All About Buttons

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Buttons are an essential component in creating mobile apps on App Inventor. You can use them to do things like submit information, navigate screens, clear data, and stop or start game play. Here is a quick intro guide to creating and using buttons in App Inventor.

The Button component is found at the top of the User Interface Palette in the Designer.

Click on the Button at the top of the User Interface Palette (#1) on the left side of the screen and drag it to the Viewer (#2). The Button automatically displays “Text for Button1”, which you can easily change in the properties panel text box (near the bottom on the far right of the screen, #3).

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Changing the text that appears on the button is part of the UI design that the app user will see. Depending on what the button will be used for, it could display instructions like: “Submit,” “Next,” “Play,” etc.

Note: Changing the button display text should not be confused with renaming the button. Changing the button name helps you, the designer/coder, to keep your buttons organized. Thus “SubmitButton” is an appropriate name for a button that displays the text “Submit”.

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A key coding principle for buttons (and for many components) is naming them appropriately. Whenever you create a new button in the Designer, it will automatically be named Button1, Button2, Button3, etc. When you first start building apps, your interface will be simple and thus it will be easy to keep track of which buttons perform which functions. But as you progress to creating more complex applications, you will quickly discover that it is difficult to remember what Button7 or Button14 does. Thus, it is good practice to rename buttons to clearly describe their function so that when you begin coding in the Blocks Editor, each button purpose is obvious.

The recommended standard is to use a capitalized descriptive name, followed by the capitalized component name – with no spaces between words. Examples include: “SubmitButton”, “NextButton” or “PlayButton”. (AppInventor doesn’t allow spaces so if you type the name “Submit Button” with a space in between the words, App Inventor will automatically insert an underscore and name your button “Submit_Button”.)Screen Shot 2016-06-21 at 9.58.14 PM

To rename a button, activate it by clicking on it in the Viewer or in the Components Panel (it will highlight with a light green box around the name). Then click the “Rename” button at the bottom of the Components Panel (#4). A pop-up window will appear, insert the new name into the text box and click “OK” (#5).

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Note: If for example you rename your first button from Button1 to “PlayButton”, and then drag another button onto the Viewer, App Inventor will name it Button1 even though it is not the first button you created. ThScreen Shot 2016-06-21 at 10.10.21 PM.pngis example illustrates the importance of not relying on the order of creation, but rather on appropriate naming to keep buttons organized.

Any changes you make in the Designer will be reflected in the Blocks Editor (#6). Notice at the bottom of the Blocks Palette, there is another option to Rename (or delete) buttons. Thus, changes can be made there as well.

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If you decide that a button is no longer needed, deleting it is simple. Click on the button in the Viewer or Components Panel in the Designer or in the Blocks Panel in the Editor and then click “Delete”. A pop-up window will confirm deletion (#7). Click “OK”.

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The Properties Panel in the Designer provides many options to change the format of your buttons. Click on the button in the Viewer or the Components Panel to see a list of options. The changes you make to the properties are reflected in the Viewer (#8 & #9).

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And of course, to get the full effect of how your app will look, it is always recommended to view your changes live on your mobile device or with the on-screen emulator.

For information on coding buttons, stay tuned for All About Buttons, Part 2.

 

FirebaseDB

FirebaseDB is the new App Inventor web database. Kind of. The uncertainty stems from the fact that this new web database component is currently being beta tested and will be updated based on user feedback. You can try it out, but don’t get too attached to its current form, because features may change by the time it is fully integrated. In case you forget this fact, you will be reminded every time you try to add this component to your project. Housed under the “Experimental” Palette drawer in the Designer, dragging this non-visible component to the Viewer will result in an alert reminding you of its provisional existence.

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I already love FirebaseDB and use it as if its current form were a permanent addition to my coding repertoire. Why is FirebaseDB so great?

Databases are used for many of reasons in mobile apps such as: to keep track of high scores in a game, to count the number of votes in an election, to save a variety outgoing text messages or to store the names of RSVPs to a book club event. FirebaseDB stores data in the cloud, which is helpful if you are perhaps vying to become a high scorer of a game. For such apps, both the app programmer and app user want this sort of data to be shared and persistent, meaning that once the app closes, the information is not gone forever, it will be saved and retrieved for all to see once the app reopens.

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Example: For a simple note-taking app, users enter their username and a note and the app will display the note, the username and a time/date stamp. For this app to work, it must save and display notes from different users on various devices- a perfect scenario for FirebaseDB.

We programed this app so that when the user clicks “Submit,” the app stores data using the StoreValue block. In this case, it adds the values (user’s name, note, and date/time stamp) to a list called “global notes”. This information gets stored in the FirebaseDB under the tag that we named, “notelist”.

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Each time the app opens, the GetValue block requests the most updated values stored under the “notelist” tag from the Firebase Service. When the value is received, the GotValue event fires retrieving the values saved in “notelist” and displays them in a List View.

The Firebase DataChanged event gets triggered anytime any user adds a new note. This is the amazing part because with FirebaseDB, all app instances receive this data and thus, are consistent. The previous App Inventor web database, TinyWebDB, did not have the ability to share data globally in this manner.

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To become familiar with FirebaseDB, try building this note taker app and test how values from various users get saved, updated and displayed Or better yet, build a game app and see people around the world vie for the top scorer position!

 

 

 

*Note that the App Inventor emulator does not support the FirebaseDB component.

 

 

App Inventor Education Taking off in China!

There are many stories about competition and strife in US-China relations, as well as the profound differences in our cultures. This is a story, instead, of collaboration, the story of US and Chinese citizens uniting for the common goal of better educating students for the 21st century. What better agent than education to illustrate the amazing commonalities between peoples?

MIT App Inventor is the catalyst of change, a coding language perfectly suited for teaching and inspiring young people to learn how to create and solve problems in our rapidly digitizing world. While App Inventor education has rapidly expanded in the US since its inception at Google in 2009, it has been widely unavailable in China. Thanks to the efforts of the extended MIT App Inventor team and some extraordinary educators in China, this creative way of teaching computational thinking is now also taking off in China.

Hal Abelson, director of the MIT App Inventor team, has led the project from the US side. App Inventor was inaccessible in China because it runs on Google infrastructure, so Hal, Jeff Schiller, Weihua Li, Andrew McKinney, and others facilitated the creation of a version that runs on a different infrastructure and thus can be accessed in China.

But this was only the start. With the help of the extraordinary MIT student Weihua Li, a plan was set in place to jumpstart App Inventor education in China through teacher and student workshops starting in the summer of 2014. The idea spread like rapid-fire and led to the 1st International Conference on Mobile Learning and Computational Thinking Education, Based on App Inventor, which was held in Guangzhou in June (2015)..

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Attendees of the App Inventor Conference in Guangzhou. See if you can pick me (David Wolber) out. Hint: I’m the tallest.

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Li Yue, South China Univ. of Technology

 

The conference included representatives from Hong Kong, Taiwan, UK, UNESCO, and the US, as well as over 200 educators from all over China.

I was honored to speak at the conference and to teach a workshop to some K-12 and university teachers. Ralph Morelli of Trinity College and mobile-csp.org also spoke and gave a workshop to about sixty middle schoolers, shown below. MIT was represented by Tech Lead Andrew McKinney, Felicia Kamriani, and the aforementioned WeiHua Li, who spoke at the conference and was also the key translator for the English speakers.

The real story, however, is the amazing efforts of educators in China who are helping spread App Inventor based education throughout the region and country. It is a joint university and governmental project perhaps best exemplified by South China University Professor Li Yue, the conference organizer who has led numerous teacher training workshops throughout South China. I was honored to see her in action, using her relentless energy and charm to teach and inspire.

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The students at Ralph Morelli’s workshop were extremely diligent as Ralph walked them through building a “Selfie-Slideshow app”

Dr. Li organized a visit to a school where we saw first hand how App Inventor is making a difference: a roomful of energetic middle school students energized about building apps. Ralph Morelli gave them a workshop, teaching them how to build a “Selfie-Slideshow” app, and it was incredible to see the joy on the student’s faces. On a personal basis, I was happy to see that the students were using a translated version of the App Inventor book I co-authored (along with Hal, Ellen Spertus, and Liz Looney).

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http://www.17coding.net has a translated version of the book App Inventor: Create your own Android Apps

The conference and workshops didn’t solve the world’s problems, but a group of educators from East and West shared ideas on how best to educate young people for the jobs of tomorrow (as well as ideas on one-child policies, free speech, gun control, and the best Beatles songs to play at Karaouke). It was a highlight of my career to participate, not only to help spread a great method of educating students, but to help promote a collaborative spirit between the peoples of China and the US.

App Inventor now has a Gallery!

App Inventor programmers have been working side-by-side in the cloud together, but they might as well have been using stand-alone software as they couldn’t share their experience. I’m pleased to announce that the App Inventor app gallery is officially launched as part of MIT App Inventor. Students and developers can now easily share their apps and code blocks and learn from each other. The gallery turns App Inventor into a shared learning community similar to the one which has been so successful in Scratch. Now all the students, teachers, and developers who were blindly rubbing virtual shoulders can share their apps in a great, collaborative open-source environment.
Click on any app to open it and see its blocks

Click on any app to open it and see its blocks

The gallery was developed by our team in the Democratize Computing Lab (DCL) at the University of San Francisco (the same team that brings you appinventor.org and this blog), working in collaboration with the MIT App Inventor team. Special thanks go to lead developers Bin Lu and Vincent Zhang of USF, as well as mastermind Jeff Schiller of MIT, all of whom put in a long and concerted effort in making the gallery a reality.

The Democratize Computing Lab is generously funded by the W.M. Keck Foundation.

App Inventor Teacher Workshop this Summer in SF!

The University of San Francisco and AppInventor.org will host an App Inventor teacher twitter-usftag-500x500workshop and follow-up activities during the summer of 2015. The workshop will take place over four days, June 29-July 2, 2015, 10 am to 3 pm each day, at the University of San Francisco. The workshop is funded by USF and the Google CS4HS program. You can apply at b​it.ly/usfWorkshop.

What
Learn App Inventor coding and how to teach it in a 4­-day teacher development workshop funded by Google and USF. Coding apps for phones and tablets is a fantastic way to learn computer science and computational thinking! The workshop is free. If you can commit to teaching in 2015-­2016, you may also be eligible for a $1000 stipend!

Who
Teachers from all levels are welcome to participate. No prior coding experience is required. The workshop will start at the beginning with both coding and the App Inventor language, and will focus on how to teach the material to beginners. The workshop will be taught by USF Professor Alark Joshi and USF Professor and App Inventor author David Wolber.

Where
University of San Francisco Campus, 2130 Fulton Street, San Francisco, CA 94117

Details
appinventororgThe workshop will prepare you for teaching either a complete programming course or a coding module in an existing course. The topics and material discussed will be appropriate for many programming courses and levels, including the High School Computer Science Principles (CSP) curriculum that is being piloted as a new AP course. You will be introduced to two popular existing on­line courses, Mobile CSP (m​obile­-csp.org)​ and Professor Wolber’s App Inventor Course­-in­-a­-Box (a​ppinventor.org)​.

Community of Practice
Our goal is to foster the community of App Inventor teachers in the Bay Area. We will offer two ways to continue after the workshop: (1) We’ll provide three weeks of follow­-up guidance after the workshop (July 6­-24, 2015) including once­-a­-week  meetups as you continue with the Mobile CSP on-­line course, and (2) During the school year, we have funds for a limited number of USF students, experienced in App Inventor programming, to assist you in the classroom. If you can commit to teaching App Inventor in 2015­-16, you may be eligible for a $1000 stipend.

Application
Please apply for the workshop at b​it.ly/usfWorkshop. ​Slots for the workshop are limited, but we will accommodate as many teachers as we can.

Democratizing Computing with App Inventor: new article

Screen Shot 2015-02-11 at 10.36.53 AMI teamed up with App Inventor creators Hal Abelson (MIT) and Mark Friedman (Google) on the article, “Democratizing Computing with App Inventor”, which was recently published as first education column in the inaugural issue of Get Mobile ( from ACM SIGMOBILE Mobile Computing and Communications Review). Hal and Mark developed App Inventor from the ground up at Google. Hal continues to lead its development at MIT with Mark contributing significantly. The article introduces App Inventor and its history, and tells some of the great success stories.

The article is now available here and in the ACM Digital library.

Street Code Academy Rocks

It is the damndest hackathon coding workshop you’ve ever seen. There is music. Loud Music. Hip Hop.  Dance a little, sing a little, create an app! There are basketball hoops, low for dunking (even low enough for an old has-been). Hoop it up, app it up! There are colorful murals. There is barbecue. Eat a bit, code a bit. And the barbecue is out of control good!

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Kids coding, and Rafael Cosman teaching, at the Street Code academy Kickoff event

There are black people. And brown people. People of all colors. Silicon Valley meet East Palo Alto. This is the Street Code Academy Kickoff event.

There are kids. All ages. There are Moms and dads. Families. Having fun and learning to code and create. Design the Future, say the T-shirts. They will and they are.

The kids are smiling, learning, having fun, proud. Empowered is a big word but you see it in the kids faces. Look what I can do!

Some kids spent 11 hours on the day hacking. A girl named Harshita Gupta from Mission San Jose High met with the Mayor and prototyped an app for East Palo Alto residents to report trash/graffiti (she’s spending her thanksgiving week off working no it!) Kids worked with Arduino boards, App Inventor, Wix, Photoshop, and just about every technology you can think of.

Google and Facebook, your numbers on diversity are awful. Street Code Academy is the change you envision. Check it out!

The academy is run by young visionaries: Rafael Cosman, Olatunde Sobomehin, Shadi Barhoumi. They are techies but they are experts in what kids like. They are coaches and cheerleaders and mentors. There is no kid that could resist Olatunde’s call to arms! Rafael’s energy is infectious. Shadi is everywhere. These guys are on to something big.

Support the Street Code Academy!

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The music was off the charts

BarbecueStreetCode

Best barbecue ever and 100 times better than any previous hackathon event



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Olatunde Sobomehin inspired young and old

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