Web Service

I have 2 tab say Tab-A and Tab-B.
Tab-A uses a back-end web service to load data in a List. The problem is when ever I switch to Tab-A from Tab-B this web service is called, resulting in fetching the same data again and again. What I need is this should load the data for the first time and persists locally;reload happen only on pull-to-refresh event. How can I achieve this in ionic? any guide or samples? Please advice

Idea: You could save the time the last call was made and only update on the tab switch if it was > a certain period of time. The pull to refresh could pass a param that forces the data to refresh, negating the time the data was updated.