8 AngularJS Development Mistakes to Avoid

Single Page Applications (SPAs) have become popular with the end-users as they do not need to be reloaded during use and work within a browser. The examples of Facebook, Gmail, Google Drive, Google Map, GitHub, and Twitter are testimony to their growing usage within the user community due to their quick loading speed. And to build such SPAs, the open-source JavaScript-based web application framework AngularJS is arguably the most suitable. This is due to the fact that AngularJS helps in prototyping scalable applications on multiple devices and deliver great user experiences. The front-end developers have their task cut out as they have to prioritize UX while handling performance, styles, SEO, integration with third-party applications, XHRs, application logic (models, views, and controllers), animations, and structure, among others.

AngularJS comes across as a handy web application framework for developers to manage the above-mentioned challenges encountered during the building of SPAs. It allows the writing and testing of JavaScript, CSS, and HTML codes to create multiple features in scalable applications. However, while trying to ace the development and implementation of SPAs, AngularJS developers often end up committing errors instead of utilizing the capability of the framework to its fullest extent. In this blog, we highlight a few such avoidable errors, which AngularJS developers end up committing with adverse consequences.

Top errors usually made by AngularJS developers

The inadvertent and unwarranted errors committed by AngularJS developers prevent them from realizing the potential of this framework. Let us discuss them in detail:

# Below-par utilization of available tools: AngularJS offers plenty of tools to build and execute functions, which otherwise become difficult and a time-consuming affair. To cite an example, browsers like Chrome and Firefox include development strings that help in debugging, profiling, and generating error output. This specific tool can help developers quickly find errors in the code during the development process and save time. In another example, errors related to AngularJS are printed on the console log, which developers should check before coming out with solutions. For more information, read our specific blog on the top tools to be used for AngularJS projects.

# Watchers’ count: Every binding in AngularJS creates a watcher function that is called during the digest cycles to return a value. If the returned value is not similar to the one in the previous call, the call-back passed in the second parameter gets executed. Since comparison and evaluation are done for previous bindings at each digest phase the watchers’ count becomes huge. The sheer number of such watchers’ count slows down the web application’s performance in the browser. So it’s better to limit the usage of watchers’ count in order to ensure a smooth performance of the web app. Also, one can write a code that counts the number of watchers to be optimized later.

# Directly modifying the DOM: One of the commonest things developers often resort to while creating web pages or apps is manipulating the document structure by using DOM or the Document Object Model, which is the API for XML and HTML documents. Manipulating DOM is important during the working of JavaScript for reasons such as:

• The need to refresh the page title based on the change of context
• The need to execute SVG or Scalable Vector Graphics to develop flexible images for mobile web applications with responsive design
• To focus on control after a validation error has taken place

Thus, in order to deal with the above possibilities, developers offering AngularJS development services take the easy way out of manipulating DOM directly from the controller as the controller offers access to JavaScript for view first through $scope functions. However, this practice can lead to security issues such as XSS attacks and tight coupling between the application and rendering layers thereby making it impossible to separate the two and deploy the application into a web worker. Instead, the accepted libraries jQuery or Renderer2 service can be used.

# Declaring functions without proper names: There may be instances where developers do not ascribe names to functions while coding. This is important to ensure the maintainability of the code and help developers to avoid any rework afterward.

# Pre launch testing: Before releasing the application to the end-users, it should be tested across browsers to identify unexpected bugs. However, this step is often given a go by due to the pressure of release and consequently, the application fails to generate the much-needed superior user experience. Hence, to test the application in different environments, the following steps should be pursued:

a) Use $applyAsync: It helps to schedule a new digest in the very near future and detains the expression resolutions to the next digest cycle. $applyAsync can be accessed both manually and in automated ways.

b) Use Batarang: As a pre-eminent Google Chrome extension, Batarang is employed to develop and debug Angular apps. It offers model browsing to look inside the models that AngularJS has bound to scopes. It helps when working with directives and executing scope abstractions to view the bounded values. Besides, it provides a dependency graph, which helps to determine the services to be prioritized.

# Scope binding: The scope of AngularJS relates to the built-in objects having the application data. And since the features of AngularJS are dependent on the MVC architecture, it is the scope that binds the controller and view. To ensure smooth development and a proper binding system, the developers should assemble the scope objects properly. Further, in AngularJS, the value passes as primitives while reference passes as non-primitives. To resolve this issue, it is advised to assemble all scoping objects accurately to avoid any complications later.

# Handling the code: The SDLC entails the equal distribution of codes into small compartments or cubicles to ensure easy tracking of errors later. Ideally, in the controller, minimal compartments should be made for each area of the application. However, since AngularJS comprises an MVC architecture, there are chances of bundling all the excessive codes together into a single controller. This can create code organization issues for a team of developers working to build the application. A well-organized code can help every member of the team to work on and identify errors, and make it adaptable for scalability later on.

# Failure to unsubscribe: One of the key requirements in developing web or mobile applications using AngularJS is subscribing to new tools and libraries. And once the utility of such subscriptions is over, they should be done away with. However, unsubscribing from such requirements may not always be the case after development mostly due to oversight. Consequently, the application may be subjected to data security risks.

Conclusion
AngularJS has emerged as an exceptional front-end framework to develop Single Page Applications, and other solutions. Due to its scalability and backing by Google, there is plenty of community support surrounding it. However, developers are prone to commit some common mistakes, which can make the application vulnerable to security and other issues and impact the user experience negatively. Nowadays, the clients have high expectations and they possess some technical understanding. They are ready to pay some more when they hire Angular developers in exchange of high-quality and flawless service. Therefore, the developers should take note of such mistakes and ensure the application turns out to be robust, secure, feature-rich, and easy-to-use.