Defer Channel Preview Load

Introduction

By default, when you open a channel in the Experience manager, its home page is loaded straight away in the preview. For most channels this is convenient, but for some it isn't: the home page may be slow to render, or it simply isn't a useful starting point for editors who almost always work on other pages.

A channel can be configured to defer this initial load. When deferred, opening the channel does not render the home page. Instead the preview stays empty with a short hint, and the Sitemap panel opens automatically so the editor can pick
the page they want to work on. As soon as a page is opened, the channel behaves exactly as normal.

This is an opt-in, per-channel setting and is turned off by default, so existing channels are unaffected.

What editors see

When a channel with deferred preview load is opened:

• The preview area shows the message "No page loaded. Use the Sitemap on the left to open a page." instead of a rendered page.
• The Sitemap panel on the left opens automatically.
• The Channel and Page menus in the toolbar are visible but disabled, because there is no page to act on yet.

Once the editor selects a page from the Sitemap, that page is rendered in the preview, the toolbar menus become available, and editing continues as usual.

Opening a specific page directly — for example through a deep link or by choosing "View in channel" from a document — is never deferred. The requested page always loads immediately.

How to enable it

Deferred preview load is controlled by the boolean property hst:deferpreviewload on a channel's hst:channel node. Set it to true to enable deferral for that channel:

/hst:hst:
  /hst:configurations:
    /example:
      /hst:channel:
        jcr:primaryType: hst:channel
        hst:name: Example
        hst:deferpreviewload: true

You can also set the property directly on the hst:channel node from the console.

To restore the default behavior (load the home page on open), set the property to false or remove it.