#Dependency Inversion Principle

[arifinfrds-blog]

The Dependency Inversion Principle (DIP) is a fundamental concept in software development that helps create flexible and maintainable code. In this article, I'll explore its history, the problem of tight coupling, and different approaches to applying DIP in Swift.

[kaiasky]

feel like some enterprise "java"-inflected developers and/or "medium writers who purport to talk about code patterns" live in an alternate world where their goal is to create Intricate Structures and not. to ship a fuckin product.

[talonabraxas]

Veil upon Veil you hide The well-spring of the Infinite, The blue that delights, Pierces the heart, And produces a sapphire jewel.

Celestial Deity Talon Abraxas

"The light of the sun is the source of the colour we see reflected in the world. It begins in gamma rays whose wavelengths are a million times too short to see. By a process of absorption and re-emission throughout the sun's body, these spread out into longer wavelengths which travel through space and are further altered by interaction with the atmosphere. If there are no dusts or gases in the heavens, the sky appears black, as it does ten miles out from the earth's surface where the atmosphere thins out almost to the vanishing point." The old man adjusted himself in the chair and continued: "The colour of the sky, child, is closely associated with the way light, falling on matter, is scattered in all directions. The amount of scattered light is greater for shorter blue wavelengths than for longer red ones." Here the learned mariner became more technical and spoke slowly, using his hands to explain. "The intensity of scattered light is inversely proportional to the fourth power of the wavelength. Because of this, blue light loses more energy than red and its scattering is dependent upon low atmospheric content. In the atmosphere of the earth, molecules of gases scatter the blue waves in all directions while the red waves are absorbed, causing the sky to appear blue. The more rarefied the air, the greater the scattering of these short waves and the deeper the colour of blue. But when there is considerable dust or moisture in the air, the layers of particles scatter the longer red waves and cause the sky to become whiter. The red and blue light mixes to produce the whitened sky so common in higher latitudes where moisture particles hang in the air. So the dust rising in a hot, dry clime bleaches out the heavens until a heavy rain settles the earth and leaves behind it a deep saturated blue. Men long for that blue, child. They always dream of travelling south into the azure intensity that has inspired poets and painters for countless years. So thus they gaze out over the horizon as you do, trying to penetrate its vastness."

“Blue color is everlastingly appointed by the deity to be a source of delight.” — John Ruskin

Appointed by the Deity, it is the abode of the gods, their intrinsic attribute and celestial surrounding. It is the colour of the Queen of Heaven and the feminine principle of the Great Deep. It veils the impenetrable void of chaos and yet recedes into its folded mystery. It is the colour of the cloak of Hera and Zeus and clings to Diana's fleet, forested shape. It is reflected in the blue robes once worn by priests at the grave and by the Levites who called their garb the livery of heaven. 'The Blue' is a synonym for heaven and all that is divine. In the darkened depths of its expanse lies Nature's solitude, wrapped in a cold noumenal glow whose purity is incomparable. By its grace, the sea takes on its colour and draws the ocean of space into the world, but the purity of 'the Blue' remains aloft to be viewed from mountain tops on perfectly clear and blessed days.

[srbachchan]

DAY 5974

Jalsa, Mumbai June 26/27, 2024 Wed/Thu 12:56 am

🪔 ,

June 27 .. birthday wishes to : Ef Ravi Patel .. Ef Diyansh Kumbhat from Chennai .. and .. Ef Ayush Mishra from Bilaspur .. 🙏🏻❤️🚩

💍 .. wedding anniversary greeting to : Ef Rajesh Kejriwal from Kolkata .. completing 35 years of togetherness .. on June 26 .. our wishes and more .. 💐🙏🏻❤️🚩

..

Birthday - EF - Ravi Patel Thursday, 27 June our wishes for this day and the best ever .. love ❤️

Resistance .. its many forms and values and dimensions and usage .. so it became urgently important to apprise the self of it from sources ..

"Resistance is a multifaceted concept, encompassing physical, psychological, social, and political dimensions. Its definition and application can vary significantly depending on the context in which it is considered. At its core, resistance involves the act of opposing, withstanding, or striving against some force or condition. This broad definition can be applied to various fields, including physics, medicine, psychology, and social movements.

In physics, resistance is a measure of the opposition to the flow of electric current in a conductor. It is quantified by the unit ohm and symbolized by the Greek letter omega (Ω). The resistance of a conductor depends on its material, length, cross-sectional area, and temperature. For instance, materials like copper and aluminum have low resistance and are therefore good conductors, whereas materials like rubber and glass have high resistance and are good insulators. Ohm's Law, a fundamental principle in electrical engineering, states that the current flowing through a conductor between two points is directly proportional to the voltage across the two points and inversely proportional to the resistance. This relationship is crucial in designing electrical circuits and understanding their behavior.

In medicine, resistance often refers to the ability of microorganisms, such as bacteria and viruses, to withstand the effects of drugs that are intended to kill or weaken them. Antibiotic resistance is a significant public health concern, as it makes infections harder to treat, leading to longer hospital stays, higher medical costs, and increased mortality. Resistance can develop through various mechanisms, such as genetic mutations or the acquisition of resistance genes from other bacteria. The overuse and misuse of antibiotics in humans and animals accelerate this process, making it imperative to use these medications judiciously and to develop new treatments.

Psychologically, resistance can manifest as a reluctance or refusal to accept certain thoughts, feelings, or behaviors. This concept is particularly relevant in therapy and counseling, where clients may resist discussing painful or traumatic experiences. This resistance can be conscious or unconscious and can hinder the therapeutic process. Understanding and addressing resistance is crucial for therapists, as it can provide insights into the client's internal conflicts and defenses. Techniques such as building a strong therapeutic alliance, using motivational interviewing, and gradually exposing clients to difficult topics can help in overcoming resistance.

In social and political contexts, resistance is often associated with efforts to oppose and challenge established power structures, policies, or social norms. Throughout history, resistance movements have played pivotal roles in advocating for social change and justice. Examples include the civil rights movement in the United States, the anti-apartheid struggle in South Africa, and the women's suffrage movement. These movements often involve a combination of nonviolent protest, civil disobedience, and sometimes armed struggle. The success of these movements typically depends on various factors, including leadership, organization, public support, and the ability to adapt to changing circumstances.

In contemporary times, resistance continues to be a vital force in addressing issues such as climate change, systemic racism, and economic inequality. Activists and grassroots organizations worldwide are mobilizing to resist policies and practices that they perceive as unjust or harmful. Social media and digital communication have transformed the landscape of resistance, enabling rapid dissemination of information, coordination of actions, and amplification of marginalized voices.

Resistance, in its many forms, is an essential aspect of human experience and societal development. Whether in the realm of science, health, psychology, or social justice, resistance challenges the status quo and fosters progress. It embodies the struggle for survival, dignity, and betterment, reflecting the resilience and determination inherent in individuals and communities. As such, understanding and engaging with the concept of resistance is crucial for addressing the complex challenges of our world. "

... and at times the sources do not even address the most common of them all in the resistance ..

It be the pen and paper writing ..

When the pen has a resistance to the paper quality it is being written on the writing experience is determined as good bad or average ..

When the holding posture of the pen is conveniently comfortable to write, it produces the quality of writing exhibited ..

When the nib and flow of the ink on the pen is of desired like , the paper may be of the best resistance quality, the writing shall never be of the desired ..

paper same .. nib different , pen different .. sign same , but all different in form and appearance ..

GN 😴

Amitabh Bachchan

[arabellas-inferno]

Satanic rituals & symbolism

Satanic rituals and symbolism can vary depending on the specific branch or individual's beliefs within Satanism. Here is some general information about common elements found in Satanic rituals and symbolism:

Rituals: Satanic rituals are often performed as a means of personal expression, self-transformation, and psychological empowerment rather than as acts of literal worship. These rituals may involve the following elements:

Altar: A central focal point where various symbolic objects are placed. The altar can represent the practitioner's connection to their personal beliefs or philosophy.

Candles: Candles are commonly used to create a ceremonial atmosphere and represent illumination, enlightenment, or specific intentions.

Invocations: Satanic rituals may include invocations, which are spoken or written requests or affirmations addressed to certain symbolic entities or forces. These invocations may aim to align the practitioner with specific energies or personal goals.

Symbolic Gestures: Certain symbolic gestures or movements may be performed during rituals to reinforce intentions, evoke specific energies, or create a desired psychological or emotional state.

Symbolism: Satanic symbolism often incorporates a range of esoteric and occult symbols. Here are some commonly used symbols within Satanic practices:

Inverted Pentagram: The inverted pentagram, with the point facing downward, is a widely recognized symbol in Satanism. It is often associated with rebellion, the rejection of conventional morality, and the embracing of personal freedom.

Baphomet: The Baphomet is a symbol depicting a winged humanoid figure with a goat's head. It is often associated with Satanism and represents duality, wisdom, and the union of opposites. The Baphomet is sometimes used as a representation of Satanic principles or as a focal point during rituals.

Sigil of Baphomet: The Sigil of Baphomet is a specific symbol that consists of an inverted pentagram with additional elements, such as the Hebrew letters for "Leviathan" and "Lucifer." It is widely recognized as a symbol of Satanism and is often used to represent Satanic ideals and beliefs.

Black Mass: The Black Mass is a ritual that mocks or parodies the Catholic Mass. It is a controversial and provocative practice that may involve the inversion of traditional religious symbols, blasphemy, or other acts intended to challenge religious norms and conventions.

It is important to note that while Satanic rituals and symbolism may appear dark or sinister to some, they are often used as symbolic expressions of personal beliefs, philosophies, or as forms of self-expression.

Most Satanists do not engage in harmful or criminal activities and instead focus on personal empowerment, individualism, and the rejection of societal norms.

Please remember that my explanations are intended for informational purposes only, and it is essential to respect the diverse beliefs and practices within Satanism.

[ubese-language-databank]

Introduction to the Ubese Language

Welcome to the Ubese Language Databank! We will be posting one Ubese word of the day each day. Ubese consists entirely of verbs, so all you need to know is how to conjugate them. In this introductory post, we will cover the alphabet and various aspects of grammar. Each word of the day will showcase the definition and conjugation of each verb. Ia-to! Tages! (Let's begin!)

Alphabet and Punctuation

The Ubese alphabet is simple, consisting only of fourteen letters and three punctuation marks. Stress in vital in Ubese for distinguishing between different words, such as "ya-tei," meaning "I concur," vs "yatei," meaning "dismember me." Stress falls in an alternating pattern— for example, "ya-teiset-ga," meaning "they are not agreeable," is stressed on the even-numbered syllables, while "yateis-etga," meaning "they are not separated," is stressed on the odd-numbered syllables.

Topic Markers

Topics in Ubese indicate the the subject or object of the sentence, depending on whether the verb that follows is active or passive. For example, "o, ta-chei" means "I hear you," while "ei, tasho" means "you are heard by me." The topic marker is often voiced as a comma in spoken Ubese and is transliterated in Basic accordingly. Not every Ubese construction requires a topic— for example, "ta-chei" means "my ears work perfectly." Third person verbs are inflected with either animate or inanimate pronouns. Sentient beings, droids, animals, and plants are considered animate; all other objects are considered inanimate.

Suffixes

Negative suffixes in Ubese negate a given verb. For example, "a, ta-cheitga" means "I didn't hear that," and "edchat-ga" means "that is not edible."

Optative suffixes in Ubese express a desire for something to occur or be true; for example, "os, yo-teish" means "I want to show you something," and "udis-esh" means "may they learn."

Polite suffixes soften an otherwise direct verb form. For example, "a, yuh-to" means "give me that," while "a, yuh-tocha" means "please pass the bloodworms."

Adjectival suffixes turn verbs into descriptions, which generally serve the role of nouns in Ubese. For example, "a, eg-teis" means "we eat," while "eg-taza" means "food," or literally, "it is for eating."

Mathematics

Ubese is a highly contextual language with no actual root nouns. Thus, they do not have base cardinals. Instead, numbers are expressed in terms of arithmetic. For example, to say "I would like to buy four jogans for one credit," one would say "a, de-go. Ei, ze-gei," or, "add four jogans to my cart, I will add one credit to your pocket." Inverse operations are expressed in negatives; for example, to say "I will only give you half that much," one would say, "O, gyuh-tatga," or, "divide the amount of jogans by two."

You now understand the complete workings of Basic Ubese grammar! With these construction principles, you can conjugate any verb in the Ubese lexicon. Yu-gyosesh-cha! (I hope this lesson was satisfactory!)

[1yyyyyy1]

Tips & tricks on how to stop giving a fuck about other people, specifically their feelings and chimpout reactions, if you're sensitive to that stuff?

This is a complex topic. You can become sensitive to people's reactions for quite a few reasons, ranging from mild workplace disagreements to severe trauma. The most effective approach will depend on the cause. As such, I will always advise to consult a qualified professional if it is possible. The following is what found helpful in my own introspection and what I personally find important to understand about mental health.

Do you have these moments in your life where, long after a conflict subsided, you replay an event in your head wishing you had retorted with something clever? Do you find yourself thinking how stupid you are for being bothered by something this petty? Is your immediate decision to shut your eyes tight and wish for it to go away? Don't. Stop in your tracks and finish your line of thought. A disturbance like that is not petty. In situations where retaliation is not an option for a variety of reasons, be it the danger of calling out your superior, or simply because the opportunity is long gone, people tend to not only opt out of confrontation, they opt out of experiencing the related emotional feedback as well. How often do you feel that your anger is useless? That the situation is simply too dire to be resolved with a simple display of emotion, and that expressing your displeasure would be a waste of time? Anger is an indication that something is wrong, and it is useless for as long as you devalue yourself and your own biological processes. The reaction you wish you had had has not gone anywhere, you are simply suppressing it over and over again, just like you did during the incident. Recalling it in an untimely manner is what the brain does in an attempt to process the event in earnest.

The solution comes down to the following psychological phenomenon: it does not matter to your brain whether the person you are referring to is real or imaginary, it treats them all the same. If it is not safe for you to confront the person, do it retrospectively and it will have a similar effect relieving emotional tension. The same principle applies to situations where it is dangerous for you to express your disdain outright: dealing with an abusive ex-boyfriend, your parents threatening to evict you should you make a fuss. You can see me refer to an imaginary person in this post as to avoid a spat and let off steam all the same. I have had women confide me in the fact that they talk to themselves in private, and it is crucial to recognize what this process functionally is. Do not deny yourself this on the premise that it is stupid or bizarre. Whenever you catch yourself slipping into an unpleasant memory, take a step back and play out the event as if it were real. Defend yourself to the best of your ability and don't mince words. I assure you, you will not only feel better, you will no longer be haunted by the incident soon after the exercise is over.

If I were you, I would ask myself this: Why do I care? Why do I care about people's feelings? Why do I feel like I have to take them into consideration?

Many a thing with insecurities are an inverse trauma response. It is easier to assume that you breaking down means you are unfit for the job, and not that your supervisor is a bully. It would require reflecting on the circumstances that led up to the moment: financial instability, fear of losing the job, a potentially triggered flashback; that in itself is traumatic. The best thing you can do is not make an enemy of yourself. Few a person has your best interest in mind. Now is not the time to be insecure.

I do not care about people’s opinions and feelings because their input is of limited value to me. Living by this world’s principles has never worked for me, it is stupid to assume that it will now. A common concern I have seen women express over consistently making a harsher judgement is that they will end up not having enough self-awareness not to go overboard, and that they will needlessly hurt the people around them and themselves in the process. The truth is that people who are malignant behaviorally do not ask themselves these questions, and they certainly do not consider themselves being at fault a possibility. With a smidge of awareness, you are good to go.

[techpointfundamentals]

Dependency Inversion Principle of SOLID Principle:

Q01. What is Dependency Inversion Principle (DIP) of SOLID? Q02. What is Inversion of Control (IoC)? Q03. What is Dependency Injection (DI)? Q04. What is IoC Container? Q05. What is Coheson vs Coupling?

Please visit www.techpointfunda.com for more Interview Questions and Answers.

[codingbrushup]

Coding Brushup for Java #10: Best Practices & Tips

In the fast-evolving world of software development, writing clean, efficient, and maintainable code is paramount. For Java developers, adhering to best practices not only enhances code quality but also ensures scalability and ease of collaboration. This guide delves into essential Java coding best practices, offering actionable insights to elevate your programming standards.

1. Embrace Meaningful Naming Conventions

Clear and descriptive names for classes, methods, and variables significantly improve code readability and maintainability. Avoid ambiguous names like temp or data; instead, opt for names that convey purpose, such as calculate Total Price or user Age. Consistent naming conventions also facilitate smoother collaboration among developers.

2. Adhere to the DRY Principle (Don't Repeat Yourself)

Repetition in code leads to redundancy and increases the risk of errors. By creating reusable methods or classes, you can eliminate duplicate code, making your codebase more concise and easier to maintain. For instance, instead of duplicating validation logic across multiple methods, centralize it in a single utility class. ​

3. Implement the Single Responsibility Principle (SRP)

Each class should have one reason to change, meaning it should only have one job or responsibility. By ensuring that classes are focused on a single task, you enhance code clarity and make it easier to modify or extend functionality without unintended side effects. ​

4. Utilize Exception Handling Wisely

Proper exception handling is crucial for building robust applications. Avoid using exceptions for control flow; instead, catch specific exceptions and handle them appropriately. Employ try-with-resources statements to manage resources like file streams, ensuring they are closed automatically. ​

5. Leverage Java Streams and Lambda Expressions

Introduced in Java 8, Streams and Lambda expressions allow for more concise and readable code, especially when dealing with collections. They enable functional-style operations like filtering, mapping, and reducing, which can simplify complex data processing tasks. ​

6. Prioritize Code Readability

Code is often read more frequently than it's written. Therefore, prioritize readability by using consistent indentation, meaningful comments, and clear logic. Avoid deep nesting and complex conditionals; instead, break down complex methods into smaller, more manageable ones. ​

7. Follow the SOLID Principles

The SOLID principles are a set of five design principles that promote object-oriented design and programming:​

Single Responsibility Principle (SRP): A class should have one, and only one, reason to change.​

Open/Closed Principle (OCP): Software entities should be open for extension but closed for modification.​

Liskov Substitution Principle (LSP): Objects of a superclass should be replaceable with objects of its subclasses without affecting the correctness of the program.​

Interface Segregation Principle (ISP): No client should be forced to depend on methods it does not use.​

Dependency Inversion Principle (DIP): High-level modules should not depend on low-level modules. Both should depend on abstractions.​

Adhering to these principles leads to more modular, flexible, and maintainable code. ​

9. Optimize Performance Thoughtfully

While it's important to write efficient code, premature optimization can lead to unnecessary complexity. Focus on writing clear and correct code first; then, profile and optimize performance-critical sections as needed. Utilize tools like JProfiler or Visual VM to identify bottlenecks in your application.​

Conclusion

By integrating these best practices into your Java development workflow, you can produce code that is clean, efficient, and maintainable. Remember, the goal is not just to write code that works, but to write code that is easy to understand, modify, and extend. Continuous learning and adherence to these principles will set you on the path to becoming a proficient Java developer.​

Read Original Source- https://codingbrushup.com/coding-brushup-for-java-10-best-practices-tips/

[kalifissure]

WARNING! CRACKPOT PHYSICS!

**Neutron Decay Cosmology (NDC)** is a cosmological model where the expansion of the universe is driven by the decay of free neutrons in deep voids, while gravitational collapse at event horizons provides the necessary counterbalance. Instead of a one-time Big Bang, the universe is **homeostatic**, continuously expanding and contracting through a natural feedback cycle.

### **Core Principles of Neutron Decay Cosmology**

1. **Expansion via Neutron Decay:**

- In deep cosmic voids, where pressure is low, free neutrons decay into protons and electrons, leading to an extreme expansion in volume.

- A single neutron (initial volume ~0.6 fm³) decays into a proton-electron complex, stabilizing into amorphous hydrogen with a volume increase of ~\(10^{15}\).

- This massive volume expansion in voids drives what we perceive as **cosmic acceleration** (akin to dark energy).

2. **Compression via Gravitational Collapse:**

- At high-density regions (e.g., neutron stars, black holes), gravity forces electrons into protons, reversing the decay process via **electron capture**, forming neutrons again.

- When a neutron star collapses beyond a critical density, individual neutron identities merge into a singular event horizon, reducing cosmic volume.

- This contraction counters the expansion from neutron decay, maintaining overall **homeostasis**.

3. **Compactified Time & Shirley’s Surface:**

- Time is **compactified over a single Planck second**, meaning there is no external time—just local density-dependent flow.

- The universe is structured as **Shirley’s Surface**, a **single-sided topological manifold** where expansion and contraction connect via a node.

- This results in two apparent "oppositional" regions—matter and antimatter—linked through **renormalization at infinity**.

4. **Matter & Antimatter as Opposites Across the Surface:**

- The event horizon acts as a **closure point** where the matter side (our universe) meets its antimatter counterpart.

- The flow of matter through the surface is cyclic: Neutrons decay into protons/electrons → hydrogen forms → stars create heavier elements → collapse forces re-neutronization.

- This model explains **why antimatter isn’t seen**—it’s the inverse side of Shirley’s Surface, not annihilating in our domain.

5. **Space as a Thixotropic Dielectric Superfluid:**

- Gravity is the **local flow rate** of this superfluid, which has maximum curvature at Planck scales.

- Electrons and positrons are **outflows and inflows** on Shirley’s Surface, explaining charge and spinor behavior.

- Photons are toroidal **propagating Marangoni currents** in time, while neutrinos are pure spin-aligned z-axis flows.

### **Key Predictions of Neutron Decay Cosmology**

- **Dark Energy = Expansion from Neutron Decay**

- **Dark Matter = Granular Proton-Electron Hydrogen Soup**

- **Cosmic Homeostasis = Expansion in Voids + Collapse at Event Horizons**

- **Antimatter Exists, but on the Inverse Side of Shirley’s Surface**

This model offers an alternative to inflation, heat death, and singularity-based cosmologies by treating the universe as a **self-regulating fluid flow system** instead of a one-time explosion or contraction.

[techsoundwave]

Лучшие практики кодирования: как писать чистый и поддерживаемый код

Как разработчик программного обеспечения, работающий в стартапе, я сталкиваюсь с множеством вызовов каждый день. Особенно это касается разработки мобильных приложений, где важно не только быстро запускать продукт, но и обеспечивать его долгосрочную поддержку и масштабируемость. Писать чистый и поддерживаемый код — это не просто хороший стиль, это необходимость для успешной разработки и дальнейшей работы над проектом.

1. Чистота и читаемость кода

Первая и, пожалуй, самая очевидная рекомендация — пишите код так, чтобы его было легко читать и понимать. Это включает в себя правильные наименования переменных, функций и классов. Имя должно сразу давать понять, что делает этот элемент. Например, переменная userAge намного понятнее, чем ua. Важно помнить, что код пишется не только для компьютеров, но и для людей, которые будут его читать.

Кроме того, стоит избегать длинных и сложных функций. Принцип единственной ответственности (Single Responsibility Principle) говорит о том, что каждая функция или метод должны выполнять только одну задачу. Если метод становится слишком большим, лучше разделить его на несколько более мелких и понятных.

2. Использование комментариев и документации

Хотя многие считают, что комментарии в к��де — это признак плохого кода, на самом деле комментарии могут быть чрезвычайно полезными. Они должны использоваться, чтобы объяснить сложные или нестандартные участки кода, особенно если решение является временным или связано с определенными ограничениями. Но комментарии не должны быть заменой для плохо написанного кода. Вместо комментариев лучше улучшить само имя переменной или функции.

Не забывайте и о документации! Это касается как API, так и внутренних компонентов приложения. Хорошая документация значительно упрощает поддержку кода и улучшает взаимодействие с коллегами. Особенно это важно в процессе создания сайтов или других проектов, где несколько человек работают над одной частью системы.

3. Модульность и повторное использование кода

Одной из важнейших практик является модульность. Создание независимых, переиспользуемых компонентов — это путь к упрощению разработки и поддержке кода. Используйте паттерны проектирования, такие как MVC (Model-View-Controller) или MVVM (Model-View-ViewModel), чтобы разделить логику, представление и управление состоянием.

Когда вы пишете код, старайтесь избегать дублирования. Повторение кода не только делает приложение менее эффективным, но и усложняет его поддержку. Чем меньше дублирования, тем проще тестировать и обновлять систему.

4. Тестирование и автоматизация

Тестирование — это обязательная часть процесса разработки. Написание юнит-тестов позволяет убедиться, что ваш код работает как задумано, и снижает количество ошибок в будущем. Важно автоматизировать тестирование, чтобы оно проводилось при каждом изменении в коде. Также стоит внедрить интеграционные тесты, чтобы проверять, как компоненты приложения взаимодействуют друг с другом.

Автоматизация также помогает при создании сайтов — с помощью CI/CD (непрерывной интеграции и непрерывного развертывания) можно быстро и безопасно обновлять веб-приложения. Это ускоряет процесс разработки и минимизирует риск ошибок.

5. Принципы SOLID

SOLID — это набор пяти принципов объектно-ориентированного программирования, которые помогают создать чистый и гибкий код. Они включают:

S — Single Responsibility Principle (Принцип единственной ответственности)

O — Open/Closed Principle (Принцип открытости/закрытости)

L — Liskov Substitution Principle (Принцип подстановки Лискова)

I — Interface Segregation Principle (Принцип разделения интерфейсов)

D — Dependency Inversion Principle (Принцип инверсии зависимостей)

Следование этим принципам помогает писать код, который легко поддерживать и расширять в будущем.

6. Контроль версий

Системы контроля версий, такие как Git, являются неотъемлемой частью разработки. Они позволяют отслеживать изменения, работать в команде и вернуться к предыдущим версиям кода в случае ошибки. Хорошая практика — регулярно коммитить изменения и использовать осмысленные сообщения к коммитам, чтобы другим было понятно, что было изменено.

Чистый и поддерживаемый код — это не просто красивый код, это код, который легко читать, тестировать и обновлять. Писать его непросто, особенно в условиях стартапа, где требуется быстрая разработка. Но следуя лучшим практикам — таким как модульность, использование комментариев, тестирование и принципы SOLID — вы сможете создать не только функциональный, но и долговечный продукт. Эти подходы применимы не только для мобильных приложений, но и для создания сайтов, где масштабируемость и поддерживаемость играют важнейшую роль в долгосрочной перспективе.

[daniiltkachev]

Mastering SOLID principles in PHP: Building robust and maintainable code

Explore the SOLID principles in PHP with practical examples, learn how they enhance code maintainability, and reduce technical debt in your applications. Discover how SOLID principles can transform your PHP code into a robust, scalable, and maintainable system with practical examples and actionable insights. Introduction to SOLID Principles The SOLID principles are a set of design guidelines that help developers create software that is easy to maintain, extend, and understand. These principles are particularly important in PHP development, where applications often grow in complexity over time. By adhering to SOLID, you can ensure your codebase remains clean and manageable. Single Responsibility Principle (SRP) The Single Responsibility Principle states that a class should have only one reason to change, meaning it should have only one job or responsibility. This principle helps in reducing the complexity of the code and makes it easier to test and maintain. class User { public function __construct(private string $name, private string $email) {} public function getName(): string { return $this->name; } public function getEmail(): string { return $this->email; } } class UserPrinter { public function print(User $user): void { echo $user->getName() . ' - ' . $user->getEmail(); } } In this example, the User class is responsible only for managing user data, while the UserPrinter class handles the printing logic. This separation adheres to SRP. Open/Closed Principle (OCP) The Open/Closed Principle suggests that software entities should be open for extension but closed for modification. This means you should be able to add new functionality without changing existing code. interface Shape { public function area(): float; } class Rectangle implements Shape { public function __construct(private float $width, private float $height) {} public function area(): float { return $this->width * $this->height; } } class Circle implements Shape { public function __construct(private float $radius) {} public function area(): float { return pi() * pow($this->radius, 2); } } Here, the Shape interface allows for the addition of new shapes without modifying the existing code, adhering to OCP. Liskov Substitution Principle (LSP) The Liskov Substitution Principle states that objects of a superclass should be replaceable with objects of a subclass without affecting the correctness of the program. This ensures that a subclass can stand in for its superclass without causing errors. class Bird { public function fly(): void { echo 'Flying'; } } class Sparrow extends Bird { public function fly(): void { echo 'Sparrow flying'; } } class Ostrich extends Bird { public function fly(): void { throw new Exception('Cannot fly'); } } In this example, the Ostrich class violates LSP because it cannot fly, unlike its superclass Bird. To adhere to LSP, we should reconsider the inheritance hierarchy. Interface Segregation Principle (ISP) The Interface Segregation Principle advocates for creating small, specific interfaces rather than large, general-purpose ones. This ensures that implementing classes only need to be concerned with the methods that are relevant to them. interface Printer { public function print(): void; } interface Scanner { public function scan(): void; } class AllInOnePrinter implements Printer, Scanner { public function print(): void { echo 'Printing'; } public function scan(): void { echo 'Scanning'; } } class SimplePrinter implements Printer { public function print(): void { echo 'Printing'; } } Here, the Printer and Scanner interfaces are segregated, allowing classes to implement only the methods they need. Dependency Inversion Principle (DIP) The Dependency Inversion Principle states that high-level modules should not depend on low-level modules. Both should depend on abstractions. This principle promotes the use of interfaces or abstract classes to decouple the system's components. interface Database { public function save($data): void; } class MySQLDatabase implements Database { public function save($data): void { echo 'Saving data to MySQL database'; } } class UserService { public function __construct(private Database $database) {} public function createUser($userData): void { $this->database->save($userData); } } In this example, the UserService depends on the Database interface, not on a specific database implementation, adhering to DIP. Conclusion By mastering the SOLID principles, PHP developers can create code that is not only robust and scalable but also easy to maintain and extend. These principles provide a solid foundation for building high-quality software that stands the test of time. Read the full article

[talonabraxas]

Veil upon Veil you hide The well-spring of the Infinite, The blue that delights, Pierces the heart, And produces a sapphire jewel.

Celestial Deity Talon Abraxas

"The light of the sun is the source of the colour we see reflected in the world. It begins in gamma rays whose wavelengths are a million times too short to see. By a process of absorption and re-emission throughout the sun's body, these spread out into longer wavelengths which travel through space and are further altered by interaction with the atmosphere. If there are no dusts or gases in the heavens, the sky appears black, as it does ten miles out from the earth's surface where the atmosphere thins out almost to the vanishing point." The old man adjusted himself in the chair and continued: "The colour of the sky, child, is closely associated with the way light, falling on matter, is scattered in all directions. The amount of scattered light is greater for shorter blue wavelengths than for longer red ones." Here the learned mariner became more technical and spoke slowly, using his hands to explain. "The intensity of scattered light is inversely proportional to the fourth power of the wavelength. Because of this, blue light loses more energy than red and its scattering is dependent upon low atmospheric content. In the atmosphere of the earth, molecules of gases scatter the blue waves in all directions while the red waves are absorbed, causing the sky to appear blue. The more rarefied the air, the greater the scattering of these short waves and the deeper the colour of blue. But when there is considerable dust or moisture in the air, the layers of particles scatter the longer red waves and cause the sky to become whiter. The red and blue light mixes to produce the whitened sky so common in higher latitudes where moisture particles hang in the air. So the dust rising in a hot, dry clime bleaches out the heavens until a heavy rain settles the earth and leaves behind it a deep saturated blue. Men long for that blue, child. They always dream of travelling south into the azure intensity that has inspired poets and painters for countless years. So thus they gaze out over the horizon as you do, trying to penetrate its vastness."

“Blue color is everlastingly appointed by the deity to be a source of delight.” — John Ruskin

Appointed by the Deity, it is the abode of the gods, their intrinsic attribute and celestial surrounding. It is the colour of the Queen of Heaven and the feminine principle of the Great Deep. It veils the impenetrable void of chaos and yet recedes into its folded mystery. It is the colour of the cloak of Hera and Zeus and clings to Diana's fleet, forested shape. It is reflected in the blue robes once worn by priests at the grave and by the Levites who called their garb the livery of heaven. 'The Blue' is a synonym for heaven and all that is divine. In the darkened depths of its expanse lies Nature's solitude, wrapped in a cold noumenal glow whose purity is incomparable. By its grace, the sea takes on its colour and draws the ocean of space into the world, but the purity of 'the Blue' remains aloft to be viewed from mountain tops on perfectly clear and blessed days.

[codezup]

Build Scalable Android Apps with Clean Architecture: Best Practices

1. Introduction What is Clean Architecture? Clean Architecture is a software design approach that separates an application into distinct layers, each with specific responsibilities. It ensures scalability, testability, and maintainability by adhering to principles like separation of concerns and dependency inversion. Importance In Android app development, Clean Architecture is crucial for…

[jcmarchi]

Implementing SOLID Principles in Android Development

New Post has been published on https://thedigitalinsider.com/implementing-solid-principles-in-android-development/

Implementing SOLID Principles in Android Development

Writing software is an act of creation, and Android development is no exception. It’s about more than just making something work. It’s about designing applications that can grow, adapt, and remain manageable over time.

As an Android developer who has faced countless architectural challenges, I’ve discovered that adhering to the SOLID principles can transform even the most tangled codebases into clean systems. These are not abstract principles, but result-oriented and reproducible ways to write robust, scalable, and maintainable code.

This article will provide insight into how SOLID principles can be applied to Android development through real-world examples, practical techniques, and experience from the Meta WhatsApp team.

The SOLID principles, proposed by Robert C. Martin, are five design principles for object-oriented programming that guarantee clean and efficient software architecture.

Single Responsibility Principle (SRP): A class should have one and only one reason to change.

Open/Closed Principle (OCP): Software entities should be open for extension but closed for modification.

Liskov Substitution Principle (LSP): Subtypes must be substitutable for their base types.

Interface Segregation Principle (ISP): Interfaces should be client-specific and not force the implementation of unused methods.

Dependency Inversion Principle (DIP): High-level modules should depend on abstractions, not on low-level modules.

By integrating these principles into Android development, we can create applications that are easier to scale, test, and maintain.

Single Responsibility Principle is the foundation of writing maintainable code. It states that each class must have a single concern it takes responsibility for. A common anti-pattern is considering Activities or Fragments to be some “God classes” that handle responsibilities starting from UI rendering, then data fetching, error handling, etc. This approach makes a test and maintenance nightmare.

With the SRP, separate different concerns into different components: for example, in an app for news, create or read news.

class NewsRepository fun fetchNews(): List // Handles data fetching logic class NewsViewModel(private val newsRepository: NewsRepository) fun loadNews(): LiveData<List> // Manages UI state and data flow class NewsActivity : AppCompatActivity() // Handles only UI rendering

Every class has only one responsibility; hence, it’s easy to test and modify without having side effects.

In modern Android development, SRP is mostly implemented along with the recommended architecture using Jetpack. For example, logic related to data manipulation logic might reside inside ViewModel, while the Activities or Fragments should just care about the UI and interactions. Data fetching might be delegated to some separate Repository, either from local databases like Room or network layers such as Retrofit. This reduces the risk of UI classes bloat, since each component gets only one responsibility. Simultaneously, your code will be much easier to test and support.

The Open/Closed Principle declares that a class should be opened for extension but not for modification. It is more reasonable for Android applications since they constantly upgrade and add new features.

The best example of how to use the OCP principle in Android applications is interfaces and abstract classes. For example:

interface PaymentMethod fun processPayment(amount: Double) class CreditCardPayment : PaymentMethod override fun processPayment(amount: Double) // Implementation for credit card payments class PayPalPayment : PaymentMethod override fun processPayment(amount: Double) // Implementation for PayPal payments

Adding new payment methods does not require changes to existing classes; it requires creating new classes. This is where the system becomes flexible and can be scaled.

In applications created for Android devices, the Open/Closed Principle is pretty useful when it comes to feature toggles and configurations taken dynamically. For example, in case your app has an AnalyticsTracker base interface that reports events to different analytics services, Firebase and Mixpanel and custom internal trackers, every new service can be added as a separate class without changes to the existing code. This keeps your analytics module open for extension-you can add new trackers-but closed for modification: you don’t rewrite existing classes every time you add a new service.

The Liskov Substitution Principle states that subclasses should be substitutable for their base classes, and the application’s behavior must not change. In Android, this principle is fundamental to designing reusable and predictable components.

For example, a drawing app:

abstract class Shape abstract fun calculateArea(): Double class Rectangle(private val width: Double, private val height: Double) : Shape() override fun calculateArea() = width * height class Circle(private val radius: Double) : Shape() override fun calculateArea() = Math.PI * radius * radius

Both Rectangle and Circle can be replaced by any other one interchangeably without the system failure, which means that the system is flexible and follows LSP.

Consider Android’s RecyclerView.Adapter subclasses. Each subclass of the adapter extends from RecyclerView.Adapter<VH> and overrides core functions like onCreateViewHolder, onBindViewHolder, and getItemCount. The RecyclerView can use any subclass interchangeably as long as those methods are implemented correctly and not break the functionality of your app. Here, the LSP is maintained, and your RecyclerView can be flexible to substitute any adapter subclass at will.

In larger applications, it is common to define interfaces with too much responsibility, especially around networking or data storage. Instead, break them into smaller, more targeted interfaces. For example, an ApiAuth interface responsible for user authentication endpoints should be different from an ApiPosts interface responsible for blog posts or social feed endpoints. This separation will prevent clients that need only the post-related methods from being forced to depend on and implement authentication calls, hence keeping your code, as well as the test coverage, leaner.

Interface Segregation Principle means that instead of having big interfaces, several smaller, focused ones should be used. The principle prevents situations where classes implement unnecessary methods.

For example, rather than having one big interface representing users’ actions, consider kotlin code:

interface Authentication fun login() fun logout() interface ProfileManagement fun updateProfile() fun deleteAccount()

Classes that implement these interfaces can focus only on the functionality they require, thus cleaning up the code and making it more maintainable.

The Dependency Inversion Principle promotes decoupling by ensuring high-level modules depend on abstractions rather than concrete implementations. This principle perfectly aligns with Android’s modern development practices, especially with dependency injection frameworks like Dagger and Hilt.

For example:

class UserRepository @Inject constructor(private val apiService: ApiService) fun fetchUserData() // Fetches user data from an abstraction

Here, UserRepository depends on the abstraction ApiService, making it flexible and testable. This approach allows us to replace the implementation, such as using a mock service during testing.

Frameworks such as Hilt, Dagger, and Koin facilitate dependency injection by providing a way to supply dependencies to Android components, eliminating the need to instantiate them directly . In a repository, for instance, instead of instantiating a Retrofit implementation, you will inject an abstraction-for example, an ApiService interface. That way, you could easily switch the network implementation-for instance, an in-memory mock service for local testing-and would not need to change anything in your repository code. In real-life applications, you can find that classes are annotated with @Inject or @Provides to provide these abstractions, hence making your app modular and test-friendly.

Adopting SOLID principles in Android development yields tangible benefits:

Improved Testability: Focused classes and interfaces make it easier to write unit tests.

Enhanced Maintainability: Clear separation of concerns simplifies debugging and updates.

Scalability: Modular designs enable seamless feature additions.

Collaboration: Well-structured code facilitates teamwork and reduces onboarding time for new developers.

Performance Optimization: Lean, efficient architectures minimize unnecessary processing and memory usage.

In feature-rich applications, such as e-commerce or social networking apps, the application of the SOLID principles can greatly reduce the risk of regressions every time a new feature or service is added. For example, if a new requirement requires an in-app purchase flow, you can introduce a separate module that will implement the required interfaces (Payment, Analytics) without touching the existing modules. This kind of modular approach, driven by SOLID, allows your Android app to quickly adapt to market demands and keeps the codebase from turning into spaghetti over time.

While working on a large project which requires many developers to collaborate,, it is highly recommended  to keep a complex codebase with SOLID principles. For example, separating data fetching, business logic, and UI handling in the chat module helped reduce the chance of regressions while scaling the code with new features. Likewise, the application of DIP was crucial to abstract network operations, hence being able to change with almost no disruption between network clients.

More than a theoretical guide, the principles of SOLID are actually the practical philosophy for creating resilient, adaptable, and maintainable software. In the fast-moving world of Android development, with requirements changing nearly as often as technologies are, adherence to these principles provides a firm ground on which success may be founded.

Good code is not just about making something work—it’s about creating a system that can continue to work and grow with evolving needs. By embracing SOLID principles, you’ll not only write better code but also build applications that are a joy to develop, scale, and maintain.

[masongrizchel]

Blackbody Radiation and Its Role in Astrophysics

Light is a storyteller, revealing the secrets of the universe. From the glow of distant stars to the cosmic background radiation left over from the Big Bang, the study of black body radiation is fundamental to understanding astrophysics. It helps astronomers determine the temperature, composition, and life cycles of celestial objects, making it one of the most powerful concepts in modern astrophysical research.

What is Black Body Radiation?

A black body is an idealized object that absorbs all incident electromagnetic radiation, regardless of wavelength and emits radiation solely based on its temperature. This emitted radiation follows a characteristic spectrum known as black body radiation, which depends only on temperature and is described by Planck’s Law:

This equation describes how an object radiates energy at different wavelengths, forming a characteristic black body curve that peaks at a specific wavelength determined by its temperature.

Key Properties of Black Body Radiation

Wien’s Displacement Law: This law states that the peak wavelength of black body radiation shifts inversely with temperature. Hotter objects emit more light at shorter (bluer) wavelengths, while cooler objects emit at longer (redder) wavelengths.

Stefan-Boltzmann Law: This law states that the total energy emitted per unit area of a black body is proportional to the fourth power of its temperature. This explains why hotter stars shine much more intensely than cooler ones.

Black Body Radiation in Astrophysics

1. Understanding Stellar Spectra

Stars closely approximate black bodies, and their color and spectrum provide direct insights into their temperature. Using Wien’s Law, astronomers can estimate a star’s surface temperature simply by analyzing its peak emission wavelength.

Hot stars (e.g., blue-white stars like Rigel) have temperatures around 10,000–25,000 K and emit most of their radiation in the ultraviolet and blue regions.

Cooler stars (e.g., red dwarfs like Proxima Centauri) have temperatures around 3,000 K and emit primarily in the red and infrared.

By comparing a star’s observed spectrum with theoretical black body curves, astronomers classify stars into spectral types (O, B, A, F, G, K, M) and determine their physical properties.

2. Cosmic Microwave Background (CMB) Radiation

The CMB is the faint afterglow of the Big Bang and is considered one of the best examples of black body radiation in the universe. Its spectrum perfectly matches that of a black body at 2.73 K, confirming that it originated from an early, hot phase of the universe.

The discovery of the CMB by Arno Penzias and Robert Wilson in 1965 provided strong evidence for the Big Bang theory, revolutionizing our understanding of cosmology.

3. White Dwarfs and Neutron Stars

White dwarfs are the remnants of Sun-like stars, while neutron stars are even denser stellar remnants. Both radiate heat as they slowly cool over billions of years. Their cooling behavior follows black body principles, allowing astronomers to estimate their ages and predict their long-term evolution.

4. Exoplanet Studies

Infrared telescopes use black body radiation principles to study exoplanets (planets orbiting other stars). By measuring their thermal emission, astronomers can determine surface temperatures and even infer atmospheric compositions.

5. Accretion Disks Around Black Holes

The superheated gas spiraling into black holes emits radiation that approximates a multi-temperature black body spectrum. The peak wavelength of this emission depends on the mass and spin of the black hole, offering indirect ways to study these enigmatic objects.

Did you know?

The Sun’s black body temperature is around 5,778 K, peaking in the visible light spectrum, which is why our eyes evolved to be most sensitive to this range.

The hottest stars, known as Wolf-Rayet stars, can exceed 200,000 K, emitting primarily in the ultraviolet.

Black body radiation also plays a role in climate science, as Earth's atmosphere absorbs and re-emits infrared radiation, influencing global temperatures.

Conclusion

Black body radiation is a cornerstone of astrophysics, helping us decode the light from stars, galaxies, and the early universe. Whether studying the glow of a distant quasar, the cooling of a white dwarf, or the relic radiation of the Big Bang, this fundamental concept allows astronomers to piece together the grand story of the cosmos.

The next time you see the warm glow of a sunset or the twinkle of a star, remember—you’re witnessing the principles of black body radiation in action, a phenomenon that connects everything from a simple candle flame to the most distant reaches of the universe.