Understanding apex:attribute Component in Visualforce

The <apex:attribute> component is used within custom components to define attributes (parameters) that can be passed from a Visualforce page to that component.

It helps make custom components flexible and reusable by accepting dynamic values.

Syntax

xmlCopyEdit<apex:component>
    <apex:attribute name="recordName" type="String" description="Name of the record" required="true"/>
    Hello, {!recordName}
</apex:component>

Key Attributes

Example 1: Creating a Custom Component With Attribute

MyComponent.component

xmlCopyEdit<apex:component>
    <apex:attribute name="userName" type="String" description="User's Name" required="true" />
    <h2>Welcome, {!userName}!</h2>
</apex:component>

Usage in a Visualforce Page:

xmlCopyEdit<apex:page>
    <c:MyComponent userName="Mayank" />
</apex:page>

Example 2: Passing Dynamic Value

xmlCopyEdit<apex:page controller="MyController">
    <c:MyComponent userName="{!currentUserName}" />
</apex:page>

When to Use <apex:attribute>

• While creating custom Visualforce components.
• To allow data binding and dynamic rendering in reusable UI blocks.
• Ideal for modular design and code reusability.

Best Practices

• Always provide a description for maintainability.
• Use meaningful name attributes.
• Mark attributes required when necessary to avoid runtime issues.