP or MAMP configuration. When a website visitor accesses a PHP page, the web server processes, or "parses," the PHP code, which can output HTML to the webpage.
Protocol and HTTP
A standard procedure for regulating data transmission between computers, for example, TCP/IP, or the Transmission Control Protocol/Internet Protocol, is a suite of communication protocols used to interconnect network devices on the internet.
TCP/IP describes rules for dividing messages into small pieces, called packets; providing addresses for each packet; checking for and detecting errors; sequencing packets; and regulating the flow of messages along the network. Connections must be properly established in a multi-step handshake process (connection establishment) before entering the data transfer phase. Hypertext Transfer Protocol (HTTP) is a member of the TCP/IP family. It is part of the Internet protocol suite that defines commands and services used for transmitting webpage data and might read something like:
Browser: "I'm about to send a message" Localhost: "Is that you making a request" Browser: "Yes It's Me" Localhost: "Send it then;" Browser: "That's it sent." Localhost: "I acknowledge that you've sent a message" Browser: "I'm waiting for confirmation that you received the message" Localhost: "Message received OK (response status 200)".
Web Server
A web server is a system that delivers content or services to end users over the internet. A web server consists of a physical server, server operating system (OS) and software used to facilitate HTTP communication.
Requests, Responses and
Resources
The Hypertext Transfer Protocol (HTTP) is designed to enable communications between clients and servers. HTTP works as a request-response protocol between a client and server. A web browser may be the client, and an application on a computer that hosts a web site may be the server. HTTP is used to transmit resources (almost anything that can be obtained via the Internet), the R in URL. HTTPS is used for secure communication over a computer network.
Example: A client (browser) submits an HTTP request to the server; then the server returns a response to the client. The response contains status information about the request (used internally) and may also contain the requested content.
All HTTP response status codes are separated into five classes (or categories). The first digit of the status code defines the class of response. The last two digits do not have any class or categorization role. There are five values for the first digit:
1xx (Informational): The request was received, continuing process
2xx (Successful): The request was successfully received, understood and accepted
3xx (Redirection): Further action needs to be taken in order to complete the request
4xx (Client Error): The request contains bad syntax or cannot be fulfilled
5xx (Server Error): The server failed to fulfill an apparently valid request
There are several different ways (methods) to make an HTTP (HTTPS) request. Two of the most common are GET and POST.
GET requests a representation of the specified resource (for example, click https://itgis.org/compliance.php?o=portuguese note in this case the resource (and response content) is 'portuguese' and https://itgis.org/compliance.php?o=deutsch where the resource and response content is 'deutsch').
POST submits the data to be processed (say, some user specific details as typed into a Web page: Name, DOB and so on) to an identified resource (URL).
Essentially GET is used to retrieve remote data (after a ? in the URL), and POST is used to insert/update remote data enclosed in the body of the request message.
WAMP
The first practical task is to install this free (open source) server on the hardware device (localhost).
The acronym WAMP refers to a set of applications, combined with Microsoft Windows, which are commonly used in Web server environments.
The acronym MAMP is for Apple MacOS.
The WAMP/MAMP stack provides developers with the four key elements of a Web server: an Operating System, Database, HTTP Server and Scripting Language. The Hardware is the physical component of the computer system in which the stack resides. The combined usage of these programs is called a server stack. In this stack;
Windows or MacOS
Microsoft Windows or Apple macOS. Both the Mac and Windows operating systems have their strengths and flaws. The decision on which one to use solely depends on the user's technical skills and security requirements.
Apache
Apache is the most widely used web server software. Developed and maintained by Apache Software Foundation, Apache is an open source software available for free. It runs on 67% of all webservers in the world. It is fast, reliable, and secure. It can be highly customized to meet the needs of many different environments by using extensions and modules.
Apache is the software that receives your request to access a web page. It runs checks on your HTTP request and takes you to the web page. Depending on the page you have requested, the page may ask the server to run a additional programs (say, PHP and MySQL modules) while generating the document to serve you. It then serves you the document you requested.
While a web server is an essential part of any website, it’s important to note that we are unlikely to interact directly with the Apache HTTP web server. In other words Apache will normally function seamlessly in the background.
MySQL
A database is a separate application that stores a collection of data. Each database has one or more distinct programs for creating, accessing, managing, searching and replicating the data it holds. Other kinds of data stores can also be used, such as files on the file system or large hash tables in memory but data fetching and writing would not be so fast and easy with those type of systems.
MySQL (My Structured Query Language) is an Oracle-backed open source Relational Database Management System (RDBMS) based on Structured Query Language (SQL). SQL is the most popular language for adding, accessing and managing content in a database.
PHP
PHP is a popular general-purpose scripting language that is especially suited to web development. Fast, flexible and pragmatic, PHP powers everything from your blog to the most popular websites in the world.
A PHP (Hypertext Preprocessor) developer is responsible for writing server-side web application logic. PHP developers usually develop back-end components, connect the application with the other (often third-party) web services, and support the front-end developers by integrating their work with the application.
Base Software Stack (Video)
Click to view another perspective ⇒ Note LAMP (Linux Operating System) and IIS (Internet Information Server - Microsoft's Webserver) are mentioned in this video. They simply identify common alternatives to our WAMP stack configuration.
Operating System
Software that controls the functionality of a computer and directs the processing of programs by assigning storage space in memory and controlling input and output functions. Say, Apple's macOS or Microsoft's Windows 10 or 11. Open Popup ⇒
Static and Dynamic Web Pages
Web pages can be either static or dynamic. "Static" means unchanged or constant, while "dynamic" means changing or lively. Therefore, static Web pages contain the same prebuilt content each time the page is loaded, while the content of dynamic Web pages can be generated on-the-fly.
Standard HTML pages are static Web pages. They contain HTML code, which defines the structure and content of the Web page. Each time an HTML page is loaded, it looks the same.
The only way the content of a purely HTML page will change is if the Web developer updates and publishes the file. However, embedding JavaSript code within HTML makes it possible to implement dynamic "browser-side" code for example to display the current time and date on the Web page.
Other types of Web pages, such as PHP pages are dynamic Web pages. These pages contain "server-side" code, which allows the Web server (or in our case localhost) to generate unique content each time the page is loaded.
For example, the server may output a unique response based on a Web form the user filled out. Many dynamic pages use server-side code to access database information, which enables the page's content to be generated from information stored in the database.
DOM Document Object Model
When a web page is loaded, the browser creates a Document Object Model (DOM) of the page. The DOM is a programming interface that works with JavaScript to manipulate HTML document content. It allows programs and scripts to dynamically access and update the content, structure, and style of a document. We will explore this idea further with practical programming examples.