Alert is an AngularJS-version of bootstrap's alert.
This directive can be used to generate alerts from the dynamic model data (using the ng-repeat directive);
The presence of the close attribute determines if a close button is displayed.
The optional dismiss-on-timeout attribute takes the number of milliseconds that specify timeout duration, after which the alert will be closed.
The optional template-url attribute allows the user to override the default template with a custom template on an instance by instance basis