Django If Else

Conditional Statements

{% if condition %}
  ...
{% endif %}

{% if condition %}
  ...
{% else %}
  ...
{% endif %}

{% if condition1 %}
  ...
{% elif condition2 %}
  ...
{% endif %}

==, !=, <, >
<=, >=
and, or, not

🔹 Simple If Statement

The basic if statement checks a condition and displays content only when the condition evaluates to true. This is the foundation of conditional rendering in templates.

🔸 View

def home(request):
    context = {
        'is_logged_in': True,
        'username': 'Alice'
    }
    return render(request, 'home.html', context)

🔸 Template

{% if is_logged_in %}
    <h2>Welcome back, {{ username }}!</h2>
    <p>You are logged in.</p>
{% endif %}

🔹 If Else Statement

The if else statement provides an alternative when the condition is false. Display different content based on whether the condition passes or fails for complete control.

🔸 View

def profile(request):
    context = {
        'is_premium': False
    }
    return render(request, 'profile.html', context)

🔸 Template

{% if is_premium %}
    <div class="premium-badge">
        <h3>⭐ Premium Member</h3>
        <p>Enjoy all premium features!</p>
    </div>
{% else %}
    <div class="free-badge">
        <h3>Free Member</h3>
        <p>Upgrade to premium for more features.</p>
    </div>
{% endif %}

🔹 If Elif Else Statement

Use elif to check multiple conditions sequentially. Django evaluates each condition in order and executes the first matching block, perfect for handling multiple scenarios efficiently.

🔸 View

def dashboard(request):
    context = {
        'score': 85
    }
    return render(request, 'dashboard.html', context)

🔸 Template

{% if score >= 90 %}
    <p class="grade">Grade: A - Excellent!</p>
{% elif score >= 80 %}
    <p class="grade">Grade: B - Good job!</p>
{% elif score >= 70 %}
    <p class="grade">Grade: C - Fair</p>
{% else %}
    <p class="grade">Grade: F - Need improvement</p>
{% endif %}

🔹 Comparison Operators

Django templates support various comparison operators for building conditions. Use these operators to compare values and create sophisticated conditional logic in your templates.

<!-- Equal to -->
{% if age == 18 %}
    <p>You are exactly 18 years old.</p>
{% endif %}

<!-- Not equal to -->
{% if status != "pending" %}
    <p>Status is not pending.</p>
{% endif %}

<!-- Greater than -->
{% if price > 100 %}
    <p>Expensive item</p>
{% endif %}

<!-- Less than or equal to -->
{% if quantity <= 5 %}
    <p>Low stock warning!</p>
{% endif %}

🔹 Logical Operators

Combine multiple conditions using logical operators. The and, or, and not operators allow you to create complex conditional statements for advanced template logic.

🔸 AND Operator

{% if is_logged_in and is_premium %}
    <p>Access granted to premium content</p>
{% endif %}

🔸 OR Operator

{% if is_admin or is_moderator %}
    <p>You have moderation privileges</p>
{% endif %}

🔸 NOT Operator

{% if not is_banned %}
    <p>Welcome to the community!</p>
{% endif %}

🔸 Combined Operators

{% if age >= 18 and country == "USA" or has_permission %}
    <p>Access granted</p>
{% endif %}

🔹 Checking Variable Existence

Check if variables exist or have values before using them. This prevents errors and allows graceful handling of missing or empty data in your templates.

<!-- Check if variable exists -->
{% if username %}
    <p>Hello, {{ username }}!</p>
{% else %}
    <p>Hello, Guest!</p>
{% endif %}

<!-- Check if list is not empty -->
{% if items %}
    <p>You have {{ items|length }} items</p>
{% else %}
    <p>Your cart is empty</p>
{% endif %}