Writing on Tablets Tech stuff from @yeltzland

Fixed an issue using WkWebView when session cookies were intermittently dropped

This bug took about 2 years to fix!

Fingers crossed, but I think I’ve finally fixed an irritating issue in my Yeltzland iOS app, where session cookies were being intermittently dropped in WkWebView.

This was especially painful when using the Yeltz Forum as you’d be logged out of your account every so often 😞.

The problem is (always) threading

I’ve spent ages over the years trying different solutions to see what’s happening, and as far as I can the root cause is that WkWebView actually runs on a different process than the app, which can prevent cookies being synched properly - and hence being dropped if you are unlucky.

The solution

I changed the code to use a single WKProcessPool for all web views in the app, and then instantiate each WkWebView is created using the following code:

lazy var webView: WKWebView = {
    let appDelegate = UIApplication.shared.delegate as! AppDelegate
    
    // Use a single process pool for all web views
    let webConfiguration = WKWebViewConfiguration()
    webConfiguration.processPool = appDelegate.processPool

    let webView = WKWebView(frame: .zero, 
                    configuration: webConfiguration)
    webView.navigationDelegate = self
    
    return webView
}()

This was based on a very helpful comment by LinhT_24 in the Apple Developer Forums, for which I’ll be eternally grateful.

I’ve been running this code for nearly two weeks now without being logged out from the forum, so I really hope this is fixed.

Hopefully this post might help someone else with the same problems too!

iOS

Adventures in Siri Shortcuts automation

Trying out the new Shortcuts in iOS 13 - with promising but mixed results

I’ve been looking forward to the new automation options in Siri Shortcuts in iOS 13 for a while.

Previously I’ve used a hodge-podge of IFTTT, Launch Center Pro and Shortcuts to do some of what I’ll describe below, but new trigger options opens up a whole new world of possibilities.

Everything is still a bit buggy right now (as of iOS 13.1.3), but shows a lot of promise.

Automatically enabling VPN away from home

I’ve just started using Cloudflare’s free 1.1.1.1 VPN app, which so far seems reliable, fast and a lot safer when using coffee-shop WiFi networks.

I don’t want to enable the VPN when at home (there are occasional geo-location issues when trying to stream videos), but almost always want to when not on my home network.

The 1.1.1.1 app offers actions to enable or disable the VPN, so it was trivial to write a shortcut that:

  1. Is triggered on connection to any WiFi network
  2. Checks the current WiFi network name
  3. If it is my home network, disables the 1.1.1.1 VPN
  4. If it’s any other network, enables the 1.1.1.1 VPN

This is great, as I was continually forgetting to enable/disable the VPN before - now I get a notification every time I switch networks, and tapping on it quickly switches the VPN to the state I almost certainly want.

Playing Audio

Starting up Spotify

I’ve written previously about my shortcut where I started Spotify using NFC and Launch Center Pro, so it was easy to migrate this to using the NFC triggers in Shortcuts instead.

One issue was that the NFC tags I’d bought from LCP were encoded to a LCP launching URL, so I had to purchase some new tags.

The next enhancement was to setup a trigger to run the same shortcut when my phone connects to the Bluetooth speaker in my home office. This is so much easier to use than even the NFC tag - I simply turn on the speaker, and then tap the notification to fire up Spotify and get it running.

Podcasts in Overcast

The other audio I listen to regularly are podcasts in Overcast.

Overcast does have some automation hooks, although they seem a little flaky in iOS 13. I’ve written a shortcut that asks me if I want to play either Overcast or the Spotify shortcut mentioned above from a list.

I have 2 triggers to run this combined shortcut:

  • When I connect my Bluetooth headphones
  • An NFC tag in my car

Showing my Shopping List

I’ve previously built a completely over-engineered shopping system based around Todoist, IFTTT location triggers, IFTTT voice integration and an AWS Lambda function!

This worked pretty well, and basically location triggers in the IFTTT iOS app called a script which read my Todoist Shopping List when I’m near the supermarkets in Hexham, and sent an alert if there was anything I needed.

I’ve moved the location trigger in Shortcuts, but also I’m experimenting in going all-in with the built-in Reminders app, and not using Todoist any more.

This means all of the shopping list logic can be done on-device (which makes it a bit more reliable), and it’s also easy to share the list with my family.

The integration with my multitude of Amazon Echos and Google Assistants also needed a couple of custom IFTTT applets, but they were very simple to write.

It’s all a bit less Heath Robinson now, but works just as well.

Enhancements/Missing Features

I’m pretty happy with where my automation sare so far, but there’s definitely room for improvement.

First of all, the triggers - in particular the location ones - seem very flaky. Shortcuts itself seems a bit hit and miss at times, and my guess is that if any script has had problems, the app somehow hangs/is blocked, which stops the location triggers firing.

Next, it would be great if more types of triggers could run automatically rather than needing you to tap on a notification. I know Apple are very strong on privacy, but there should be a way to let me accept the “risks” and let more shortcuts be able to be triggered without needing my intervention.

Finally, there is no integration yet with the Apple Watch. I believe some Watch integration may be coming in iOS 13.2, but it would be great to be able to both start shortcuts from the watch as well run them automatically based on triggers. For example, I’d like to be prompted to start a workout as soon as I leave my house, rather than wait for the automatic “after 10 minutes walking” feature to sometimes kick in.

Summary

Just implementing these three automations has been great, and shows of the power of Shortcuts to extend the functionality of my expensive devices in truly useful ways.

If the automation system was a bit less buggy, and a bit less restrictive on needing so much user intervention, it would be truly fantastic.

Hopefully this will be coming soon! 🤞

Shortcuts

Privacy Policy Update

An update to an earlier post - removing Crashlytics and Fabric from my apps

Last year I wrote about my Privacy Policy, outlining the approach I take on my mobile apps, and trying to justify the trade-offs I’m making.

This is a follow-up on what’s changed in the mean time.

Removing Crashlytics and Fabric

I’ve been trying to remove 3rd party code from my apps as much as possible.

This is a really more of a practical concern - fewer dependencies makes it easier to change the code/keep up to date on OS changes/be agile - than privacy worries (not really knowing what 3rd party libraries are actually doing).

Therefore I decided to remove Crashlytics and Fabric from my own apps.

Both Apple and Google offer built-in basic analytics and crash reporting via the App Store Connect and Play Store servers respectively. I realised for my own apps, this is perfectly sufficient for what I need.

All I really care about is finding out about crashes or issues, plus every so often knowing the breakdown of OS versions my users have so as to plan when I can drop support for older devices.

This isn’t an anti-Google stance, as I’m still using Firebase and Google Mobile Ads. It’s just why give my user’s data away any more than I need to?

Summary

Your mileage may vary, and I’m not sure I’d advise this approach for all my clients, but I’m happy this will work well for me and my users.

Privacy

A Shortcut for sharing Live Photos

Replacing some average iOS apps for converting Live Photos with a simple Shortcut

Here's one I made earlier

I’ve been searching for an easy way to share iOS Live Photos on social media for a while, and have tried a whole bunch of frankly pretty average apps without being very happy with any of them.

Last week Jason Kottke shared on Twitter a shortcut that could convert a Live Photo into a video, which looked close to what I wanted. I’d never considered I could write my own converter before!

Below is a screenshot of my version. This one will convert a Live Photo into a looping animated GIF. A little trick I also learnt was if you use the “Quick Look” block at the end, you get a preview of how the GIF looks, as well as a share button from where you can share or save it as appropriate.

The image of Seljalandsfoss from last year’s trip to Iceland above was made using the script - and I’m very happy with the results!

Live Photos shortcut

Shortcuts Live Photos

Getting Daily Alerts for MLB Condensed Games

Keep up to date on the travails of the Mets without needing an MLB TV subscription

Citi Field

30 years ago I spent a couple of summers working in New Jersey, and got drawn into the crazy world of New York Mets baseball.

Back then, keeping in touch when back home meant scouring the International Herald Tribune for any baseball news, but for the last decade I’ve been a subscriber to MLB TV which has been fantastic.

When considering renewing this year’s subscription, I realised I hardly watch any live games any more. Most games are played in the evening US Eastern Time or later, so what I generally do is wait until the next morning and try to watch the condensed game - around 5 minutes of “Match Of The Day” style highlights - without knowing the score.

Accessing MLB Condensed Games for free

MLB are a lot less precious with their highlights packages than the Premier League (surprise, surprise!), and make a lot of content available for free on both YouTube and within the MLB TV app for free.

However within the MLB TV app you can’t get notifications for when new condensed games are available without a paid subscription (which is fair enough!), and it’s really hard to check when a the video is ready without finding out the score, or some information about the game via the other videos already published.

However, the excellent Baseball Theater had figured out that the configuration for the mobile apps is held in the open, so that gave me the idea of hacking together a similar solution to send alerts as soon as there is a new condensed game is ready for viewing.

My MLB Condensed Games alert system

It’s all a bit Heath-Robinson, but my system works as below. Note the code is all avaialble on GitHub, and the below is copied from the readme.md of the repo:

There are 2 main entry points - designed to be run from AWS Lambda:

  1. lambdaCondensedGame,js - Checks whether a condensed game stream is available for a given team on a given day
  2. lambdaMonitor.js - Will see if a condensed game has been added, and if so sends a Slack message saying a new game is ready, plus a link to the stream

Condensed Game function

This function reads from the POSTed JSON formatted like:

{
	gameDate: "2019-04-26",
	team: "nym"
}

You must also send a HTTP header of MLBAPIRequest with a value set as an environment variable of the same name.

This will then:

  1. Build URL like http://gd2.mlb.com/components/game/mlb/year_2018/month_06/day_26/master_scoreboard.xml (using the incoming date)
  2. Look for <game> node where home_file_code=”nym” or away_file_code=”nym” (using the incoming team)
  3. Pick up game_pk attribute to get the URL e.g. “https://statsapi.mlb.com/api/v1/game/530594/content?language=en”
  4. Find in the media.epgAlternate nodes the “Extended Highlights” section, and then find the item that is the condensed game video (if it exists)
  5. Pick the correct URL node - the video that has a value that ends in .mp4

Assuming that a condensed game is found, the function then returns JSON like:

{
	"opponent": "pit",
	"date": "2019-04-26",
	"url": "http://mediadownloads.mlb.com/mlbam/mp4/2018/06/27/2202032583/1530076464641/asset_1200K.mp4",
	"mediaType": "Extended Highlights" 
}

Note:

  • The opponent attribute can null if no game has been found
  • The url attribute can null if no condensed game stream has been found for the game
  • The mediaType attribute can null or “Extended Highlights” (I experimented with also getting the “Recap” for a while)

Configuration - Environment variables

  • MLBAPIRequest: The value to be sent in the header of any request

Monitoring function

This function saves the last found game data in an S3 bucket, and then is designed to run on a schedule to do the following:

  • Looks at date in saved game data JSON from the last successful run
  • If date is today, we’re done (we don’t cope with double-headers yet!)
  • Otherwise, call the condensed game function for either yesterday or today (if the last game was yesterday), and if the result has a url attribute
    • Save the latest game data JSON to S3
    • Call Slack sending the url attribute in a mesage
    • Call an IFTTT web hook that sends an iOS notification, clicking on which opens the viedo URL

You can setup a schedule in Cloudwatch to run every N minutes.

Configuration - Environment variables

  • S3ACCESSKEYID: Access Key for the S3 bucket to save game data
  • S3DATABUCKET: Name of the S3 bucket to save game data
  • S3DATAFILE: Name of the file to save game data in
  • S3SECRETACCESSKEY: Access Secret for the S3 bucket to save game data
  • SLACK_WEBHOOK_URL: URL of the webhook to send the Slack message to
  • TEAM: Team abbreviation to monitor e.g. nym
  • IFTTT_EVENT_NAME: Name of the IFTTT event to send the notification call to
  • IFTTT_MAKER_KEY: Name of the IFTTT maker key to enable IFTTT calls

Summary

Everything is working really well so far, and I’m getting exactly what I need. Very happy! I may still subscribe to MLB TV later in the season if I’m missing the weekend live games - or indeed if the Mets get in a playoff race - but for now I can keep wtaching the highlights without it.

The MLB “API” was a bit in flux for the first few weeks of the season. It’s not a public API so that’s to be expected, but hopefully it will be stable for a while now.

I also built an iOS Shortcut to call the API directly, so if for some reason the video URL changed, or I missed/deleted the notification by accident.

If you want to set something similar up for yourself and if the GitHub instructions aren’t clear, let me know and I’ll try to help you out!

MLB AWS Lambda