Mendix Application Development – Continuous Refactoring

While designing the application we need to consider the multiple aspect of the application to reduce efforts put into maintaining the app as well it will be easy to adopt the changes while the development all the refactoring pain points can be considered while designing itself it will be easy to do the same in the future also we can avoid the rework.

To make sure this we should try creating small modules in the app for specific parts which will be dedicated to respective functionality. All the dedicated entities should reside in respective modules so that access control and security configuration will be easy. Refactoring will be required throughout the development, it can be due to multiple reasons like requirement change, complexity increases on specific features and if we do not refactor the code, it will be difficult to maintain the app in feature.

Two major refactoring in Mendix involves the Domain Model and Microflow

Domain Model Refactoring

In Traditional development we call it normalization, it is a process of organizing data in a relational database to reduce redundancy, improve data integrity and minimize the risk of data inconsistencies. It involves breaking down larger tables into smaller, more manageable ones that are linked through associations and constraints. The goal of normalization is to optimize data storage and retrieval performance and improve the overall efficiency and scalability of the database.

Similarly, normalizing a domain model in Mendix involves breaking down large or complex entities into smaller, more manageable ones that are better optimized for data storage and retrieval. The goal is like normalization, which is to minimize redundancy, improve data integrity, and reduce the risk of data inconsistencies.

Unfortunately, many Mendix developers doesn’t aware traditional database development which leads unnecessary entities, relationship between entities, usage of the persistent and non-persistent entities.

At a high level to refactor a domain model in Mendix, developers can follow best practices such as:

1. Identifying entity dependencies: Developers should identify which entities depend on others and how they are related. This information can be used to determine which entities should be broken down and how they should be linked.
2. Analyzing entity attributes: Developers should analyze the attributes of each entity to identify any redundant or duplicate information. Attributes that are common across multiple entities can be moved to a separate entity and linked using associations.
3. Normalizing relationships: Developers should use best practices for entity relationships, such as many-to-many associations, to ensure that the data is structured in a way that is easy to manage and retrieve.
4. Defining constraints: Developers should define constraints such as primary keys, unique keys, and foreign keys to ensure that data is stored and retrieved correctly and efficiently.
5. Testing and validation: Developers should thoroughly test and validate the normalized domain model to ensure that it is functioning as expected and that there are no data inconsistencies.

Refactoring a domain model in Mendix can be a challenging process that requires careful planning and execution. The domain model is a critical part of a Mendix application, and any changes to it can have a significant impact on the application’s functionality, performance, and scalability. Some of the challenges that developers may face when refactoring a domain model in Mendix include:

1. Data migration: When making changes to a domain model, developers may need to migrate data from the old model to the new one. This can be a complex process that requires careful planning and execution to avoid data loss or corruption.
2. Impact Analysis: Changes to a domain model can have a ripple effect on other parts of the application, such as microflows, pages, and widgets. Developers need to carefully review and update these components to ensure that they are compatible with the new domain model.
3. Testing: Refactoring a domain model can introduce new bugs or issues, which can be difficult to identify and fix. Developers need to thoroughly test the application to ensure that it is functioning correctly after the changes have been made.
4. Time and resource constraints: Refactoring a domain model can be a time-consuming process that requires a significant amount of developer resources. This can be challenging in cases where there are strict deadlines or limited development resources.

To address these challenges, developers can follow Standard operating procedure (SOP) such as creating a backup of the existing domain model before making changes, carefully planning and testing data migration, and using automated testing tools to identify and fix issues. Additionally, developers can work closely with stakeholders and end-users to ensure that any changes to the domain model are aligned with business requirements and do not impact the end-user experience.

Refactoring Microflow

This process involves restructuring and optimizing microflows to improve their performance, maintainability, and scalability. Microflows are a fundamental building block in Mendix application development, and they are used to model business processes and workflows. Over time, as the application grows and evolves, microflows can become complex and difficult to manage, leading to issues such as poor performance, increased technical debt, and reduced maintainability. E.g., Each microflows should be dedicated to achieving one functionality and you can call multiple SubMicroflows in Main microflows to achieve the complete goal. Any business logic can be used at multiple places should be moved to SubMicroflows.

To address these issues, Mendix developers should regularly review and refactor their microflows. This involves breaking down complex microflows into smaller, more manageable ones, simplifying conditional expressions and loops, removing unnecessary actions, and optimizing queries and other data access operations.

There are several benefits of microflow refactoring in Mendix. Firstly, it can improve the performance of the application by reducing the number of database queries and optimizing data retrieval and manipulation. Secondly, it can improve the maintainability of the application by making microflows easier to understand and modify, reducing the risk of bugs and other issues. Finally, it can improve the scalability of the application by ensuring that microflows can handle increased loads and volumes of data.

To perform microflow refactoring in Mendix, developers should follow Mendix provided guidelines such as defining clear naming conventions, breaking down microflows into smaller, more manageable ones, avoiding unnecessary complexity, and using best practices for data access and manipulation. Additionally, developers can use tools such as the Mendix Modeler to analyze the complexity of their microflows and identify areas that need optimization.

Additionally, the following can be considered as refactoring in Mendix.

Refactoring Application

• Functional Use case, one module will be dedicated to one specific functional requirement, applying SOLID principles.
• System Admin configuration can be moved to one module.
• Separate Module for each Integration with External App /API
• Design Proper Folder Structure in Each module to Maintain the Business Logic, UI Pages
• Separate Folder for each functionality under that folder separate folder for validation logic, business logic, pages
• Move the common code of the pages into Snippets.

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Conclusion

Refactoring is an important process in Mendix development that involves improving the design, structure, and quality of the application to improve maintainability, performance, and scalability. However, it is essential to ensure that the refactoring process does not result in rework, which can occur when changes are not properly planned or executed.

To avoid rework during Mendix refactoring, it is crucial to consider design considerations such as architecture, data models, and software patterns. These design considerations help to ensure that the refactoring process is executed in a way that is compatible with the existing codebase, and that the changes made do not introduce new bugs or issues.

For example, when refactoring a Mendix application, developers should consider the existing architecture and ensure that the changes made align with the overall design principles of the application. They should also consider the data models used in the application and ensure that any changes made do not impact data integrity or consistency.