Call Hierarchy Pane

Last modified: May 7, 2026

Introduction

In large Mendix applications, understanding how different parts of the application interact is important for maintainability, debugging, and identifying the impact of changes. One of the most important tools for this is the Call Hierarchy tree view, which shows how documents such as pages, microflows, and nanoflows are interconnected.

This feature helps you understand dependencies and app connections. For example, what microflows are triggered from this page? Which pages call this nanoflow? If you change this microflow, what is affected?

The Call Hierarchy pane consists of:

  • A switch button to toggle between incoming and outgoing calls
  • A collapse-all button
  • A tree view that visualizes the call hierarchy for the currently-selected document

The Call Hierarchy tree visualizes the full call path in two directions: Incoming calls and Outgoing calls. This allows you to see where the selected document is used throughout the app (Incoming calls) and which other documents it depends on (Outgoing calls).

Call Hierarchy Pane

Show Call Hierarchy

You can visualize the Call Hierarchy by right-clicking a document from the App Explorer or from within the document editor, then selecting Show call hierarchy.

The data is calculated in the background and displayed in a tree view with the first level of the tree expanded. Deeper levels are lazy-loaded on expansion, which helps maintain performance in large projects.

Interacting with the Call Hierarchy Pane

Use the switch button in the pane to toggle between Incoming calls and Outgoing calls.

  • Incoming calls – shows the full path of where the currently-selected document is called from elsewhere in the app
  • Outgoing calls – shows the full path of documents that are called by the currently-selected document

Supported Document Types

When you select Show call hierarchy, the document is analyzed to identify its interactions with other documents.

  • For Incoming calls, the pane shows the call hierarchy for most common identifiable document types, including pages, microflows, nanoflows, JavaScript actions, and Java actions
  • For Outgoing calls, the pane shows the call hierarchy for pages, microflows, nanoflows, and rules