Is visible: {{visible}}
button (always visible)
button (p *ngIf="visible")
button (button *ngIf="visible")
button (p *ngIf="!visible")
button (button *ngIf="!visible")
a (always visible)
a (p *ngIf="visible")
a (a *ngIf="visible")
a (p *ngIf="!visible")
a (a *ngIf="!visible")
NO ion-button
a (*ngFor {{i}})