Need Help on UIApplication.endBackgroundRask

I have created an app that stores airplane inspection and maintenance history, including any photographs and other documentation. In a view controller, a user selects a maintenance requirement to view the history which results in a collection view being loaded displaying all the history by date, in collection view cells. If the user taps on a collection view cell, code is called up to go and get the image data and display it in a tableview format.

However, I don’t think I am retrieving the information from Cloud Firestore properly as I am running into a number of issues that I have spent many hours over the past few weeks trying to resolve.

I have gone back through the lessons and googled solutions and I have included adding completion blocks and running the code on an asynchronous thread using

I obviously don’t understand something basic based on the problems I am seeing and I am hoping that someone on here could give me a hand by reviewing my code.

Problem 1:

The first time the user taps on the collection view cell, a blank cell comes up and sometimes it takes several taps before the user is taken to a tableview to view the images. This tells me that the image data hasn’t finished loading before the table view is loaded. I ran into this problem before on another view controller and was able to resolve it with reloading the view in the main thread. But that hasn’t helped with this problem.

Problem 2:

I noticed that sometimes the following error is displayed after the images are displayed:

[BackgroundTask] Background Task 20 (“”), was created over 30 seconds ago. In applications running in the background, this creates a risk of termination. Remember to call UIApplication.endBackgroundTask(_:slight_smile: for your task in a timely manner to avoid this.

If someone is willing to review my code I would really appreciate any advice they can give me on how to properly download and display images. Here is the link:

The first page of code is the view controller that displays the collection view cells with the image history. It includes a “getImage function” that is called up when the collection view cell is tapped.