Author Archives: Mark Durham

iOS Networking with Swift: Strongly Discouraged, but it Works!

At first it appears that the authentication flow has been significantly changed away from the flow presented in Lesson 5: Authentication Requests, because basically it has. Instead of entering in your TMDb credentials (username and password) into the app (where presumably the app could surreptitiously co-opt them), TMDb wants app developers to let TMDb authenticate users directly through their (TMDb’s) website. You can do this using a segue to an authentication view controller with a web view and a web view delegate, but that is not as spiffy as handling login in your own login view.

But while implementing this new flow, I stumbled across the following URL request:

GET/authentication/token/validate_with_login

It is listed as strongly discouraged, but by golly that is the request that this course is looking to use in the loginWithToken() method, and it still works! I might go back and finish the new authentication flow, since I actually have it fully implemented, but for now I’m sticking with old school. If you want to go old school too, here is the link to the appropriate documentation: https://developers.themoviedb.org/3/authentication/validate-request-token

Also, the instructor’s notes in step 18 of Lesson 5 include example code on how to use validate-request-token.

iOS Networking with Swift: Lesson 5: Authenticating Requests

If you are attempting the quiz “Which Methods to Use?” in “Lesson 5: Authenticating Requests” (aka “Lesson 3”), don’t bother. The API has changed since the quiz was written and finding the old API is darn near impossible. I eventually had to get on “The Movie Database Support” website (after a long, round-about search of the internet) and find a support request that just happened to mention the genres method. For completists, here are the methods old and new:

Old (Quiz Answers)

/genre/{id}/movies
/account/{id}/favorite/movies
/account/{id}/favorite

New (For Actual Use)

/genre/movie/list
/account/{account_id}/favorite/movies
/account/{account_id}/favorite

iOS Networking with Swift: Lesson 4: Chaining Asynchronous Requests

In “Lesson 4: Chaining Asynchronous Requests” (or “Lesson 2” in the video; now our count is off by two!), there is a ridiculous claim that you cannot retrieve any photos beyond 4000 (or possibly less). That is pure nonsense!

Here is what the Flickr API is trying to tell you. Flickr is only going to return one page of results. If you do not ask for a particular page, you are going to get the default page (which is Page 1).

That page is going to have between zero and (the current maximum of) 500 results. (See `per_page` in the Flickr API documentation.) I believe at one time you could request up to 4000 results per page (hence the warning “Please note that Flickr will return at most the first 4,000 results for any given search query”), but that has since been reduced to 500. This does not limit you to only the first 500 (or even 4000) results though!

You can certainly request page 41 and receive valid results that are beyond the first 40 pages of 100 results each. I know this to be true, because my FlickrFinder app can and has done just that.

Is this because asking for a specific page is “a more specific query”? Yes, it is.

Maybe Flickr’s API was broken when the video for this lesson was made, but now it isn’t, so all of the discussion about 4000 and the limitations of retrieving photos is now obsolete. This line of code:

let pageLimit = min(totalPages, 40)

is completely unnecessary. Just use totalPages as the pageLimit.

iOS Networking with Swift: Lesson 3: Problem Set: JSON Parsing

These are good exercises, worth doing, with the following caveats.

For the Animals Exercise, I found it completely unnecessary to write any code. I just looked at the raw JSON file and answered the questions using that. Thankfully, the next exercise data set was both large enough and complicated enough that writing code appears to be the quicker solution.

For the Hearthstone Exercise, I could not successfully get the hearthstone.playground (or the hearthstone-solution.playground for that matter) to execute more than once. Any changes to the code would send Xcode off into NeverNeverLand until I completely quit Xcode and restarted the playground. (This is Xcode version 8.3.2, by the way.)

My solution to the problem was two-fold, but perhaps only one of these is necessary:

  1. Set the playground to “Manually Run”. By default, the playground will automatically run. To change it to only run when you want it to run, long-click the square (if the playground is currently running) or the right-facing “play” triangle (if the playground is paused or “Ready”) at the bottom-left of the Editor area and select “Manually Run”. Now, when you want the playground to run, click the right-facing “play” triangle.
  2. Rebuild the playground from scratch. In particular, I removed all forced unwrapping (‘!’) and references to NSDictionary. Furthermore, there is no need to pass the parsedHearthstoneJSON variable into the parseJSONAsDictionary() function. (You will note that the argument dictionary is never referenced anywhere inside the function.) Although putting the parsing into a function is a good idea for app code, it is unnecessary here in this playground.

iOS Networking with Swift: Lesson 0 and Lesson 1

First off, I wouldn’t mind the course designer getting cute and starting with Lesson 0 instead of Lesson 1 if the Udacity system supported it. Unfortunately, Udacity does not. Therefore, Lesson 0 is listed as “Lesson 1” in the Udacity menu system, and each Lesson n is listed as Lesson n+1. Although not very confusing, it is still pointlessly confusing.

Secondly, unlike the previous course, the menu system only lists one lesson at a time. This would not be quite so annoying if I had not already experienced the benefits of being able to look back and look ahead without jumping all the way back to the course roadmap.

I like the presenters and, for the most part, the way the material is presented. In Lesson 1: Using Web Services and APIs (I am using their lesson numbers, not Udacity’s), there is still way too much of “Here, look at this code, copy it into your project, and then run it.”

Lesson 0: Making a Network Request was entertaining and informative enough. As it has been some time since I viewed the lesson and there was not much new to me within it, that analysis will have to suffice. On to Lesson 1.

I both like and dislike the use of Flikr for this app. I like that we are using a real, honest-to-goodness commercial API that we might want to actually use for some future app. I dislike the confusion of “photo-this” and “photo-that” though, and the presenter even acknowledges the problem. They chose fairly well however because that API, and particularly the JSON data it returns, show considerable depth and expose a variety of JSON object types.

Please note that even the new code in this lesson is slightly out-of-date. Nothing too difficult to handle though. Xcode’s auto-fix will generally guide you in the right direction.

UIKit Fundamentals: Bits and Pieces

This post probably concludes my look at the UIKit Fundamentals course. I am still finishing up MemeMe 2.0, but I doubt I will have anything to add after completing it. There were two additional bits and pieces I wanted to address though.

The first is a line of code that you may or may not encounter in step6.1-bondVillains-noTabs. In that code is a left-over call (from an Xcode 6 template, I believe) to registerClass(_, forCellWithReuseIdentifier:). If you fail to delete that line of code, any attempt at creating a cell in the storyboard will be for naught. The line has been deleted from subsequent iterations of the Bond Villains app (steps 6.2 through 6.4), so it will only cause you grief if you try to add a cell in the storyboard in step 6.1 (as I did).

The second issue is the complete lack of a textual rubric or outline or list of requirements or checklist for the MemeMe 2.0 project near the end of this lesson. There were checklists for other, less challenging apps in this course; why not for the biggest, most complex app? Instead, I have to go back through the videos and try and find every last little requirement and make my own checklist. That may be an important skill to have, but I know this omission was not an intentional teaching device.  I just can’t understand this oversight.

UIKit Fundamentals: MemeMe 2.0

I am through with the online content of this final lesson, and therefore the course, but I still need to complete the project. I have to say that they dropped the ball a bit at the end here, mixing up tab controllers and collection view controllers was not such a good idea. There is not much to implementing tab controllers, but it is made much more confusing than it needs to be because of introducing collection view controllers at the same time.

What is worse, the introduction of collection view controllers is haphazard at best. They use things before they present and explain them, and then they explain other things twice in a row. Explaining things twice in a row is in and of itself is not so bad — there is something positive to be said for repetition — but considered alongside the lack of explaining other things makes it clear that this final lesson was rushed and poorly planned-out.

I will try to wrap things up after I finish the final project.

UIKit Fundamentals: Navigation (continued)

Oh, thank goodness they return to the Make Your Own Adventure App and do it the right way, or at least a better way. I am so relieved that I am writing this post even though I have yet to complete the lesson.

Although we have been left to do a lot of coding on our own here in this unit, I don’t feel like we were thrown into the deep end this time. The written prompts have been fairly clear and helpful. (They did leave out the label for the Bond Villains app, but I hope most people can fill in those gaps themselves.)

UIKit Fundamentals: Navigation

Make it stop! Aaaaaagh!

I’m only part way into the Navigation lesson, but my eyes are bleeding at the copy/paste implementation of the Make Your Own Adventure app. There has to be a better way of demonstrating how to use Navigation Controllers — one that does not encourage people to use this insidious, hideous pattern of abuse!

UIKit Fundamentals: Table Views

I can’t say there was much that surprised me about this lesson, except perhaps that we added a table view into a custom UIViewController, rather than start with a UITableViewController. That is understandable though, because the UITableViewController is ultimately more limited. Given the number of times I have forgotten to hook up a table view delegate and table view data source to my table view and wondered just what was going on, it is probably best to start off where you absolutely have to hook those up for yourself. (In case you don’t know, if you use a UITableViewController in a storyboard, it automatically hooks those up for you.)