Expression Binding in Standard List Item: Icon Change

Dear Experts,

I am attempting to use the expression binding to change the icon of list items based on the text supplied to a standard list item as below:

<StandardListItem        title = "{userlist>username}"        icon = "{= ${userlist>username}.toUpperCase()==='ALL' ? {i18n>UserPath} : {i18n>UserPath}}"        iconDensityAware="false"        iconInset="false"        type = "Navigation"        press= "onItemSelect"        />

The username field has to be evaluated and based on the same icon has to be changed.

Here

UserPath = sap-icon://customer

I tried different expressions as below:

icon = "{= ${userlist>username}.toUpperCase()==='ALL' ? 'sap-icon://customer' : {i18n>UserPath}}"
 icon = "{= ${userlist>username}.toUpperCase()==='ALL' ? ${i18n>UserPath} : ${i18n>UserPath}}"

etc....

The icon is not displayed at all.

Please assist.

Thanks in advance.