Developer Mode developer-mode

When editing pages in AEM, several modes are available, including Developer mode. Developer mode opens a side panel with several tabs that provide a developer with technical information about the current page.

There are two tabs:

  • Components for viewing structure and performance information.
  • Errors to see any problems occurring.

These help a developer to:

  • Discover how the pages are composed.
  • Debug: what is happening where and when, which in turn helps to resolve issues.
Developer mode:
  • Is not available on mobile devices or small windows on desktop (due to space restrictions).
    • This occurs when the width is less than 1024px.
  • Is only available to users who are members of the administrators group.

Opening Developer Mode opening-developer-mode

Developer mode is implemented as a side panel to the page editor. To open the panel, select Developer from the mode selector in the toolbar of the page editor:

Opening developer mode

The panel is divided into two tabs:

  • Components - This shows a component tree, similar to the content tree for authors
  • Errors - When problems occur, details are shown for each component.

Components Tab components

Components tab

This shows a component tree that:

  • Outlines the chain of components and templates rendered on the page. The tree can be expanded to show context within the hierarchy.

  • Shows the server-side computational time needed to render the component.

  • Lets you expand the tree and select specific components within the tree. Selection provides access to component details; such as:

    • Repository path
    • Links to scripts (accessed in CRXDE Lite)
    • Component detail as seen in the Components Console
  • Components selected in the tree are indicated by a blue border in the editor.

This components tab helps to:

  • Determine and compare the rendering time per component.
  • See and understand the hierarchy.
  • Understand, and then improve, the page loading time by finding slow components.

Each component entry may have the following options:

Developer mode component example

  • View Details: A link to a list that shows:

    • All component scripts used to render the component.

    • The repository content path for this specific component.

      View Details

  • Edit Script: A link that opens the component script in CRXDE Lite.

  • View Component Details: Opens the details of the component within the Components Console.

Expanding a component entry by tapping or clicking the chevron can also show:

* The hierarchy within the selected component.
* Rendering times for the selected component in isolation, any individual components nested within it, and the combined total.

Errors Tab errors

The errors tab

Hopefully the Errors tab will always be empty (as above), but when problems occur the following details may be shown for each component:

  • A warning if the component writes an entry to the error log, together with details of the error and direct links to the appropriate code within CRXDE Lite.
  • A warning if the component opens an admin session.

For example, if an undefined method is called, the resulting error is shown in the Errors tab and the component entry in the tree of the Components tab will also be marked with an indicator when an error occurs.