Thank you for very interesting and usefull article. I tryed to recreate your example and I got en error
ERROR TypeError: Cannot read property ‘nativeElement’ of undefined
at TooltipComponent.webpackJsonp…/../../../../src/app/components/10-tooltips/tooltip.component.ts.TooltipComponent.ngOnInit (tooltip.component.ts:33)
at checkAndUpdateDirectiveInline (core.es5.js:10836)
at checkAndUpdateNodeInline (core.es5.js:12332)
at checkAndUpdateNode (core.es5.js:12271)
at debugCheckAndUpdateNode (core.es5.js:13132)
at debugCheckDirectivesFn (core.es5.js:13073)
at Object.eval [as updateDirectives] (TooltipComponent_Host.html:1)
at Object.debugUpdateDirectives [as updateDirectives] (core.es5.js:13058)
at checkAndUpdateView (core.es5.js:12238)
at callViewAction (core.es5.js:12603)
It occurs when I move to text with tooltip, Tooltip works, but I have an erro in console. Could you help me?