Add ui-request-render-data message type for explicit render data requests

[Copilot]

This PR introduces a new ui-request-render-data message type that allows iframes to explicitly request render data from the host, providing a more semantic alternative to relying on the ui-lifecycle-iframe-ready lifecycle event side-effect.

Problem

Previously, iframes could only receive render data as a side-effect of sending ui-lifecycle-iframe-ready. This approach had several limitations:

• It felt like an unexpected side-effect rather than an explicit request
• Render data could only be requested during the ready lifecycle event
• Some users experienced reliability issues with the automatic delivery mechanism
• There was no way to re-request render data later in the iframe's lifecycle

Solution

The new ui-request-render-data message type allows iframes to explicitly request render data when needed:

// Iframe sends request
window.parent.postMessage({
  type: 'ui-request-render-data',
  messageId: 'optional-tracking-id'
}, '*');

// Host responds with standard render data message
// {
//   type: 'ui-lifecycle-iframe-render-data',
//   messageId: 'optional-tracking-id',
//   payload: { renderData: {...} }
// }

Implementation Details

• New message type: Added UI_REQUEST_RENDER_DATA: 'ui-request-render-data' constant
• HTMLResourceRenderer enhancement: Added message handling that responds with render data using the existing ui-lifecycle-iframe-render-data format
• Message ID support: Properly forwards messageId from request to response for tracking
• Backwards compatibility: Existing ui-lifecycle-iframe-ready behavior remains unchanged
• Comprehensive testing: Added test cases for both scenarios (with and without render data)
• Documentation: Updated embeddable-ui.md, resource-renderer.md, and react-usage-examples.md with detailed usage examples and alternative approaches

Benefits

• Semantic clarity: Explicit render data requests vs. lifecycle side-effects
• Flexible timing: Can request render data at any point, not just during initialization
• Request tracking: Optional messageId support for tracking requests/responses
• Reliability: Direct request/response pattern vs. automatic delivery
• Backwards compatible: No breaking changes to existing functionality

Fixes #106.

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[idosal]

@copilot add it to the documentation in resource-renderer.md and react-usage-example.md

[Copilot]

@copilot add it to the documentation in resource-renderer.md and react-usage-example.md

Added comprehensive documentation for the new ui-request-render-data message type to both resource-renderer.md and react-usage-examples.md. The documentation includes:

• Complete code examples showing the new explicit request pattern
• Benefits comparison vs the lifecycle-based approach
• Alternative sections added after existing render data examples
• Backwards compatibility maintained

See commit 0cc4457 for the documentation updates.

[Copilot]

Pull Request Overview

This PR introduces a new ui-request-render-data message type that allows iframes to explicitly request render data from the host, providing a more semantic alternative to the automatic delivery via ui-lifecycle-iframe-ready events.

• Adds explicit render data request/response mechanism with optional message ID tracking
• Maintains backwards compatibility with existing ui-lifecycle-iframe-ready behavior
• Provides comprehensive documentation updates with usage examples

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
HTMLResourceRenderer.tsx	Adds new message type constant and handler for explicit render data requests
HTMLResourceRenderer.test.tsx	Adds test coverage for both scenarios with and without render data
embeddable-ui.md	Documents the new message type with detailed usage examples
resource-renderer.md	Adds alternative approach documentation for explicit render data requests
react-usage-examples.md	Provides comprehensive React usage examples for the new message type

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