Understanding Component in Visualforce

The <apex:pageMessage> component is used to display simple messages on a Visualforce page. It is typically used for success, error, or information messages that need to be shown to users.

Syntax

xmlCopyEdit<apex:pageMessage summary="Your message here" severity="info" />

Key Attributes

Example 1: Basic Usage

xmlCopyEdit<apex:page>
    <apex:pageMessage summary="This is an informational message." severity="info" />
</apex:page>

• This will display an informational message on the page.

Example 2: Success Message

xmlCopyEdit<apex:page>
    <apex:pageMessage summary="Your data has been saved successfully!" severity="success" />
</apex:page>

• A success message shows up after an action (like saving data) is completed.

Example 3: Error Message with Detail

xmlCopyEdit<apex:page>
    <apex:pageMessage summary="Error occurred during the process!" severity="error" detail="Unable to connect to the database." />
</apex:page>

• Error messages can include detailed explanations to guide users.

When to Use <apex:pageMessage>

• Display status or result messages after form submission or actions.
• Show important user feedback (errors, warnings, or success notifications).

Best Practices

• Use severity="info" for general messages and severity="error" for critical issues.
• Avoid overloading users with too many messages; use sparingly to avoid clutter.
• Always use summary for concise messages and detail for additional information.