Websites that were originally designed to share information and images have changed into web applications programs. Development of web apps is possible with the advent of new technologies such as JavaScript, DOM, AJAX, and REST. But web application development is not without its problems. Conversion from web pages to web applications requires the use of new programming principles because it is no longer about static web pages with text and images.
Web frameworks
With the advent of web applications, many web frameworks have also emerged in recent years. Although it is possible to develop web applications without these, it is a costly process. Web framework as a whole is a collection of components designed to facilitate the development of web apps. All are built with programming principles as a basis and must follow the MVC architecture design pattern. The idea is to allow web developers to focus on the important things instead of reinventing the wheel. So, some components can be reused.
Web Servers
It is a software component that can respond to an HTTP request. For a really basic static page, it can be done with just a one-page server. The web application server, namely the web application service, is relatively easy to understand. It is responsible for running the core business logic, handling user requests, and returning HTML to the user’s browser. In order to complete their work, they usually need to access a variety of backend services, such as databases, caches, job queues, and so on. The web application server must have a specific programming language (Java, Node.js, Ruby, PHP, Java, C # .NET, etc.).
Technologies for the development of web applications
HTML:
HTML is a plug-in language used to create websites. It allows the description of how the structure of a text-based document should be displayed on the browser. It encloses the text between HTML tags which defines the text and describes its design on the page. The tags describe which part of the text is a title, which is a paragraph and which parts are links, etc. The HTML tags command the structure of the page to the browser, and the browser uses it to display the text accordingly. Tags are invisible to users when the page is displayed in a browser. Such technologies as canvas were added to HTML5 to draw graphs and animations, disconnected data storage, and drag and drop functions.
JUDGMENT:
Document Object Model, commonly used under the abbreviation DOM, is necessary to make web pages interactive. We usually characterize the DOM as a tree of the objects (knots). It is a platform-independent way of describing the collection of objects, which constitutes one web page in a web browser. The DOM enables the JavaScript scripting language to be programmatic, examine and modify a web page. In other words, the DOM acts as an interface with JavaScript language can be used to manipulate the content, structure, and style of one web page.
JavaScript:
JavaScript is a dynamic programming language. It is used as part of web pages, which enables dynamic interaction between websites and their users. It is a high-level interpretive language that fits well with object-oriented programming style. Although the language is compiled while running in a browser, it is very fast. JavaScript’s programs are event-driven based and are non-blocked. JavaScript has, in recent years, also started being used as a server-side programming language. This is possible with the introduction of Node.js, which is built on the Google V8 JavaScript engine.
Some Trends in Web Application Architecture
Service-Oriented Architecture
As described in a service-oriented architecture, a service is a particular software function that is independent of other functions. For example, a bank’s software log necessarily includes a customer balance retrieval service, displaying a current balance at the bank’s request or the customer. Retrieve customer balance is a service. Following the bank’s lead, other services include deposit processing, withdrawal processing, and so on. In a service-oriented architecture, each of these services performs its work independently of the overall software system, using the same software system. This sounds counterintuitive, but in fact, it is not. Basically, different services use the same system to do the same thing and achieve different results. One of the keys to the success of service-oriented architectures is that the services themselves are looser. That is, they are adapted to different conditions. If service orders that receive customer credits suddenly become customer credits for all accounts, the software does not have to reinvent the virtual wheel. Instead, the service in question can achieve the same goals in different ways using the same basic protocol.
Single-Page Applications
Their essential advantage is that server requests might be limited. In the traditional approach, each user interaction with the page leads to a server request, and the browser has to reload the whole page. This disrupts the user experience. With the modern approach, the request goes straight to JavaScript event handlers. This way, the client stays on the same page during the whole session, requiring no new page reloads. If a link in the navigation bar that leads to a different page in the application is requested, everything is done in the browser by manipulating the DOM tree to display the new page. This could lead to a much more fluid user experience because the requests of the server can be avoided, and the browser does not have to reload the entire page. This principle is commonly referred to as a Single-page app.
Blockchain Network
Any application that works on the internet is served on the user’s computer using a browser or a particular application. In both cases, it requests the page or information from the server, which is then sent to the user’s computer. In terms of web applications, everything is centralized. This offers several advantages; however, this leaves a lot to be desired in terms of security. Blockchain applications work in a completely different way. Everything is decentralized, including the code and data stored in the app.
_Other trends: Progressive Web Apps and Prioritizing Search Engine Optimization.
What is Backend & Front-End Development?
_ Backend:
These are a set of commands that run on the server, i.e., “not in a browser” or “on a computer connected to a network (usually the Internet) that replies to messages from other computers”. The backend consists of: a server, an application, and a database. It is the work behind the scene—everything the users don’t see or interact with. Backend languages are: Ruby, PHP, Python, Java, and .NET. It also means using database management systems such as MySQL, PostgreSQL, MongoDB, Cassandra, Redis, and Memcached.
_Front-End:
It is the “client-side” development. The focus is on what users see first in a browser or an application and interact with. Front-end languages: HTML, CSS and JavaScript. Front-end development is to choose:
Type of Architecture: Choose (MVC), (SPA), or (SSR) for the application.
Platform: Angular, React, and Web Components technology suite, etc.
Database
Basically, modern applications must use several databases to store data. With the help of the database, we can easily carry out various processing operations on the data, e.g. updating data, deleting and computing data. In general, just like job servers, web application servers access the database directly. In addition, each backend service might require a separate database. The main potential for a NoSQL database is to perform operations on massive amounts of data that is not structured or connected in complex relationships. A document-oriented database is a data store that is based on documents that contain unstructured content. Documents are often separated into unstructured collections (can be viewed as SQL-tables), where unstructured here means that content in the same collection can have a different structure. Most popular database: MySQL, MongoDB, Redis, PostgreSQL.
API
An API defines an interface that exposes service data to other applications. Choosing the right API format is extremely important. Business does not always consider all factors when selecting a format. As a result, there is not enough opportunity to add new features that may be needed in the future. To save time, effort, and, most importantly, money, it is worth looking at the best practices that are currently being applied. This will help to develop an API that allows you to make the necessary changes in the future. Over the years, several API formats have appeared; consider the most popular of them. The most popular request-response APIs are REST, RPC, and GraphQL.
Web apps can perform better by having state and business logic in the client because it endorses the storage of database objects in the browser’s memory, reducing the amount of server calls needed. Once it must consult the server, it happens asynchronously in the background without the user noticing any delay because there is no blocking process. This has excellent scalability benefits also because the server doesn’t have to maintain session data in memory for every current user. Also, the thick-client architecture decouples the client from the server, which might facilitate replicating the backend, which is likely to improve the system’s scalability.
Some Educational Challenges and how to overcome them with EdTech solution from Serokell:
The majority of Serokell programmers are the tutors in the leading universities, familiar with many of the edtech issues and education process concerns, like:
Problem: Passive students
The challenge: Staying connected with students
Serokell Solution: Integration to the edtech platform virtual classrooms for interactive lectures with online Q&A sections, adding quizzes and discussion interfaces, and voting.
Problem: Lack of group collaboration, isolation of individuals while studying online
The challenge: Organize the group work remotely
Solution: Adding the facilities for online meetups, group discussion with online tools for mass communication, like sharing several screens, automate video recording, online chats, and admin panel for group work moderation.
Problem: Paperwork and formal evaluation
The challenge: Organize the monitoring of activity, evaluate the results, and identify struggling students
Solution: Providing the tools for online monitoring and auto reporting; introduction of self-checking interactive test and final assessment sessions; integration of real-time widgets and dashboards for representation of individual achievements or knowledge gaps, demonstration of aggregated results, and/or detailed statistics.
Problem: Corporate and personal data privacy
The challenge: Protect the personal data
Solution: With the introduction of distributed ledger technologies and formal verification, we can provide the information only to verified users while protecting the custom system from data leakage
