# Activity Diagram

In software development, maintaining and expanding a large project requires close collaboration among team members. A deep understanding of the application's structure and workflow is key to ensuring performance and work quality. **Activity Diagrams** play a crucial role in this process, helping both new developers and those who haven't interacted with the project for a while quickly grasp the system and contribute effectively.

## **Benefits of Activity Diagrams**

### **Helping New Members Quickly Get Familiar with the Project**

* **Understanding the System Overview:**
  * Activity diagrams provide a comprehensive view of the application's workflow and logic.
  * Helps reduce onboarding and initial training time.
*   **Reducing Misinterpretation:**

    * Prevents misunderstandings about functionality or data flow due to complex code.
    * Establishes a common language among team members.



### **Supporting Developers Returning to a Feature After a Long Time**

* **Quickly Recalling the Flow:**
  * After a long break from working on a specific feature, even the original developer might struggle to remember its details.
  * Activity diagrams help them quickly recall how it works and its associated logic.
* **Saving Time:**
  * Reduces the time needed to reread old code and documentation.
  * Allows developers to focus on solving the current problem or improving features.

### **Easier Code Understanding and Bug Tracing**

* **Identifying Key Nodes and Bottlenecks:**
  * Activity diagrams clearly show system transitions, helping pinpoint potential error locations.
  * Supports data flow and system state analysis.
* **Collaboration in Debugging:**
  * Provides a shared reference for discussing issues among team members, especially since different members may handle different parts of the project.
  * Improves teamwork efficiency in debugging and optimizing the code.

### **Assisting in Feature Design and Expansion**

* **Effective Planning:**
  * Before implementing a new feature, an activity diagram helps visualize how it integrates into the existing system.
  * Predicts potential impacts and risks.

👉 Personally, this is the most valuable aspect of using Activity Diagrams. When dealing with complex flows or new features, sketching them out beforehand has significantly reduced coding time and minimized potential errors.



## **How to Build an Effective Activity Diagram**

### **Using the Right Tools**

* **Visual Tools:**
  * Use software like **Lucidchart, Draw.io,** or **Microsoft Visio** to create diagrams.
  * Ensure that diagrams are **clear, easy to read, and shareable**.
  * A commonly used tool that I recommend is **Visual Paradigm**: [https://online.visual-paradigm.com/](https://online.visual-paradigm.com/).
  * Make sure the diagram **accurately reflects** the current state of the system.
  * Update it whenever there are **workflow changes or new features** added.

### **How to Trace Code Flow**

Before implementing your code, make sure you have drawn a **well-structured activity diagram**. This helps ensure that the logic is solid before you start coding. Of course, you might need to adjust the flow during development if certain aspects turn out to be impractical.

* **From Diagram to Code**
  * Besides using debugging tools to check if the application is running correctly, you can leave logs to create a **list of logs** that visually tracks the execution flow. These logs can also be **saved to a text file**, making it easier to review issues later.\
    ![](https://2074953091-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F63bX4jdEctx3wiLiur0x%2Fuploads%2FtGxm8RbrSe5dqTkI5RsV%2Fimage1.png?alt=media\&token=035afd6a-d24c-4723-af03-31d216af70cb)
  * I use **specific action codes** as log content and then print them to the console.
  * Example: `"AQP 20 | show EndDrawer Payment"`.
    * **AQP** = custom function code.
    * **20** = step number.
    * **show EndDrawer Payment** = description of the current process.
*   **How to Create Easily Observable Logs**

    * Flutter’s default logs can be **difficult to read**. I wrote an article about adding **color to logs**, making them more readable. Check it out here: [https://wong-coupon.gitbook.io/flutter/easy-code/log-color](https://wong-coupon.gitbook.io/flutter/easy-code/log-color).
    * By structuring logs clearly, **each step in the activity diagram** can be easily mapped to the logs. This makes it significantly easier to **identify bugs** when issues arise in the app.
    * **Storing logs in the device’s memory** can be especially useful when debugging a released app.

    <figure><img src="https://2074953091-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F63bX4jdEctx3wiLiur0x%2Fuploads%2FpeVwI4Gzjab6YtcWQnf9%2Fimage2.png?alt=media&#x26;token=f7702b1d-a49f-49a3-8f2d-049e62799f62" alt=""><figcaption><p><strong>Observable Logs</strong></p></figcaption></figure>

{% content-ref url="log-color" %}
[log-color](log-color)
{% endcontent-ref %}

## **Conclusion**

This method has saved me and my development team **a significant amount of time** when debugging, especially when we don’t have access to live debugging tools or need to investigate issues in a released app. **Activity diagrams are a powerful tool** for improving efficiency and quality in software development. By providing a **clear, visual representation** of the system, they help both **new and experienced developers** quickly understand the code structure and work more effectively.

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