Week 8 – 2014 Scratch Beginners

Hi everyone,

Good to see so many of you there again on Saturday.

At the start of the session, I talked about what will be happening on April the 12th when we will be awarding belts. If you have any questions or are unsure about anything, please ask me in the next session.


This week we again tried to use all the coding fundementals we have learned so far, such as loops, decisions, animation etc., and put them into a new game. Unlike last week though where the game was an action game this weeks was more of a brain teaser/maths game.


Next week, you are going to work on the game that you will show to us the following week. We will be on hand to help you along if you have any questions.

Looking forward to seeing all your great ideas!

The full notes from this weeks sessions are here in PDF form CDA-S3-MathsGame

Welcome to App Inventor

Today we are going to use App Inventor to create Android apps. App Inventor is created by MIT (Massachusetts Institute of Technology) who are the same people who created Scratch.

App Inventor is browser based and the projects are stored entirely in a cloud at MIT.

Currently the supported browsers are:

  • Mozilla Firefox 3.6 or higher
  • Note: If you are using Firefox with the NoScript extension, you’ll need to turn the extension off. See the note on the troubleshooting page.
  • Apple Safari 5.0 or higher
  • Google Chrome 4.0 or higher
  • Microsoft Internet Explorer is not supported.


App Inventor works on the following Operating Systems

  • Windows XP, Windows Vista, Windows 7
  • Mac OS X 10.5 or higher
  • GNU/Linux: Ubuntu 8 or higher, Debian 5 or higher


The following slides cover the steps to install Firefox and the App Inventor software.

Week 1 – How to install App Inventor

The following slides cover the steps to update the App Inventor software.

Week 1 – How to update App Inventor


Once the software has been installed we will create our 1st app using App Inventor.

Week 1 – Speaking App

ModderDojo Java Modding 12: Creating our First Block


Getting Started

IMPORTANT: For this block mod code to work, you need at least release 1024 of Forge 1.7.2. It will not work with releases 999 that we downloaded before. (Explanation: Forge works by decompiling the Minecraft code, which gives fields and methods automatic names like func_149739_a(). The Forge people have to translate these into meaningful names, like getUnlocalizedName(). They had not done this for the Material fields in earlier releases.)

You can download the source here: http://files.minecraftforge.net/maven/net/minecraftforge/forge/1.7.2-

You will need to unzip it and run the two gradlew commands – see Post 2.

Thanks to Eli and Ailish who between them were the first to get this working.

Files Needed

Very similarly to creating an Item mod (see Post 8) you need at least 4 things to create a new Block mod:

  1. A new block class that extends the standard Block class
  2. A mod class where you add it to the game registry (you can just add some lines to one you have already)
  3. A language file where you specify its name
  4. A texture file to control its appearance

I am keeping this code in the same package I already used for our item mod, modderdojo.firstitem.


The Block Class

Create a Java file in this package called MyFirstBlock with this code:

// Michael Madden March 2014.
// Ref: http://www.minecraftforge.net/wiki/Basic_Items
// Thanks to Ailish and Eli in CoderDojo Athenry who figured this out originally. 

package modderdojo.firstitem;

import net.minecraft.block.Block;
import net.minecraft.block.material.Material;
import net.minecraft.creativetab.CreativeTabs;

public class MyFirstBlock extends Block
 public MyFirstBlock()
 // This is the constructor for our new item. Set basic properties in it.
 super(Material.iron); // Copy the properties of iron

 setBlockName("MichaelFirstBlock"); // This is the internal name, not display name



Adding It to the Registry

Add this code to the preInit method in your main mod class (in my case called MyFirstMod):

 // Register my block and set its texture
 MyFirstBlock b = new MyFirstBlock();
 b.setBlockTextureName("modderdojo:mmblock"); // requires .png file with this name
 GameRegistry.registerBlock(b, "MichaelFirstBlock");


For this step, you need to create a texture that will be used on all sides of the block.

Using a graphics package such as Paint.NET, create an image of size 32 x 32 (other sizes that are powers of 2 are also OK). Save it in PNG format.

In the src/main/resources folder, create a new package called assets.modderdojo.textures.blocks (just like the one you did for your first item, but with blocks instead of items in its name). Put the PNG file in it. In my case, the file is called mmblock.png.

In your main mod class preInit method, add/update this line:


The name you set is based on where you put it “assets.modderdojo.textures.blocks” followed by a colon “:” followed by the name of the PNG file put without “.png”: mmblock.png.


If you run your code now (and it’s a good idea to keep running after every step, to test what you have done), you will see that your block has the name tile.MichaelFirstBlock.name. To give it a better name, add a line to the language file, en_US.lang:

tile.MichaelFirstBlock.name=Michael's First Block Display Name


ModderDojo Java Modding 11: Packaging our First Mod


This post is based on these instructions:
The main steps are:

  1. Edit build.gradle and change the group and archiveBaseName entries
  2. Run gradlew build
  3. In the folder build – lib, you will find your Jar file: you can post this on a website for other people to use.

To install Forge if you don’t already have it installed:

  1. Download it here: http://www.minecraftforge.net/forum/index.php?action=files
  2. Look for 1.7.2-Recommended and then click on Installer-Win
  3. Select “Client install”
    1. You will end up with a new Minecraft profile called Forge
    2. Select this to run Minecraft with Forge

To install your new mod (or any Forge mod):

  1. Open Windows Explorer and enter %appdata% as the location
  2. Open the .minecraft folder and then the lib folder
  3. Copy your new mod Jar file into lib

Next time you run Minecraft with the Forge profile, you will see your mod.


Previous post: ModderDojo Java Modding 10: A Recipe for Our New Item.

Week 7 2014 – Scratch Beginners

Hi Everyone,

Thank you all for coming again this week and thank you to Oliver for taking the session for the two weeks I was away.

I briefly spoke about Belts last week and we will go into that further in this coming session.


I tried to do a game this week that was jammed packed with everything you have learned so far, Loops, decisions, variables, broadcasting and animation.


It was quite a lot to fit in but I think we managed it. If any of you are having problems with your code, we can take a look at it before our next session, or have a look through this weeks notes and see can you figure it out yourself.

Here are this weeks notes in PDF: CDA-S3-Wipeout

Web Development – Week 5

Hi all, This weeks notes show you how to place a link to a YouTube video inside your webpage! Visitors to your website can see the video playing directly on your web page, the notes also have a look at what ‘HTTP’ is, it stands for Hypertext Transfer Protocol. Don’t let the name put you off though, it’s really just like a language that computer use to talk over the internet. Remember if you have any questions my email address is on the last slide of the notes and I am at Coderdojo Athenry on Saturdays! WebsiteDevelopment5