Abbbas Roholamin

Thinking in React: Building a User Interface

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Abbas Roholamin
·

3 min read

When constructing a user interface (UI) with React, you’ll follow a systematic approach to ensure your application is modular and maintainable. This process involves breaking down the UI into components, defining their various visual states, and enabling data flow across those components. Below are the steps involved, along with examples for each.

Step 1: Break the UI into a Component Hierarchy

Description: Start by identifying the different parts of your UI and breaking them down into a hierarchy of components. Each component should represent a piece of the UI that can be independently developed.

Example: Consider a simple to-do application. The main components might include:

  • App (Parent Component)

  • TodoList (Child Component)

  • TodoItem (Child Component of TodoList)

  • AddTodo (Child Component for adding new tasks)

      const App = () => {  
      return (  
          <div>  
              <h1>My To-Do List</h1>  
              <AddTodo />  
              <TodoList />  
          </div>  
      );  
  };

Step 2: Build a Static Version in React

Description: Create a static version of your UI using all the components defined in Step 1, without adding any state or interactivity at this stage.

Example: Render the TodoList with a few static TodoItem components.

const TodoList = () => {  
    return (  
        <ul>  
            <TodoItem text="Learn React" />  
            <TodoItem text="Build a To-Do App" />  
        </ul>  
    );  
};  

const TodoItem = ({ text }) => {  
    return <li>{text}</li>;  
};

Step 3: Find the Minimal but Complete Representation of UI State

Description: Identify the state necessary for your application, ensuring it is minimal yet sufficient to represent the UI accurately. Consider what data will affect rendering and user experience.

Example: For the to-do app, you need a list of tasks. The state can be an array of to-do objects.

const [todos, setTodos] = useState([  
    { id: 1, text: "Learn React", completed: false },  
    { id: 2, text: "Build a To-Do App", completed: false },  
]);

Step 4: Identify Where Your State Should Live

Description: Determine the most appropriate component to manage the state you identified in Step 3. The component that needs to modify the state or passes it down should own it.

Example: In the to-do app, the App component should hold the todos state since it needs to display the list and manage the addition of new to-dos.

const App = () => {  
    const [todos, setTodos] = useState([  
        { id: 1, text: "Learn React", completed: false },  
        { id: 2, text: "Build a To-Do App", completed: false },  
    ]);  

    return (  
        <div>  
            <h1>My To-Do List</h1>  
            <AddTodo addTodo={setTodos} />  
            <TodoList todos={todos} />  
        </div>  
    );  
};

Step 5: Add Inverse Data Flow

Description: Implement a system where child components can notify parent components of changes, effectively allowing the parent to update its state based on the child's interactions. This creates a two-way communication that is crucial for dynamic UIs.

Example: Modify the AddTodo component to take an addTodo function as a prop, so it can add new tasks to the to-do list.

const AddTodo = ({ addTodo }) => {  
    const [inputValue, setInputValue] = useState("");  

    const handleAdd = () => {  
        addTodo((prevTodos) => [  
            ...prevTodos,  
            { id: Date.now(), text: inputValue, completed: false },  
        ]);  
        setInputValue(""); // Clear input after adding  
    };  

    return (  
        <div>  
            <input  
                type="text"  
                value={inputValue}  
                onChange={(e) => setInputValue(e.target.value)}  
            />  
            <button onClick={handleAdd}>Add Todo</button>  
        </div>  
    );  
};

By following these steps, you can effectively think in React and build well-structured, dynamic user interfaces. Each step lays the groundwork for the next, ensuring a clear path from concept to implementation. If you need further clarification or additional components for the examples, just let me know!

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