angular material design animation from list to card - css-transitions

Question

If I have a list of "simple" cards that is rendered using ng-repeat,
what would be the recommended way to do a transition to a detailed view of one of those cards?
Does such a transition imply that the same HTML / DOM element needs to stay on screen and its content needs to change?
Does such a transition imply that the collection upon which ng-repeat is based needs to change so that it only includes that single item that we are transitioning to or does the rendering of the rest of the items should use some version of ng-if="item.id=focused_item_id"?

Answer 1

It doesn't need to be the same DOM element, and arguably shouldn't be. Animating width or height will cause repaints/reflows and will greatly hinder performance.
You could use ng-animate (https://docs.angularjs.org/api/ngAnimate) with a single detail element that gets populated with the relevant details from whatever object was clicked.
Something like this:
HTML
<div class="item" ng-repeat="el in elems track by $index" ng-click="getDetails(el)">
<div>Summary</div>
</div>
<div class="details" ng-if="showDetails">
<div>Details for {{currentItem}}</div>
</div>
CSS
.details {
position: fixed;
width: 100%;
transition: all 1s ease-out;
}
.details.ng-enter,
.details.ng-leave-active {
opacity: 0;
transform: scale(0.8);
}
.details.ng-enter-active,
.details.ng-leave {
opacity: 1;
transform: scale(1);
}
So getDetails() would do something like set $scope.showDetails = true; and set $scope.currentItem = el; Then you could have a close button that resets those two scope variables and destroys the detail element.
Hope that helps!

Answer 2

I have done what you are describing using CSS transitions on the DOM element in question. I have a list of elements, and when you click on one, the backing object has an 'expand' property set to true, which makes extra content visible and adjusts the size.
HTML
<div ng-repeat="el in elems" ng-class="{expand: el.expand}" class="element">
<div ng-click="el.expand = !el.expand">Summary</div>
<div ng-if="el.expand">Details</div>
</div>
CSS
div.element {
transition: 0.5s linear all;
height: 200px;
}
div.element.expand {
height: 500px;
}
Try clicking on 'Summary 1' or 'Summary 2' in the plunkr
https://plnkr.co/cDkuNjTbE83L5bDJccsJ