The <apex:pageMessages> component is used to display a collection of messages on a Visualforce page. It is typically used in scenarios where you need to show multiple messages to the user, such as a list of validation errors or multiple success notifications.
Syntax
xmlCopyEdit<apex:pageMessages />
Key Attributes
| Attribute | Description |
|---|---|
rendered | Optional. Specifies whether the component is displayed or not. Defaults to true. |
escape | Optional. Whether to escape HTML in messages. Defaults to true. |
showDetail | Optional. If true, shows the message details. If false, shows only the summary. |
Example 1: Basic Usage
xmlCopyEdit<apex:page>
<apex:pageMessages />
</apex:page>
- This will display all the page messages (info, error, warning, success) generated by the page.
Example 2: Displaying Messages with showDetail="false"
xmlCopyEdit<apex:page>
<apex:pageMessages showDetail="false" />
</apex:page>
- This will display only the summary text of the messages, without showing any additional details.
Example 3: Displaying Multiple Messages
xmlCopyEdit<apex:page>
<apex:pageMessage summary="Warning! Please check your input." severity="warning" />
<apex:pageMessage summary="Success! Your data is saved." severity="success" />
<apex:pageMessages />
</apex:page>
- Multiple messages (info, success, warning, etc.) will be displayed on the page.
When to Use <apex:pageMessages>
- When you need to show multiple messages (error, success, etc.) at once.
- Useful for displaying validation errors or results of bulk operations.
Best Practices
- Use
<apex:pageMessages>when you want to display a list of messages that have been added to the page context. - Avoid cluttering the page with too many messages; group them logically for better user experience.
- Be mindful of message severity and try not to overwhelm the user with too many warnings or errors at once.