priority of client script and ui policy

[aditya2byte]

ui policy        setvisible=true

client script   setVisible=false

Clien script over rides ui policy

but for  setmandatory and set readonly ui policy over rides client script 

so why in first case ,client script over rides ui policy

[aditya2byte]

ok

[Bhuvan]

@aditya2byte 

Did you get a chance to review this ?

If my response helped to answer your query, please mark it helpful & accept the solution.

Thanks,

Bhuvan

[Rafael Batistot]

hi @aditya2byte 

Visibility → Client Script wins (because it manipulates the DOM directly).

Mandatory/Read-only → UI Policy wins (because ServiceNow enforces them after scripts to ensure compliance with rules).

[aditya2byte]

Ok, Thank You

 Warm regards,

Aditya HUblikar

[Ajay_Chavan · Accepted solution]

Why Client Script Overrides UI Policy for setVisible:

Timing: Client scripts run after UI policies
Last Action Wins: Whatever executes last determines final visibility
No Form Validation: Visibility is just DOM manipulation


Why UI Policy Overrides Client Script for setMandatory/setReadonly:

Form Engine Control: UI Policy engine has higher precedence for form validation
Built-in Protection: ServiceNow protects mandatory/readonly settings at form level
Validation Priority: Form validation rules override client-side changes

Execution Order:
1. Form Loads
2. UI Policies Execute  
3. Client Scripts Execute (onLoad)
4. Field Changes → UI Policies → Client Scripts (onChange)

Summary:
setVisible: Pure DOM manipulation → Last script wins (Client Script)
setMandatory/setReadonly: Form validation → UI Policy precedence (System protection)
Key Point: ServiceNow treats visibility as presentation but mandatory/readonly as form validation rules with different priority systems.