Preview pane fails to update automatically when editing Markdown content

[2400032703kotinijeswanth]

🐞 Coding Issue: Live Preview not updating

Description:
When editing Markdown files in the Decap CMS editor, the preview pane does not refresh automatically after content changes. Users must switch away from the editor or manually trigger a refresh to see updates.

Steps to Reproduce:

1. Open Decap CMS (self-hosted or demo version).
2. Create or edit a Markdown-based entry (e.g., blog post).
3. Type some text and wait for the preview to update.
4. Observe that the preview remains stale until focus is lost or a manual save occurs.

Expected Behavior:
The preview pane should update automatically as content changes are made in the editor.

Actual Behavior:
The preview remains outdated until a manual refresh or navigation change.

Possible Cause (Hypothesis):
The onChange handler for the Markdown editor may not be properly triggering a state update in the preview component. The issue could be in:

• decap-cms-core/src/components/Editor/EditorControlPane/EditorControlPane.js
• or the Redux store not propagating the change to the preview frame.

Proposed Fix:

• Ensure that the preview iframe listens for content updates from the editor.
• Add throttled state synchronization to improve performance.
• Validate that updatePreview() (or equivalent) fires on every content change event.

Environment:

• Decap CMS version: Latest (as of Nov 2025)
• Browser: Firefox 144.0 / Chrome 130+
• Hosting: Local test instance (npx decap-server)

Additional Context:
This issue affects the user experience when writing Markdown-rich content and can cause confusion for non-technical editors.