checkAccess

[ Function ]

public static checkAccess(
   control: TcHmi.Controls.System.baseTcHmiControl, 
   requestedAccessright: string
): boolean | null;

Checks an access right of a control. All controls provide the operate and observe rights. Controls can define additional rights names and respond accordingly. Rights are always assigned to groups.

If a right is not explicitly defined on a control itself, its parent control is checked. Therefore, a check is only possible after attaching.

Possible situations:

• In Engineering within Visual Studio a right is always granted.
• If a server does not have a password query, a right is always granted.
• If a control is not attached, no decision is possible.
• If a group of the current user permits the right, the right is granted.
• If no group of the current user permits the right and one group denies the right, the right is denied.
• If no group of the current user permits or denies the right, the parent control is checked.
• If no parent control has explicitly set this right, the standard right applies (operate and observe have "permit" as default).
• Other borderline cases are explained under: Configuring control access

Parameter

Return value

Available from 1.8

Sample - JavaScript

A right is to be checked in a separate event handler. This must be added in Description.json, otherwise the right cannot be configured in Visual Studio.

var myDiv = $('<div>Hello World!</div>');
myDiv.on('click', function(evt) {
   if(TcHmi.Access.checkAccess(myControl, 'doFancyStuff') !== true){
      return; // current user has no right to do this
   }
   // fancy stuff
});
myControl.getElement().append(myDiv);