Add WARNING section when documentation is marked as deprecated

[GaneshPatil7517]

This PR implements automatic rendering of a WARNING section on documentation pages when the page metadata marks the component (or language, data format, misc) as deprecated.

When a documentation page includes the :deprecated: attribute in its AsciiDoc header, a prominent warning block will automatically appear at the top of the page (below the title), alerting users that the documented component/feature is deprecated.

Changes

Modified antora-ui-camel/src/partials/article.hbs to conditionally render a deprecation warning block:

• Checks if the page has the deprecated attribute set
• Renders an AsciiDoc-style WARNING admonition block with consistent styling
• Uses the component's :shortname: if available, otherwise falls back to the page title
• No manual changes required in individual AsciiDoc files
• Applies to all documentation types: components, languages, data formats, misc

Implementation Details

The solution:

1. Uses Handlebars' {{#unless}} block to check if the deprecated attribute is undefined
2. Renders the warning using the existing admonition block styling (.admonitionblock.warning)
3. Follows the Antora/AsciiDoc standard table structure for admonitions
4. Leverages the {{or}} helper to display shortname or fallback to page title

Example

For a page with:

= My Component
:shortname: mycomponent
:deprecated: true

The rendered page will display:

┌──────────────────────────────────────────┐
│ ⚠️  Warning                               │
│ This mycomponent is deprecated            │
└──────────────────────────────────────────┘

Testing

Locally tested:

• Built the Antora UI and website with the template changes
• Verified that pages with :deprecated: true show the warning
• Confirmed non-deprecated pages remain unchanged
• CSS styling from existing admonition block styles is applied correctly

References

Closes #1477

[Copilot]

Pull request overview

This PR adds automatic rendering of a deprecation warning at the top of documentation pages when the :deprecated: attribute is set in the page metadata.

Changes:

• Modified the Handlebars template to conditionally display a WARNING admonition block when page.attributes.deprecated is defined
• The warning displays the component's shortname (or page title as fallback) with a deprecation message

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[Copilot]

The icon structure doesn't match the expected AsciiDoc admonition format. According to the CSS in src/css/doc.css (lines 359-369), the icon should contain an <i> element with a title attribute. The CSS rule .doc .admonitionblock .icon i::after uses content: attr(title) to display the icon label. Replace <div class=\"title\">Warning</div> with <i title=\"Warning\"></i> to match the standard AsciiDoc admonition structure.

Suggested change

	<div class="title">Warning</div>
	<i title="Warning"></i>

[Copilot]

The message uses raw page.title as fallback, which will include HTML markup since page.title can contain formatted text. This could result in HTML tags being displayed in the deprecation message. Consider using a plain text attribute or sanitizing the output to avoid displaying HTML markup in the warning message.

Suggested change

	This {{or page.attributes.shortname page.title}} is deprecated
	This {{or page.attributes.shortname 'page'}} is deprecated

[Copilot]

The condition checks if deprecated is NOT undefined, which means the warning will appear for any truthy value or even empty string. According to the issue #1477, the attribute should be explicitly checked for a truthy value. Consider using {{#if page.attributes.deprecated}} instead, which provides clearer intent and properly handles falsy values.

[github-actions]

🚀 Preview is available at https://pr-1479--camel.netlify.app

[GaneshPatil7517]

hey @davsclaus exicted to see it merged...

[davsclaus]

I do not see that deprecated warning such as
https://pr-1479--camel.netlify.app/components/4.14.x/nitrite-component.html

[davsclaus]

this is wrong as it edits an article.hbs file which is not related to camel components. I think this should be done in camel-core/docs folder, where the components / languages et all are

[davsclaus]

this is wrong as it edits an article.hbs file which is not related to camel components. I think this should be done in camel-core/docs folder, where the components / languages et all are

[GaneshPatil7517]

Hi @davsclaus,

Thanks for the review feedback! I've updated the implementation.

The issue was: The article.hbs template was checking for page.attributes.deprecated, but Antora only exposes document attributes with the page- prefix to templates. The component docs in camel-core use :deprecated: (without the prefix), so the attribute wasn't accessible.

The fix: I created an Antora extension (promote-deprecated-attribute.js) that promotes the document attributes to page attributes:

:deprecated: → page-deprecated
:supportlevel: → page-supportlevel
:shortname: → page-shortname
This way the template can access them via page.attributes.deprecated and display the warning banner. The extension is registered in antora-playbook.yml.