Displaying i18n text on HTML-button depending on condition Aurelia -

hi trying dynamically change text depending on boolean. im using aurelia i18n, 1 solution have method returns want. have in html, because think clearer see text button have depending on bool in html code. looks now:

<button>${account.changed ? '_cancel' | t : '_close' | t } </button> 

this have tried:

<button>${account.changed ? ('_cancel' | t) : ('_close' | t) } </button> <button>${account.changed ? ${'_cancel' | t} : ${'_close' | t} } </button> 

any of tries ends crash:

error: parser error: conditional expression account.changed ? '_cancel'  requires 3 expressions @ column 33 in [account.changed ? '_cancel' | t : '_close' | t ] 

i have used i18n this point:

<div>${'example | t'}</div> 

never needed change text depending on condition before.

to comes here, solved doing this:

innerhtml.bind="!account.changed ? close  : cancel" 

and in .js

   this.close = this.i18n.tr('_close');    this.cancel = this.i18n.tr('_cancel'); 

i think should possible in way achive directly in html aurelia

this i'm using:

<span t="_cancel" if.bind="account.changed"></span><span t="_close" if.bind="!account.changed"></span> 

i stuck on while , best way found it.