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Data Models

Data models are essential building blocks when you're working with structured data in your app. In Nowa, you can visually create and manage data models that represent real-world objects—like a task, a product, a user profile, or a log entry—and then use them across your app in variables, logic, and UI.

📌 Why You Need Data Models​

Here are common scenarios where creating a model is necessary:

  • To-do apps: Each task needs a structure like title, description, and status.
  • E-commerce apps: A product has properties like name, price, and image.
  • User management: A user might have a name, email, and role.
  • Water tracker app: Each water log entry can have an amount and timestamp.

Creating models helps you avoid repeating data structures manually and makes your app more scalable and easier to maintain.

✨ How to Create a Data Model​

  1. Click on the ➕ next to the lib folder in the Files panel.

  2. Choose "Create new object".

  3. A popup will appear. Enter the model name (e.g., Task).

    At the bottom of the popup:

    • Path: shows where the Dart file will be created.
    • Class: shows the Dart class name you’ll use in your logic and variables.

  4. After confirming, the model will appear in the Files panel as a Dart file.

Naming Rules

The file and class names are automatically adjusted:

  • A model named "task model" becomes:
    • Class name: TaskModel (PascalCase)
    • File name: task_model.dart (snake_case)

This follows Dart’s best practices.

✍️ Adding Variables and Functions​

  1. Single-click the model file to open a popup showing variables and functions.
  2. Click ➕ next to either section to create a new variable or function.

In the popup:

  • Choose the variable name and type.
  • Set a default value (optional).
  • Enable is final if the variable should not change after being set.
When to use final

Use final when:

  • The value shouldn’t change, like id, createdAt.

Avoid final when:

  • You want to update it later, like title, description, isDone.

In the video above, we:

  • Created title, description, and isDone variables for the Task model.
  • Set all as non-final so users can update them.
  • Added a method markAsComplete to mark a task as done.

🧑‍💻 View and Edit the Model Code​

  1. Double-click the model file to open its Dart code.
  2. You can here view the source-code of the model, or edit or add variables and functions here directly. To do so:
    • Double-click the file name.
    • Click ➕ next to the model name to add or edit variables/functions.

In the video, we:

  • Opened task.dart.
  • Added a new variable priority of type int.
  • Instantly saw the code update.

🔁 Using Data Models​

1. As a Data Type​

You can use your model as a custom type for cases like:

  • Variables
  • Parameters
  • Function parameters and returns

Example:

  • We created a list variable taskList of type List<Task>.
  • Set a default value with 3 tasks.
  • Modified each task’s properties (title, description, etc.).
Default Value Use

The default value is used only when no other value is set during runtime. It’s great for testing your UI layout.

2. Creating Instances in Circuit​

In the logic editor (Circuit):

  • Use the "Create" node.
  • Choose the model you want to instantiate.
  • Fill in its properties.

Example:

  • In the On Pressed event of a ➕ button:
    • Created an instance of Task.
    • Set values for title, description, and isDone.
    • Stored it in a variable task.
    • Added it to the taskList.
Dynamic Input

To use dynamic values (like user input):

  • Click on a property (e.g. title) in the instance node.
  • Open the linking menu. Choose what you want to link it with—it can be a variable, a parameter, the result of a function call, an expression, and more.

For example, if you have a TextField widget with a controller variable named titleTextFieldController, and you want to use the entered text as the title of the Task instance, open the linking menu, then go to locals > titleTextFieldController > text to bind the text input of the TextField to be the title of the task created

Full Example: Water Tracker App

We used a model WaterLogEntry to represent a log of water intake, with:

  • amount: The amount of the intake as int
  • date: the date where the instance was created, from the type DateTime.

We then created variables and used this model in the logic and UI.

Play this tutorial that will start from 6:00 to see how an object was created and used during building a Water Tracker App.

Data models in Nowa make your app logic cleaner, more powerful, and easier to scale. Whether you're building a todo list, an e-commerce app, or a fitness tracker, models are your best friend to organize and work with structured data.