While I utilized the endpoints given on the URL referenced in the PDF, I also created a custom url constructor to get data by date, not just canned hour, day, week, and month information.
I used delegation to communicate between the data manager class and the view controllers. I created a custom webview to view details about the quake from the USGS' website. That view uses KVO to update a progress bar to know how the page load is going with the WKWebView.
Data that is retrieved from USGS is persisted locally to minimize network calls. The current date will always download from USGS, but prior dates are first checked to see if they exist in the managed object context before they are saved to ensure no duplicate data is persisted.
Additionally, data is displayed in a UITableView utilizing NSFetchedResultsController.
I utiliized Alamofire for networking. Additionally, I used Apple's URL constuctors and the Codable protocol to parse the JSON returns.
I enabled NSAllowsArbitraryLoads in the NSAppTransportSecurity dictionary in info.plist, but in a production app you'd certainly want to clamp down on internet access a bit.
For the QuakeDataViewController, I utilized FSCalendar, an Objective-C framework, It is IBDesignable, so configuration is a breeze. The only downside with it is it doesn't like to be put in other UIViews, just UIViewControllers. To get around that limitation, I created a UIView on a standalone View Controller and made the content view black with 20% alpha or so. This way, the code can be reused.
I utilized WARangeSlider, which is a two-handled slider on the FilterView on the "yet-to-be-implemented" UIView class I'm creating to filter data from Core Data to update the user interface.
I utilized StackOverflow to obtain the most recent version of setting a timeout for Alamofire. I also used StackOverflow to determine how to save Core Data on a background thread.
I utilized dionc/MapKitExtensions.swift extension to compute the center from an array of CLLocation2DCoordinates.
I utilized Core Data to persist data from USGS. When returns come back from USGS, before the data is imported into Core Data, I did a fetch request for unique identifiers that are already persisted. Then, I use Set to do a comparison between the two to determine which records should be persisted in Core Data.
I initially envisioned two view controllers utilizing a singleton class, but I encountered flaky behavior, so I refactored to a non-singleton class with a couple of initializers. One initializer takes date parameters andn another one just runs the canned USGS URLs. Prior to working on this project, I had never found it necessary to run core data on a background thread, so I finally got to use a private queue to run it on a background thread.
I used Inkscape to create the vector icons in the app. Some of them are inspired by icons found at Icons8.
I created a webview that displays the USGS webpage for the earthquakes. The webview utilizes KVO to monitor page load progress.
Press the UISegmentedControl on the Quake tab to retrieve quake data for minutes, hours, week, and month. The calendar icon opens up a view controller that enables you to select dates to search. Multiple selection is only available for contiguous dates. You probably don't want to import more than 30 days at a time.