A Visual Explanation of SQL Joins

I thought Ligaya Turmelle's post on SQL joins was a great primer for novice developers. Since SQL joins appear to be set-based, the use of Venn diagrams to explain them seems, at first blush, to be a natural fit. However, like the commenters to her post, I found that the Venn diagrams didn't quite match the SQL join syntax reality in my testing.

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Pattern: Riblets vs. VIPER

Engineering the architecture behind Uber's new rider app

Not being held back by our extensive codebase and previous design choices gave us the freedom where we otherwise would have made compromises. The outcome is the sleek new app you see today, which implements a new mobile architecture across both iOS and Android. Read on to learn why we felt the need to create this new architecture pattern, called Riblets, and how it helps us reach our goals.

The platforms share:

Core architectureClass namesInheritance relationships between business logic unitsHow business logic is dividedPlugin points (names, existence, structure, etc.)Reactive programming chainsUnified platform components
Each Riblet is made up of one Router, Interactor, and Builder with its Component (hence the name), and optional Presenters and Views. The Router and Interactor handle the business logic, while the Presenter and View handle the view logic.

Uber

How to link to TestFlight App in iOS

There are two things you need to do. First, check to see if TestFlight is installed. Then create a new link to your app.

NSURL *customAppURL = [NSURL URLWithString:@"itms-beta://"];
if ([[UIApplication sharedApplication] canOpenURL:customAppURL]) {

// TestFlight is installed

// Special link that includes the app's Apple ID
customAppURL = [NSURL URLWithString:@"https://beta.itunes.apple.com/v1/app/978489855"];
[[UIApplication sharedApplication] openURL:customAppURL];
}

This special https://beta.itunes.apple.com URL will be opened directly in TestFlight.

Finally, if you are using iOS 9 (or later), you need to make an addition to your Info.plist to get the canOpenURL: method to work.

If your app is linked on or after iOS 9.0, you must declare the URL schemes you want to pass to this method. Do this by using the LSApplicationQueriesSchemes array in your Xcode project’s Info.plist file. For each URL scheme you want your app to use with this method, add it …

Implementing UI tests on iOS and Android using screenshot comparison tools

Have you ever thought when writing or maintaining UI tests, there must be a better way?

Take a look at screenshot tests provided by Google Firebase and Facebook:

ios-snapshot-test-case
A "snapshot test case" takes a configured UIView or CALayer and uses the renderInContext: method to get an image snapshot of its contents. It compares this snapshot to a "reference image" stored in your source code repository and fails the test if the two images don't match.

GitHub Facebook

screenshot-tests-for-android
Testing rendering for your Android app is hard. How do you prevent visual regressions in paddings and margins and colors from creeping in?
Iterating on UI code is hard. How do you quickly verify that your layout or view changes work correctly in all configurations?

screenshot-tests-for-android can solve these problems by providing a test framework that checks for visual differences across changes.

GitHub Facebook

Google Firebase Test Lab
Test Lab lets you run Espresso, …

iOS 7 Blur Effect

Combining a strong colour with a blurred and translucent UINavigationBar in iOS 7.

// cheers to @stroughtonsmith for helping out with this one
UIColor *barColour = [UIColor colorWithRed:0.13f green:0.14f blue:0.15f alpha:1.00f];

UIView *colourView = [[UIView alloc] initWithFrame:CGRectMake(0.f, -20.f, 320.f, 64.f)];
colourView.opaque = NO;
colourView.alpha = .7f;
colourView.backgroundColor = barColour;

self.navigationBar.barTintColor = barColour;

[self.navigationBar.layer insertSublayer:colourView.layer atIndex:1];

GitHub Gist
See also
iOS7-Trans-Blur

And also
myView.backgroundColor = [UIColor clearColor];
UIToolbar* bgToolbar = [[UIToolbar alloc] initWithFrame:myView.frame];
bgToolbar.barStyle = UIBarStyleDefault;
[myView.superview insertSubview:bgToolbar belowSubview:myView];

Why bother replicating the effect? Just draw a UIToolbar behind your view.
StackOverflow

Alpha Apps vs. App Unbundling

Alpha Apps
Die chinesische App WeChat geht noch weiter: Neben einem Messenger, vergleichbar mit WhatsApp, bietet sie einen Lieferdienst à la Lieferando, die Möglichkeit etwa das eigene Konto zu checken (wie sonst bei der Bank-App) und gleichzeitig die Chance etwa Promis zu folgen, wie es Twitter bietet.

Solche Alpha-Apps können dadurch verschiedene Aspekte und Möglichkeiten des Internets verbinden und werden so zum idealen Zugangsportal zum Netz – so wie traditionell der Browser am Computer. Den Tod des Browsers bedeutet das aber noch lange nicht.

Der Browser ist tot, es lebe der Browser!
Wirtschafts Woche

App Unbundling Unbundling steht für das Unterteilen von Apps oder verschiedener Funktionen in mehrere, eigenständige Applikationen.

Aber nicht jede Unbundling Aktion wird positiv von Usern aufgenommen. Facebook Messenger erhielt hunderte miese Bewertungen in den App Stores, denn viele User fühlen sich von Facebook grundlos gezwungen eine zusätzliche App herunterzuladen. Das Fazit: was…

Apps vs. Web

Eines scheint klar: Mobil büßt er gegenüber den Softwareprogrammen aus dem App-Store Nutzer ein. „Mittlerweile spielen Apps die wichtigste Rolle für den User – oder sie werden sie zumindest sehr bald spielen“, sagt Jan Wolter, Geschäftsführer von Applause EU.

Apps bieten also im Gegensatz zum Browser Schnelligkeit gepaart mit Einfachheit und Bequemlichkeit. Sie öffnen zwar nicht die Welt ins gesamte World Wide Web, wie es der Browser kann, aber sie öffnen die Welt, die man möchte, wenn man ihr Icon auf dem Tablet anklickt.

Die chinesische App WeChat geht noch weiter: Neben einem Messenger, vergleichbar mit WhatsApp, bietet sie einen Lieferdienst à la Lieferando, die Möglichkeit etwa das eigene Konto zu checken (wie sonst bei der Bank-App) und gleichzeitig die Chance etwa Promis zu folgen, wie es Twitter bietet.

Solche Alpha-Apps können dadurch verschiedene Aspekte und Möglichkeiten des Internets verbinden und werden so zum idealen Zugangsportal zum Netz – so wie traditionell der Brows…

Why Core ML will not work for your app (most likely)

While the buzz around newly released Apple framework is loud, I want to explain several things, that may not be obvious for those who are new to machine learning (ML).
Core ML is not a machine learning framework.Core ML supports only two types of ML.If your models are proprietary or contain sensitive information, you can’t use CoreML.Core ML doesn’t solve the privacy concerns.Core ML doesn’t compress models.Core ML is not the only way to do machine learning on iOS.
Learn Machine Learning, not Core ML.
Impervious Invisibility

Google’s AutoML lets you train custom machine learning models without having to code
TechCrunch

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