In the tech industry, reusing code is a common technique for achieving high efficiency, especially on projects that utilize open source frameworks. The concept of code reuse is usually applied in two different ways:

• Reusing code that you’ve already written
• Reusing external code for your own project

To meet rising demand for smarter products and software, you’ll want to ensure that any code that you reuse is safe and high-quality, and that any libraries to be reused are secure and trustable.

Reusability can be applied across multiple platforms including app development, software development, embedded systems, and web development and is practiced in many languages. Code reuse basically a required practice in modern development environments to enable rapid development at low cost. You can also reuse different assets such as applications, components, objects, or functions.

Why it code reuse important?

Suppose a developer spends many weeks to write a chunk of code which enables socket communication. If the same functionality is required in another project, then an efficient dev would not waste time recreating the code and would instead take advantage of their previous block of code. This in turn speeds up the overall completion time.

Many organizations create a shared database of code components to get their work done quickly, with as many as 80 percent of code blocks already built and shared among team members.

Consistency in reusing code provides scalability and full control to devs for development. Pre-tested code reduces risk of failure because you embed the piece of code which is already used by people multiple times and is proven to work.

Code reuse classifications

The following are some common ways to identify and implement separate components of reusable code for speedy development, using less time and fewer resources:

Internal	In this type, the organization reuses its own components internally. This may involve copying existing code into new milestones. Code redundancy needs special attention in this type.
External	A third-party licensed component is integrated to cut down development costs. Teams must take time to initially analyze the best available options according to product requirements.
Planned	This approach assumes the usage of tactically designed building blocks of code that have been created to fulfill the future needs of an organization.
Opportunistic	In the beginning stages of a project, teams analyze the requirements and driving factors of the desired product and accordingly track down which existing components they can reuse.
Referenced	This type deals with the form and structure of code, in the sense that reused code has a reference and a specific version.

Using a prior version of a component as a beginning point for another version also falls into one of the code reuse types. Object-oriented and generic programming are main concerns for formal code reuse practices.

Ways to Reuse Code

Certain factors are critical when writing reusable code. Please note, however, that these attributes alone do not help unless they serve an overall strategy.

• Modularization is one approach for producing high-quality code. This method can be used to divide a software system into independent chunks that each perform a certain functionality. In this way, the code becomes more manageable. It eliminates the need to repetitively write code.
• Cohesion is the way two modules of a class or system work together to create a sense of purpose. Cohesive code becomes reusable across multiple projects and possesses the ability to adapt to different environments.
• Loosely coupled software modules use portable code that is not affected by external linkage. However, devs must manage a few links between functions and classes because zero coupling is also not a good option, so a balance must be struck.
• Making utility classes is one modern way to use them in multiple projects. You can add useful methods in these classes, such as basic functions of data formatting and sharing, validation constraints, image sharing, compression and image download, etc.
• Ensure flexibility in your code so that it can be used in future projects with minor alteration and serve the required purpose without crashing.
• Don’t write lines of code that are not needed, and follow the DRY principal of “Don’t repeat yourself.”
• Adhere to making one module perform one thing at a time. For example, a method for file compression must only take a file as input and return the compressed form as output. This technique will decouple this method from the rest of project so that you can reuse it efficiently.

Each approach has its own pros and cons, and choosing the appropriate method solely depends on your project needs and anticipated outcome.

There exist endless methodologies to reuse code without rewriting or copy/pasting from somewhere. A few are listed below:

Inheritance

Inheritance is extensively used in OOP paradigms. Developers reuse function overriding effortlessly to make various methods work differently for multiple objects.

Libraries

Dynamic linked libraries is another concept to recall here. DLL has its implication in .NET applications. If you have used NuGet package, then you must be aware of these libraries. Third-party libraries specifically designed to perform a unique function also facilitate code reuse.

Forking

Forking is a basic process in Git. People who use Git know that forking is using someone else’s code by altering it to fit your own needs and to distribute it further under your tag. This exercise is handy for open source projects, such as making modifications under the hood and creating a new framework.

Methods/Function Calls

In function calls, changes are made at one place and then reflected everywhere else where that function would be called. This allows you to modify code just once to satisfy a user’s demand.

There are many other methodologies to use under different paradigms, but I have stated only basic ones in this post to give you an idea about varying degrees of code reuse.

What makes it difficult to reuse code

On one hand, code reuse is the best practice to boost productivity, but on the other hand, it comes with some downsides and obstacles to deal with. In large organizations, it is critical to communicate guidance, requirement docs, and feedback to implement code reuse. Moreover, it is often worthwhile to create a “global repository” for archiving and file sharing between developers.

Operational Challenges: “More Time, More Resources”

Additional time and personnel resources are required to put effort into designing and testing the code for later use. Poor planning and underinvestment of time and resources make it impossible to achieve desired goals.

Technical Challenges: “Credibility, Security, Performance”

In order to be reused, code must be secure, reliable, efficient, fault-tolerant, and manageable. Each module has its own risk profile that requires constant attention from managers and team members.

Code Reuse in Practice

The production of a high-quality end product within a shorter development time is the main benefit of practicing code reuse. For large enterprises, it is compulsory to maintain documented data of every third-party component in use so that they do not lose track of it later. Reuse code from trusted sources and always remember to address any vulnerabilities before use to boost operational performance.

Suppose you are working on different Android projects that use the same classes, and, on making a certain change, you are prompted to do it three times. This is where code reusability creates an edge condition. To deal with similar kinds of situations, the best possible methods are:

Git Submodules

A submodule allows you to make a subdirectory for another Git repository. Shared code can be put in submodules to be used in multiple projects. However, this approach has a negative image because it carries major drawbacks. For example, it creates coupling between projects, thus making it difficult to handle cross-repository project. In addition, submodules are not updated automatically by pulling from their parent directory.

RAD Stack

Utilizing a modern, open source stack is a popular way to support all platforms and reuse common frontend components simultaneously. Being an open source framework, RAD stack (React Native and Django) contains a vast collection of open source libraries and cross-site scripting to protect your application against vulnerabilities. Stacks of RAD-scalable APIs allow users to access third-party services and also provide the option to add and remove services, thus building fast and future-proof apps.

Creating Your Own Libraries

Instead of using several small packages, a shared library is a suitable option. It contains the code to be reused in a warehouse image. One snag in using publicly shared libraries since is that it can create redundancy across multiple projects and require complicated dependency management.

Monorepos

Multi-package repositories permit keeping multiple packages in a single repository. Tool like Lerna help you to configure, unify, and publish multiple components from repo. Its disadvantages include extensive refactoring and management of dependency graphs.

Bit

This widely used and in-demand JS tool grants smooth code reuse by controlling unified code changes and a component dependency tree. Its workflow automatically defines and tracks shared components in all projects, displays their dependency graphs, and require no refactoring for reuse purposes. You can share your components on a remote server (cloud) where they can be installed as NPM packages, thus enabling an isolated environment for testing each component. If changes/updates are made for one project, then changes can be synchronized for other projects by updating the version for that particular component. This works by using Bit with React.

Important Considerations

Namespaces in various languages play an important role in facilitating code in order to work together. Having generic class names without namespaces can cause serious collision. To assist in reusing code, the module system must be lightweight with abilities to control versions, dependencies and namespace groups.

Conclusion

Considering current app development standards, it is almost always worthwhile to create reusable building blocks of code. This process is all about the people you’re building with, and in order to make code reusability quite simple and collaborative, the main key points are as follows:

• Design components as reusable segments
• Distribute components within your development community
• Use and distribute components as open source so that developers can adopt, modify, and collaborate

If you’re struggling to build out reusable components for your development team, Crowdbotics offers custom white label app development from expert PMs and developers. Get in touch with us today to receive a detailed quote and timeline.