Niagara User-Based Visibility Conditions

Topic: Niagara Graphics, User Permissions
Difficulty: Intermediate

Overview

Make graphic elements visible or hidden based on the currently logged-in user. Control UI element visibility by user role.

The Goal

Make a Hyperlink label visible only when user is "admin" and invisible when user is "oper" (operator).

Solution: Session-Based Visibility

Use session variables to determine the current user and conditionally show/hide elements.

Method 1: Role-Based Visibility (Recommended)

Check user's role instead of username:

<label text="Admin Settings">
  <visible binding="session:|user/role" 
           visibleValues="admin,superuser"/>
</label>

Method 2: Username Check

For specific user visibility:

<container>
  <visible>
    <equals>
      <binding ord="session:|user"/>
      <value>admin</value>
    </equals>
  </visible>
  <hyperlink text="Admin Only Link" ord="..."/>
</container>

Session Variables

Access current session info:

• session:|user - Username
• session:|user/role - User's role
• session:|user/displayName - Display name

PX Visibility Logic

<pxContainer>
  <!-- Visible only to admin -->
  <hyperlink text="System Settings" ord="/admin">
    <pxVisible>
      <pxEquals>
        <pxBinding ord="session:|user"/>
        <pxString value="admin"/>
      </pxEquals>
    </pxVisible>
  </hyperlink>
  
  <!-- Visible to operators -->
  <hyperlink text="Operations" ord="/ops">
    <pxVisible>
      <pxEquals>
        <pxBinding ord="session:|user/role"/>
        <pxString value="operator"/>
      </pxEquals>
    </pxVisible>
  </hyperlink>
</pxContainer>

Best Practices

• Use roles instead of usernames
• Combine with server-side security
• Don't rely solely on visibility for security
• Test with different user accounts

Related Topics

• Categories, Roles & Users
• Basic PX Graphics
• Create Relativised Objects in Niagara 4