Conditionally hide and show button, change button label/text

Hi. This is the first time that I try to get in touch with the Ionic community. Ionic is pretty new to me, but I am still exited. There are some things that should be simple, but I have not found a smooth solution. I need a way to hide and show a button in the content area conditionally. The button should be hidden by default, but be visible when a function in a controller has run. In my example an “Upload Video” button should show up when a video is recorded or picked from the photo gallery. I also then would like the label/text on my: “Choose a Video” button to change to: Choose another Video from within the controller.

you can change button caption like this: <button class="button button-stable" {{caption}} </button>.

For hidding and showing you can use ng-if

Thank you so very much for a quick answer Adamxyz. It helped a lot.
Change button caption(button label/text):
index.html:
<button class="button button-block button-positive icon-left ion-ios-film" ng-click="showOptions()">{{caption}}</button>
app.js:
$scope.caption = "Choose Video";
.controller:
$scope.caption = "Choose New Video";

When is comes to ng-if it can be studied at:
http://school.codecraftpro.com/courses/ionic-from-web-to-mobile/lectures/361656