Cloud Storage: TinyWebDB

MIT App Inventor includes a TinyDB component which allows a simple database to be created on the Android device; this could be used to store a local high score in a game, for example. TinyDB is also useful for passing data between screens in a multi-screen app, as normally it's only possible to pass one value between screens.

There's also a cloud-based equivalent, TinyWebDB, which allows data to be stored online: it can therefore be shared between different apps and different devices. This could be used to store a global high score, shared with all players of a game, and updated if they beat it. It could also be used to build a rudimentary message storage and retrieval system, allowing messages to be sent from one client device to another via a central server: the basis of email or messaging.

The default cloud-based database is a shared resource, and data written to it will be overwritten at some point, depending on how many other App Inventor apps are using it.

We have therefore created a new TinyWebDB service specifically for UniTY teachers and students: it is still shared of course, but only among participating schools. Data should therefore be persistent provided (a) unique keys are used to prevent accidentally deleting or modifying someone else's data, and (b) nobody deliberately deletes or modifies data other than their own. Be warned that data stored in the database is not private!

The UniTY database can be selected by setting the ServiceURL to http://unity-dcu-tinywebdb.appspot.com/

A demo app using TinyDB and TinyWebDB has been added to the UniTY section of the app library.

Resizing images for the Brainstormer Quiz app

For those students who want to use their own images in the Who-Is-Quiz app built as part of the Core 2: Brainstormer project, it's best to resize the images before uploading them to App Inventor. Most image processing programs offer the ability to resize or scale an image: one such program is Autodesk Pixlr, which can either be downloaded and installed as a desktop app, or used online as a web app called Pixlr Express - the latter is useful if students do not have install rights on their PCs. For the quiz, a maximum image dimension (height or width) of 240 pixels should work well for most images.

Also, a reminder that the Project Notes for Core 2: Brainstormer (http://unitydcu.ie/ss-c2n) include important information about fixing a crash in the version of the app described in the videos.

Inspirational Video Example

Hi All,

The Journal.ie covered this video this morning by one of our final year students studying Journalism in DCU, Laura Horan.

The video is very simple and straightforward but the message is powerful. I would encourage you to show it to your students to inspire them for their own video ideas.

It is an excellent example to show how an honest story of someone speaking from the heart can be very moving and powerful.

Enjoy.
Darran

Near Field Communications (NFC) Demo

App Inventor supports very basic Near Field Communications (NFC) capability, allowing the reading and writing of text tags. NFC is the short range communications protocol that underlies contactless payments ('tap to pay') capabilities on credit and debit cards, as well as services like Samsung Pay that allow a phone to be used for payments. It's also used in Leap Cards, office access badges, and hotel room keycards.

An app to read and wite NFC tags has been added to the UniTY section of the App Library. Some things to consider before trying out the app:

1. NFC is not supported on Amazon Fire tablets, but is supported on many Android phones.
2. NFC tags must already be configured as Text Tags to work with this app; this can be done with an app such as NFC Tools, as most NFC tags are blank when purchased.
3. NFC tags can be purchased directly from companies such as ZipNFC or through their eBay store for under 50c each, plus postage.

App Orientation (BlueStacks)

The BlueStacks emulator opens in landscape mode every time, and can only be switched to portrait after an app is running. The sample Smart Skills apps provided at the Download link for each project have therefore been updated to set the Screen1 property ScreenOrientation to Portrait. This automatically switches BlueStacks to portrait mode when the app is launched.

This change also forces the Nox emulator to switch to portrait mode when the app is launched, however with Nox it is possible to configure the initial screen size and orientation in the Advanced Settings, which should be set to Phone and 480x800 for optimum compatibility with the apps.

This change has no effect on ARC Welder orientation, which must be set when an app is first loaded in each session, as described in the previous post.

ARC Welder: Invisible Dropdowns

Those of you using ARC Welder to test apps may have noticed a problem with "invisible dropdowns" when trying to set the recommended Orientation (Portrait) and Form Factor (Phone) on first use. As shown below, the triangle points upward when the selector is clicked, but the dropdown is not visible.

This appears to be intermittent and is a recent problem, possibly introduced with the current version of ARC Welder in early August. The dropdowns are in fact still active, but are invisible: it is therefore still possible to select the desired Orientation and Form Factor by clicking once to open the dropdown (triangle points upwards), and then clicking where the desired option should appear, by reference to the images below. Typically the desired settings are Portrait for Orientation, and Phone for Form Factor.

 

While not ideal, and potentially difficult to have students do successfully, this at least allows the orientation and form factor of ARC Welder to be set to match the apps created by App Inventor. On the positive side, it only needs to be done once per session, provided ARC Welder is not closed.

The images with the dropdowns visible as expected were taken from the version of Chrome Portable and ARC Welder provided on a USB during the Smart Skills Training sessions. This may be a viable alternative, at the cost of needing to manually copy Chrome Portable onto every student PC, and ensuring that students open Chrome Portable and not the normal Chrome installation when using App Inventor and ARC Welder.

DCU / CompuB Apple Professional Development

Below is a link to the Apple Professional Development training which will take place in DCU on Monday 10th October 2016.

The workshop will take place from 9.30 to 12.30 (3 hours in duration) and is aimed at beginners and intermediate users of iPads in the Classroom.

Priority will be given to teachers delivering the UniTY modules, however it is available to any teachers in your school who may benefit from this type of training. Max 2 teachers from each school.

The training is free of charge and places will be allocated on a first come first served basis. Should places fill in the morning session, I will investigate a second session if the demand is there.

http://doodle.com/poll/6kgmv2ck4k4yaf7r

Please fill in your name AND school (in the same box) when signing up on the Poll below.