The document describes refactoring an existing video rental program to make it easier to add a new requirement of generating HTML statements. The program's structure is not well-suited for adding new features. To address this, the author extracts a method from the long statement() method to calculate rental amounts, improving the design and making it easier to add the new HTML feature. This is an example of how refactoring can restructure code to enable adding new capabilities without rewriting existing code.
The document discusses code refactoring and code smells. It provides an overview of code refactoring techniques such as extract class, extract method, rename method, substitute algorithm, decompose conditional, consolidate conditional expression, consolidate duplicate conditional fragments, introduce parameter object, inline temporary variable, and replace magic number with symbolic constant. It also describes common code smells like duplicated code, large class, long method, long parameter list, lazy class, switch statements, undescriptive names, temporary fields, message chains, and comments. The document emphasizes that refactoring is important to improve code quality and reduce complexity, and that developers should refactor frequently to avoid code smells.
The Django Book chapter 4 templates (supplement)Vincent Chien
The document discusses Django's template inheritance system. It introduces a base template that defines common elements like the page header and footer. This base template uses block tags to denote sections that child templates can override. Two child templates are shown that extend the base template and override its title and content blocks to customize each page while maintaining a common layout. Template inheritance allows avoiding redundancy and making site-wide changes by modifying only the base template.
This document discusses lambda expressions and functional interfaces in Java 8. It begins by providing examples of lambda expressions that act as anonymous implementations of interfaces with single abstract methods (SAM interfaces). It then explains various functional interfaces like Function, BiFunction, Consumer, Supplier, and Predicate that can be used with lambda expressions. The document emphasizes how lambda expressions allow removing unnecessary elements to focus on the essential parameters and body of an operation.
This will help you to identify the scope to refactor your code. Compiled from Refactoring: Improving the Design of Existing Code by Martin Fowler et al.
Refactoring of code for more readable, scalable modules based on The book titled "Refactoring - Improving the Design of Existing Code" written by Martin Fowler
This document discusses refactoring code to improve its design without changing external behavior. It notes that refactoring involves making small, incremental changes rather than large "big bang" refactorings. Code smells that may indicate a need for refactoring include duplication, long methods, complex conditional logic, speculative code, and overuse of comments. Techniques discussed include extracting methods, removing duplication, using meaningful names, removing temporary variables, and applying polymorphism. The document emphasizes that refactoring is an investment that makes future changes easier and helps avoid bugs, and encourages learning from other programming communities.
Creational Pattern of the design pattern.
Introducing 6 type patterns and also including the pros and cons. It's easy to understand what's kind of scenario it should be used.
The document discusses code refactoring and code smells. It provides an overview of code refactoring techniques such as extract class, extract method, rename method, substitute algorithm, decompose conditional, consolidate conditional expression, consolidate duplicate conditional fragments, introduce parameter object, inline temporary variable, and replace magic number with symbolic constant. It also describes common code smells like duplicated code, large class, long method, long parameter list, lazy class, switch statements, undescriptive names, temporary fields, message chains, and comments. The document emphasizes that refactoring is important to improve code quality and reduce complexity, and that developers should refactor frequently to avoid code smells.
The Django Book chapter 4 templates (supplement)Vincent Chien
The document discusses Django's template inheritance system. It introduces a base template that defines common elements like the page header and footer. This base template uses block tags to denote sections that child templates can override. Two child templates are shown that extend the base template and override its title and content blocks to customize each page while maintaining a common layout. Template inheritance allows avoiding redundancy and making site-wide changes by modifying only the base template.
This document discusses lambda expressions and functional interfaces in Java 8. It begins by providing examples of lambda expressions that act as anonymous implementations of interfaces with single abstract methods (SAM interfaces). It then explains various functional interfaces like Function, BiFunction, Consumer, Supplier, and Predicate that can be used with lambda expressions. The document emphasizes how lambda expressions allow removing unnecessary elements to focus on the essential parameters and body of an operation.
This will help you to identify the scope to refactor your code. Compiled from Refactoring: Improving the Design of Existing Code by Martin Fowler et al.
Refactoring of code for more readable, scalable modules based on The book titled "Refactoring - Improving the Design of Existing Code" written by Martin Fowler
This document discusses refactoring code to improve its design without changing external behavior. It notes that refactoring involves making small, incremental changes rather than large "big bang" refactorings. Code smells that may indicate a need for refactoring include duplication, long methods, complex conditional logic, speculative code, and overuse of comments. Techniques discussed include extracting methods, removing duplication, using meaningful names, removing temporary variables, and applying polymorphism. The document emphasizes that refactoring is an investment that makes future changes easier and helps avoid bugs, and encourages learning from other programming communities.
Creational Pattern of the design pattern.
Introducing 6 type patterns and also including the pros and cons. It's easy to understand what's kind of scenario it should be used.
This document summarizes Spring features for building loosely coupled, maintainable applications. It discusses how Spring promotes loose coupling through dependency injection and application events. It also describes how to implement workflows with jBPM and manage transactions declaratively in Spring.
The document provides information about C++ aptitude and object-oriented programming (OOP) concepts. It contains sample C++ code snippets and questions with explanations to test understanding of topics like classes, inheritance, polymorphism, operator overloading, templates, and more.
Design pattern part 2 - structural patternJieyi Wu
This is first part: https://www.slideshare.net/JieyiWu1/design-pattern-part-1-81195876
Structural Pattern is introducing 7 type patterns and also including the pros and cons to you.
Behavioral Pattern of the design pattern.
Introducing 6 type patterns and also including the pros and cons. It's easy to understand what's kind of scenario it should be used.
This document outlines various refactoring techniques including self-encapsulating fields, replacing data values with objects, changing values to references, changing references to values, replacing arrays with objects, duplicating observed data, changing unidirectional associations to bidirectional, and changing bidirectional associations to unidirectional. Each technique is explained with examples to illustrate how it can be implemented in code.
Object Oriented Solved Practice Programs C++ ExamsMuhammadTalha436
The question asks to create classes to represent publications, books, and tapes. The Publication class has title and price attributes. The Book class inherits from Publication and adds a noOfPages attribute. The Tape class inherits from Publication and adds a playingTime attribute.
The document discusses refactoring techniques to replace type codes with other object-oriented constructs. It describes replacing magic numbers with symbolic constants to make code more readable. It also covers replacing type codes with classes, subclasses, or state/strategy objects to encapsulate behavior associated with different types and allow polymorphism. This improves extensibility and maintains type safety compared to using raw integer type codes.
This document discusses JavaScript functions. It covers function definitions, invocation patterns, the this keyword, and function methods like call, apply, and bind. Function definitions can be declared using the function keyword or assigned anonymously. Functions are first-class citizens that can be passed around and returned. Invocation patterns include direct invocation, method invocation, constructor invocation, and reflective invocation using call and apply. The this keyword is determined by the invocation pattern and bind can be used to set the this value.
The document discusses functional JavaScript programming. It introduces functional concepts like anonymous functions, binding functions to contexts, and enumerable functions. It provides examples of how to write functional code using these concepts like mapping over arrays with anonymous functions and filtering arrays. It also discusses structuring applications and provides an example code snippet for converting HTML elements.
How and why I turned my old Java projects into a first-class serverless compo...Mario Fusco
Mario Fusco discusses turning old Java rule engine projects into serverless components by refactoring them to run natively on GraalVM and integrate with Quarkus. He describes the limitations of ahead-of-time compilation with GraalVM, such as lack of dynamic classloading. He details refactoring Drools to use an executable model and removing dependencies on dynamic class definition. This allows Drools to natively compile on GraalVM. He also discusses integrating the refactored Drools with Quarkus.
Effective Java with Groovy - How Language Influences Adoption of Good PracticesNaresha K
This document summarizes key points from a presentation about how the Groovy programming language helps developers adopt good practices outlined in Effective Java. It discusses how some Effective Java items like avoiding nulls and enforcing immutability are built into Groovy. AST transformations further reduce work by implementing patterns like the singleton pattern. While Effective Java provides good guidelines, direct implementations may not always apply to Groovy - the language aims to reduce friction to writing good code. Overall, programming languages can help developers implement best practices through built-in functionality and transformations.
Since these presentations were spare time hobby - I've decided to share them :)
Hopefully someone will find them useful.
This part continues 1. part with more design patterns like Command, State, NullObject.
(download for flawless quality) A brief introduction to unison, the exciting and innovative new functional programming language.
Wholly based on a talk by Paul Chiusano.
A recursive function is a function that calls itself. A recursive function is used for repeating code. If the state of the function does not change, and it has no preset exit condition that is reached, a recursive call can turn into an infinite loop.
Functions in JavaScript can be named or anonymous. Nested functions can access variables of parent functions but not vice versa. Functions can be stored in variables, passed as parameters, and used in expressions. Functions are passed by value, except for objects which are passed by reference. Functions can be invoked as functions, methods, or constructors and indirectly through call and apply. Optional parameters should be passed last and can be handled with undefined checks. Functions create local scopes for variables except global variables. Functions can be used to organize code into namespaces. Higher order functions take and return other functions.
This document discusses various refactoring techniques for simplifying conditional expressions and logic in code. It provides examples of refactoring techniques like decomposing conditional expressions, consolidating duplicate conditional fragments, removing control flags, replacing nested conditionals with guard clauses, replacing conditionals with polymorphism, introducing null objects, and introducing assertions. The goal of these refactoring techniques is to simplify complex conditional logic and make the code easier to read, understand and maintain.
Currying and Partial Function Application (PFA)Dhaval Dalal
We look at Currying and Partial Function Application (PFA) in Functional Programming. Languages like Clojure don't have currying, but PFA, where has Haskell currying and not PFA, whereas Scala has both, Groovy wants you to call methods like curry() and rcurry(). In OO paradigm, we use DI (dependency Injection) and we will see how this is automatically subsumed using Currying and PFA.
This document provides an overview of setting up MySQL replication between a master database server and one or more slave servers. It discusses creating a user for replication, configuring the master with binary logging and a server ID, configuring slaves with unique server IDs, obtaining the replication information from the master, and using mysqldump or raw data files to initialize slaves with data from the master. It also covers starting new replication environments and adding additional slaves.
The document discusses refactoring, which is improving the internal structure of code without changing its external behavior or functionality. It covers the goals of refactoring, provides examples of refactoring code, and discusses principles and techniques for refactoring safely and incrementally through testing. Reasons to refactor include improving software design over time, reducing bugs, and enabling faster development by keeping code easy to understand and modify.
This document summarizes Spring features for building loosely coupled, maintainable applications. It discusses how Spring promotes loose coupling through dependency injection and application events. It also describes how to implement workflows with jBPM and manage transactions declaratively in Spring.
The document provides information about C++ aptitude and object-oriented programming (OOP) concepts. It contains sample C++ code snippets and questions with explanations to test understanding of topics like classes, inheritance, polymorphism, operator overloading, templates, and more.
Design pattern part 2 - structural patternJieyi Wu
This is first part: https://www.slideshare.net/JieyiWu1/design-pattern-part-1-81195876
Structural Pattern is introducing 7 type patterns and also including the pros and cons to you.
Behavioral Pattern of the design pattern.
Introducing 6 type patterns and also including the pros and cons. It's easy to understand what's kind of scenario it should be used.
This document outlines various refactoring techniques including self-encapsulating fields, replacing data values with objects, changing values to references, changing references to values, replacing arrays with objects, duplicating observed data, changing unidirectional associations to bidirectional, and changing bidirectional associations to unidirectional. Each technique is explained with examples to illustrate how it can be implemented in code.
Object Oriented Solved Practice Programs C++ ExamsMuhammadTalha436
The question asks to create classes to represent publications, books, and tapes. The Publication class has title and price attributes. The Book class inherits from Publication and adds a noOfPages attribute. The Tape class inherits from Publication and adds a playingTime attribute.
The document discusses refactoring techniques to replace type codes with other object-oriented constructs. It describes replacing magic numbers with symbolic constants to make code more readable. It also covers replacing type codes with classes, subclasses, or state/strategy objects to encapsulate behavior associated with different types and allow polymorphism. This improves extensibility and maintains type safety compared to using raw integer type codes.
This document discusses JavaScript functions. It covers function definitions, invocation patterns, the this keyword, and function methods like call, apply, and bind. Function definitions can be declared using the function keyword or assigned anonymously. Functions are first-class citizens that can be passed around and returned. Invocation patterns include direct invocation, method invocation, constructor invocation, and reflective invocation using call and apply. The this keyword is determined by the invocation pattern and bind can be used to set the this value.
The document discusses functional JavaScript programming. It introduces functional concepts like anonymous functions, binding functions to contexts, and enumerable functions. It provides examples of how to write functional code using these concepts like mapping over arrays with anonymous functions and filtering arrays. It also discusses structuring applications and provides an example code snippet for converting HTML elements.
How and why I turned my old Java projects into a first-class serverless compo...Mario Fusco
Mario Fusco discusses turning old Java rule engine projects into serverless components by refactoring them to run natively on GraalVM and integrate with Quarkus. He describes the limitations of ahead-of-time compilation with GraalVM, such as lack of dynamic classloading. He details refactoring Drools to use an executable model and removing dependencies on dynamic class definition. This allows Drools to natively compile on GraalVM. He also discusses integrating the refactored Drools with Quarkus.
Effective Java with Groovy - How Language Influences Adoption of Good PracticesNaresha K
This document summarizes key points from a presentation about how the Groovy programming language helps developers adopt good practices outlined in Effective Java. It discusses how some Effective Java items like avoiding nulls and enforcing immutability are built into Groovy. AST transformations further reduce work by implementing patterns like the singleton pattern. While Effective Java provides good guidelines, direct implementations may not always apply to Groovy - the language aims to reduce friction to writing good code. Overall, programming languages can help developers implement best practices through built-in functionality and transformations.
Since these presentations were spare time hobby - I've decided to share them :)
Hopefully someone will find them useful.
This part continues 1. part with more design patterns like Command, State, NullObject.
(download for flawless quality) A brief introduction to unison, the exciting and innovative new functional programming language.
Wholly based on a talk by Paul Chiusano.
A recursive function is a function that calls itself. A recursive function is used for repeating code. If the state of the function does not change, and it has no preset exit condition that is reached, a recursive call can turn into an infinite loop.
Functions in JavaScript can be named or anonymous. Nested functions can access variables of parent functions but not vice versa. Functions can be stored in variables, passed as parameters, and used in expressions. Functions are passed by value, except for objects which are passed by reference. Functions can be invoked as functions, methods, or constructors and indirectly through call and apply. Optional parameters should be passed last and can be handled with undefined checks. Functions create local scopes for variables except global variables. Functions can be used to organize code into namespaces. Higher order functions take and return other functions.
This document discusses various refactoring techniques for simplifying conditional expressions and logic in code. It provides examples of refactoring techniques like decomposing conditional expressions, consolidating duplicate conditional fragments, removing control flags, replacing nested conditionals with guard clauses, replacing conditionals with polymorphism, introducing null objects, and introducing assertions. The goal of these refactoring techniques is to simplify complex conditional logic and make the code easier to read, understand and maintain.
Currying and Partial Function Application (PFA)Dhaval Dalal
We look at Currying and Partial Function Application (PFA) in Functional Programming. Languages like Clojure don't have currying, but PFA, where has Haskell currying and not PFA, whereas Scala has both, Groovy wants you to call methods like curry() and rcurry(). In OO paradigm, we use DI (dependency Injection) and we will see how this is automatically subsumed using Currying and PFA.
This document provides an overview of setting up MySQL replication between a master database server and one or more slave servers. It discusses creating a user for replication, configuring the master with binary logging and a server ID, configuring slaves with unique server IDs, obtaining the replication information from the master, and using mysqldump or raw data files to initialize slaves with data from the master. It also covers starting new replication environments and adding additional slaves.
The document discusses refactoring, which is improving the internal structure of code without changing its external behavior or functionality. It covers the goals of refactoring, provides examples of refactoring code, and discusses principles and techniques for refactoring safely and incrementally through testing. Reasons to refactor include improving software design over time, reducing bugs, and enabling faster development by keeping code easy to understand and modify.
This document discusses high availability solutions for MySQL databases. It covers MySQL replication, MySQL Cluster, and DRBD. MySQL replication allows for one master and multiple slaves but has some limitations. MySQL Cluster provides automatic partitioning and failover between data nodes. DRBD can synchronize block-level replication between nodes for increased availability. The document provides an overview of each technology and their strengths for high availability use cases.
The document provides examples of refactoring code and writing unit tests. In the refactoring example, a team reviews and refactors Java code that calculates fees for investment accounts using techniques like Extract Method, Replace Magic Number with Symbolic Constant, and Introduce Explaining Variable. In the unit testing example, JUnit tests are constructed to verify the refactored code handles typical, boundary, and error cases. The tests validate expected behavior and failures.
This document summarizes steps taken to refactor code for calculating and printing a customer's video rental charges. The initial code was not well structured, with the statement() method doing too much. Through a series of small refactoring steps like extracting methods and moving methods to appropriate classes, the code was improved. Key steps included decomposing statement() into logical chunks, moving the amount calculation to the Rental class, and eliminating unnecessary variables. The end goal was to make the code easier to understand and modify.
How to build a react native app with the help of react native hooksKaty Slemon
How to build React Native application using React Hooks. Hire React Native developer to extract component logic into reusable functions without writing a class.
The document discusses refactoring tips provided by Martin Fowler. It defines refactoring as improving the internal structure of software without changing its external behavior. It provides examples of common refactoring techniques like extract method, inline method, move method, and consolidate conditional expressions. The goal of refactoring is to improve code quality by making software easier to understand and modify over time.
In depth overview of the Flex data binding code generation. Provides info on accomplish data binding through actionscript as well as limitations of the process.
The document discusses different types of variable scope in C programming:
1. Block scope - Variables declared within a code block using curly braces {} are only accessible within that block.
2. Function scope - Variables declared within a function are only accessible within that function.
3. Global scope - Variables declared outside of any block or function can be accessed from anywhere in the program file.
4. File scope - Variables can be declared with the static keyword to limit their scope to the current source code file. The static keyword also prevents local variables from being destroyed after the block or function ends.
This document summarizes enhancements to the .NET Framework 4, covering topics such as LINQ, ASP.NET, WCF, WPF, ADO.NET, C#, VB.NET, the Common Language Runtime, garbage collection, and exception handling. It also discusses parallel programming enhancements, the System.Device.Location API, in-process side-by-side assemblies, primary interop assemblies, and code contracts. The presentation provides demonstrations of key features.
This document discusses React component lifecycles and how React performs efficient re-renders. It explains the different lifecycle methods like componentWillMount, componentDidMount, etc. It then discusses how React batches state updates and only re-renders components when necessary using techniques like shouldComponentUpdate. It also explains React's reconciliation algorithm which intelligently updates the DOM by diffing virtual DOM trees in an efficient way when keys are provided. Overall the document provides an overview of key techniques React uses to optimize re-rendering for performance.
The document discusses refactoring code to improve its structure and readability without changing its external behavior. It defines refactoring as restructuring software to make it easier to understand and modify. The goals of refactoring are to reduce technical debt by improving code quality. Examples show refactoring an Android app by extracting methods, renaming variables for clarity, and converting the architecture to MVP pattern to separate concerns. Lessons recommend writing unit tests first and using metrics as a guide rather than mandate when refactoring.
Adding a modern twist to legacy web applicationsJeff Durta
Avoid misery of working with legacy code
We will see how you can add independent and isolated components to existing pages; pages that may be difficult to change
React and Flux allow you to make self-contained additions that handle their own data access/persistence
The document provides an overview of various design patterns including the Strategy Pattern, Template Method Pattern, Component Configuration Pattern, Reflection Pattern, Pipe and Filter Pattern, Factory Pattern, Observer Pattern, and Chain of Responsibility Pattern. It discusses the core principles and intents of each pattern, provides examples of how they can be implemented in code, and notes the relationships between different patterns.
Presentation on design pattern software project lll Uchiha Shahin
We have prepared a presentation on design pattern. Here are 7 types of design pattern we have presented.
1. Mediator Design
2. Iterator Pattern
3. Bridge Pattern
4. Decorator Pattern
5. Composite Pattern
6. Template Pattern
7. Singleton Pattern
Here is the link of Canva Slide to use as template----
https://www.canva.com/design/DAEmun8Sjks/NmH08MOYrAWSaTERNbe5LA/view?utm_content=DAEmun8Sjks&utm_campaign=designshare&utm_medium=link&utm_source=sharebutton&mode=preview
You can contact me in LinkedIn or any other social platform for more infromation.
Thank you.
This document discusses principles of clean code based on the book "Clean Code" by Robert C. Martin. It provides examples of good and bad practices for naming variables and functions, structuring functions, using comments, and other topics. Key points include using meaningful names, keeping functions small and focused on a single task, avoiding deeply nested code and long argument lists, commenting to explain intent rather than state the obvious, and other guidelines for writing clean, readable code.
The document introduces Test Driven Development (TDD), Continuous Integration (CI), Inversion of Control (IoC), and Aspect Oriented Programming (AOP). It discusses TDD principles and tools for writing tests first before code. CI aims to integrate code changes frequently to prevent integration problems. IoC and dependency injection improve software design by reducing coupling between components. AOP allows cross-cutting concerns like logging to be coded separately from the main program logic.
The document discusses the basics of the Eclipse debug platform, including an overview of key components like the standard debug model, launch framework, breakpoints, and variables view. It describes how these provide common abstractions and interfaces that debugger implementations can use to integrate with the platform and user interface. It also provides an example of implementing a debugger for a pushdown automaton language to demonstrate how this works.
The document provides an overview of the Eclipse debug platform and its main components. It describes the standard debug model, which includes common abstractions like processes, threads, stack frames and variables. It also covers the launch framework, which handles running and debugging code through launch configurations, delegates and modes. Custom debuggers integrate with these components by implementing interfaces and contributing extensions.
Vertical application partitioning allows a database system to scale to nearly unlimited levels by distributing application processing across all system resources. It involves splitting the database backend, application server, web server, and client display into separate tiers. Further, it involves partitioning entities like users across multiple database clusters based on attributes like user IDs, to distribute the load. This approach avoids bottlenecks and allows scaling simply by adding more database clusters as user numbers increase.
This document summarizes new replication features in MySQL versions 5.1, 6.0, and 5.4. Key features include row-based replication in 5.1, ignoring servers in circular replication in 6.0/5.4, replication heartbeat and slave position synchronization in 6.0/5.4, automatic relay log recovery in 6.0/5.4, and semi-synchronous replication as a pluggable architecture in 6.0/5.4. Ongoing projects previewed include multi-threaded replication slaves and time-delayed replication.
The document discusses various topics related to optimizing performance in MySQL databases, including:
1. Choosing optimal data types can improve performance by reducing storage size and simplifying queries. Smaller and simpler types are generally better.
2. Indexing is important for performance. The document discusses different index types like B-Tree indexes and their uses. Indexes should be chosen based on the types of queries.
3. Benchmarking and profiling are important to identify bottlenecks. Benchmarking tests overall performance while profiling identifies specific costly operations. The results can help optimize the database, queries, or hardware configuration.
This document discusses software refactoring and provides examples. It defines refactoring as improving the design of existing code without changing its observable behavior. Refactoring is important for software evolution as designs inevitably become outdated. Examples of refactoring techniques include extracting methods, using null objects, replacing switch statements with polymorphism, and inheritance. The document also discusses bad code smells and anti-patterns that refactoring can help address, such as long methods, large classes, duplicate code, and high coupling between classes.