Tag Archives: programming

How to Place Your App Inventor Apps in the Google Play Store

An all new tutorial on this subject is available here as of May 2016! There is still some great information below – read both!

Apps you create in App Inventor may be added to the Google Play Store.

The process is not difficult but there are many steps to the process and you will need to create some graphic images to illustrate and promote your app in the store.

Summary of the Steps

  • Set your app’s VersionCode and VersionName.
  • Apply for a Google Developer account (one time fee of US $25 after which you can upload an unlimited number of apps, forever).
  • Create at least two and up to 8 screenshots of your app for display in the store’s app listing.
  • Create a “feature graphic” and a high resolution icon for use in the store listing.
  • Use the App Inventor provided keystore file, or use a keystore file you have created elsewhere or previously.
  • Build and export your app as a .apk file to your computer.
  • Create a title for your app in the store
  • Write a description for your app to appear in the store
  • Decide on free versus paid (paid requires a “merchant account” to be set up).
  • Upload your apk file, keystore file, image files and title and description, and provide some additional information (such as product category, pricing, and target audience).

Continue reading How to Place Your App Inventor Apps in the Google Play Store

App Inventor course available in Spanish

Estructurado en 8 módulos y con más de 146 clases este curso es ideal para aquellas personas que, sin tener idea de programación, quieren tener un curso completo de App Inventor paso a paso y basado en la metodología de aprender haciendo.

Curso de Desarrollo de aplicaciones móviles Android con App Inventor

The 22 hour online course is offered through the udemy.com

(I did not make clear – sorry – this course is from Professor José Luis Núñez and he is offering it through udemy.com. I am not involved in this at all – just sharing the link – Ed)

How to use the “2 Button” Notifier dialog box

A reader asked, “When using the 2 button Notifier dialog, how do we know which button was pressed?

The 2 button Notifier dialog alert box displays 3 buttons(!) – the first two have values you specify, such as “Ok” and “Done”, as shown here, and the third is an optional generic “Cancel” button:

Screenshot_2015-09-11-15-07-15

The Notifier component block is a procedure call that has no return value – so how can you determine which button was selected?

The answer is that the selected button is returned to a separate event handler.

Continue reading How to use the “2 Button” Notifier dialog box

Tip: Using component colors to find components in the Blocks Editor

Finding a specific programming block with in the AI2 Blocks editor can be hard for new AI programmers.

You found a great code example online and want to recreate it by entering the blocks in to your program – but you cannot find that red block in the middle of the code sample? Where is it? !!!

You start poking around the drop down lists, scanning up and down the pop up menus, missing it the first time(!) and then going through all the blocks again until you finally locate that darned block! Frustrating!

Continue reading Tip: Using component colors to find components in the Blocks Editor

App Inventor 2: Databases and Files – available shortly

Volume 3 – focusing on TinyDB, TinyWebDB, Fusion Tables and text files – is now Available.

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App Inventor 2: Databases and Files is a step-by-step guide to writing apps that use TinyDB, TinyWebDB, Fusion Tables and data files for information storage and retrieval. Includes detailed explanations, examples, and a link to download sample code. This is the first tutorial to cover all of these App Inventor database and file features.

If your apps need to work with data or files – you need this book!

TinyDB stores data on your smart phone or tablet and is a primary way for App Inventor apps to save data, even when the app is no longer running or if the device is turned off.

TinyWebDB is similar to TinyDB, but stores your data on a remote server in the network cloud.

Multiple apps can share a TinyWebDB database, plus you can update the content of your TinyWebDB using just a web browser. This means you can distribute an app whose content can change over time – just by changing the values in TinyWebDB.

A big challenge is the need to set up a TinyWebDB server – this book shows how to do that through free services offered by Google.

Fusion Tables provide a powerful, cloud-based database system for App Inventor apps. Creating, retrieving, updating and deleting data is done using the industry standard Structured Query Language or SQL. Fusion Tables reside in the Google network cloud – this book shows you how to set up and configure Fusion Tables for you own apps using free services of Google. As your app requirements grow, Google’s cloud can provide low cost servers and bandwidth for your needs.

Underneath the Android OS user interface, there is a file system, similar to the file system found on Windows or Mac OS X. With App Inventor your apps can write and read data from files, and if using the special “CSV” format, App Inventor data can be shared with many spreadsheet programs. This book shows you how to create, use and access data files, and how to convert data to and from the CSV format.

Over 28,000 words. Amazon’s page count is 322 pages. Over 250 screen shots and illustrations. Numerous sample programs and code.

App Inventor 2: Databases and Files – Table of Contents
1 – Introduction
2 – Using the TinyDB database
3 – Implementing Records Using Lists in TinyDB
4 – Simulating Multiple TinyDB Databases
5 – How to Use Multiple Tags in TinyDB
6 – Introduction and Setup: TinyWebDB
7 – Managing TinyWebDB in the Cloud
8 – Programming for TinyWebDB – Demo 1
9 – Adding a Tags List to TinyWebDB – Demo 2
10 – Handling Multiple Users with TinyWebDB – Demo 3
11 – Implementing a Student Quiz Application using TinyWebDB
12 – Introduction to Fusion Tables
13 – Developing Your Fusion Table App
14 – Using Text Files in App Inventor

New Linux OS version designed for Android & App Inventor app development

The Appril release of Quirky Linux includes the Android SDK (Software Development Kit), Android Studio, App Inventor, Oracle JDK (Java Development Kit), and LiveCode tools, as well as all of their dependencies, together with the JWM (Joe’s Window Manager) and ROX, providing one of the lightest environments for Android app developers.

“The intention is to have out-of-the-box, just-click-and-get-going Android app development, catering for total non-programmers with App Inventor, through intermediate with LiveCode, to hard-core coders with Android Studio,” says Barry Kauler, Puppy Linux creator.

Source: Puppy Linux’s Sister Quirky 7.1 Distro Arrives with Tools for Android App Developers

It actually runs the App Inventor system on the computer – does not require access to appinventor.mit.edu.

Download here (its free, of course). I have not tried this yet but would be interested to hear reports from users!

 

Example of the new App Inventor “Responsive Design” Feature

MIT App Inventor introduced today their new “responsive design” features so that apps can work “better” on different sized screens. Using these new features, you can create a single app that should run on both a smart phone and a tablet, yet still display proportional user interface controls. Prior to this, your nicely designed smart phone app could end up having very small buttons or text boxes when run on a tablet; now, these components will resize as needed.

The name “responsive” comes from the ability of the app to “respond” to the size of the device and to change the size of controls so they maintain a similar size on each device. The terminology “responsive web design” also refers to web sites that are designed to work with different sized mobile device screens – here is a link to a great article about responsive web site design, passed to us by reader David – thanks!

Continue reading Example of the new App Inventor “Responsive Design” Feature

App Inventor to add “Responsive Design” features next week

MIT App Inventor upgrade coming next Monday – the upgrade will support apps running on devices with different size screens, such as a smart phone versus a tablet.

There’s one important rule when using App Inventor to create apps with responsive design:

Specify widths and heights of components as percentages of the screen width and height, rather than as fixed numbers of pixels.

For example, to make a button whose width is half the screen width, set the button’s width to be 50 percent rather than setting it to a specific number of pixels.

See Responsive Design in App Inventor

Please see the link for details on this upcoming change.

Apps written in Java and the Android SDK have access to additional methods of creating flexible design layouts, or even multiple layouts, for different screen sizes.

MIT begins testing “App Inventor Extension Components”

MIT has begun testing a new App Inventor feature that will enable developers to create their own “extension components”. Extension components are written in Java. Once created and tested, these new components may be shared with other App Inventor developers for use in programs.

What this means: if App Inventor lacks a feature or capability, then a Java developer familiar with App Inventor and its components software development kit will be able to add new features to App Inventor. Over time, the capabilities and power of App Inventor are likely to grow enormously – and rapidly. The ability to extend App Inventor’s features/components is an exciting and tremendously important development for the future of App Inventor!

For now, this feature is in “test mode”.

Source: App Inventor Extension Components available for testing | Explore MIT App Inventor

App Inventor Stores Numbers as “Floating Point” Format

When you type a number, such as “123”, computers convert the text values of “123” into an internal representation used by the computer. There are many possible ways that numbers can be represented inside a computer. For example, the computer could:

  • keep numbers in their original text format “123” (decimal format)
  • convert them into a binary representation (binary integers)
  • a “floating point” representation (floating point or “float” format)
  • or even a “binary coded decimal” (BCD) representation.

Each internal format has benefits and drawbacks, depending on the application. Most computers (and programming systems) convert entered numbers from their original text format into either integer format or floating-point number format.

App Inventor converts values to floating point format. Which is fine, except that you will encounter some odd and subtle issues. As the link below notes, in App Inventor arithmetic, 0.3 + 0.6 does not equal 0.9!

Continue reading App Inventor Stores Numbers as “Floating Point” Format