2.0 Modding for Newbs

1. If you don't already have it, install git.
   
2. Run the command
   

   git clone https://github.com/LLK/scratch-flash

1. Open a terminal.
   
2. Change the directory to the one containing the Scratch source code (the one containing the src directory, not the src directory itself) by running
   

   cd <path to source code>

3. If you're using a Unix-like OS, run
   

   ./gradlew build

   If you're using Windows, run
   

   gradlew.bat build

4. If all goes well, Scratch can be found at build/11.6/Scratch.swf. If you get an error, and you've made changes to the code, then it's likely a problem with your code.
   
   If you get an error saying

   Redirection detected from https to http. Protocol switch unsafe, not allowed.

   then manually download OSMF_1.0.zip and put it in <your home directory>/.gradle/gradleFx/sdks/<some number>/in. (Thanks Jonathan50)
   

Blocks are defined in the Specs.as file in the “src” file, in an array called commands. Each block definition is also an array, in the format of

["block name", "block type", block category, "block primitive name", default arguments...]

Block Name

The block's name contains the text, inputs, and icons on the block. Inputs (called arguments) are defined in the format of %<letter>.<optional menu type>. For example, %n creates a number input, and %m.direction creates a direction menu.

Icons are defined in the format of @<icon name>. For example, @greenFlag will create a green flag icon, and @stop will create a stop sign icon. You can find a complete list of argument types, menus, and icons here.

Block Type

The block type defines what shape a block will be. Valid values are:

• “ ” - a stack block
  
• “w” - a wait block defined in extensions
  
• “b” - a boolean
  
• “r” - a reporter
  
• “R” - requester, a reporter that requests data and waits until it's been received
  
• “h” - a hat block
  
• “c” - a C block
  
• “cf” - a final C block, like “forever”
  
• “e” - an “if then, else” shaped block
  
• “f” - a cap block, like "stop [all v]"
  
• “o” - the stack block outline for “define” blocks
  
• “p” - the “define” block shape
  

Block Category

This defines what category a block will appear in. Valid values are:

• 0 - undefined
  
• 1 - Motion
  
• 2 - Looks
  
• 3 - Sound
  
• 4 - Pen
  
• 5 - Events
  
• 6 - Control
  
• 7 - Sensing
  
• 8 - Operators
  
• 9 - Data
  
• 10 - More Blocks
  
• 11 - Parameter (inside custom block definitions)
  
• 12 - List
  
• 20 - Extension
  

For categories with blocks specific to the sprite and stage (like Looks), the number above defines a block for sprites only, and the number+100 defines the block for the stage only.

Block Primitive Name

This is the name of the “primitive” that defines what a block does. I'll show you how to define this later. If the block's primitive isn't defined, then the block will appear gray and do nothing.

Default Arguments

The default values for arguments are defined here. For example,

["say %s for %n secs", " ", 2, "say:duration:elapsed:from:", "Hello!", 2]

makes the "say [ ] for ( ) secs" block have the default arguments “Hello” and 2.

Block primitives are defined in one of the files in the “primitives” folder, depending on the block's category. List primitives go in ListPrims.as, Looks primitives go in LooksPrims.as, Motion and Pen primitives go in MotionAndPenPrims.as, Sensing primitives go in SensingPrims.as, Sound primitives go in SoundPrims.as, Video Motion Primitives go in VideoMotionPrims.as, and all other primitives go in Primitives.as.

To define primitives, you need to add a line to the addPrimsTo function in one of the Primitives classes, in the format of

primTable['<primitive name>'] = <function name>;

private function <function name>(b:Block):void {
	<code for block>
}

In the Looks specs in the Specs.as, add the line

		["Hello, world!",						" ", 2, "helloWorld"],

In the addPrimsTo function in LooksPrims.as, add the line

		primTable['helloWorld']						= helloWorld;

In the LooksPrims.as file, add the function

	private function helloWorld(b:Block):void {
		var s:ScratchSprite = interp.targetSprite();
		if (s == null) return;
		s.showBubble("Hello, world!", "talk", b);
		if (s.visible) interp.redraw();
	}

If all goes well, it should make a sprite say “Hello, world!”.

• Adding Categories by @nXIII
  

davidkt wrote:

Do you know how to add blocks? I'm sifting through the four files of block code, trying to figure out where to start. Scratch 1.4 modding was definitely easier.

If you're using Windows, make sure to use forward slashes ('/') as the directory separator instead of the normal backslashes ('\'). For example, C:\fake\path\to\flex becomes Cfake/path/to/flex.

If you're using Windows, make sure to use back slashes ('\') as the directory separator instead of the normal forward slashes ('/'). For example, Cfake/path/to/flex becomes C:\fake\path\to\flex.

arungupta wrote:

Is modding the same as creating a new plugin for Scratch ?

Is there any tutorial that shows how to create a simple plugin ?

Mrcomputer1 wrote:

what are the Reserved posts for?

williambl wrote:

I think I saw a mistake:

If you're using Windows, make sure to use forward slashes ('/') as the directory separator instead of the normal backslashes ('\'). For example, C:\fake\path\to\flex becomes Cfake/path/to/flex.

should be

If you're using Windows, make sure to use back slashes ('\') as the directory separator instead of the normal forward slashes ('/'). For example, Cfake/path/to/flex becomes C:\fake\path\to\flex.

Linux and OS/X use ‘/’, while windows uses ‘\’. You've stated the opposite.

DigiTechs wrote:

The title should totally be ‘Scratch 2.0 Modding for Dummies’ instead.

Because, you know. I'm a dummy when it comes to these things.

arungupta wrote:

Is modding the same as creating a new plugin for Scratch ?

Is there any tutorial that shows how to create a simple plugin ?

DigiTechs wrote:

http://helpx.adobe.com/flash-builder/release-note/flex-4-6-sdk-release.html has some useful tips for installing on Linux, and to install ant it's more than likely:

sudo apt-get install ant

djdolphin wrote:

davidkt wrote:

Do you know how to add blocks? I'm sifting through the four files of block code, trying to figure out where to start. Scratch 1.4 modding was definitely easier.

Edit Specs.as to add block specs, and the blocks' code goes into one of the .as files in the primitives folder.

davidkt wrote:

Glad this is stickied. Any idea how to compile?

GP1 wrote:

I suggest that in your adding blocks section you add that if a block doesn't have corresponding code, the block will appear “gray”. That confused me a bit, since in Scratch 1.X adding a blockspec will color the block as well. (As a comment, that is a kinda smart move on the Scratch team's part, since now we know which blocks have code if we forget to program them in).

djdolphin wrote:

davidkt wrote:

Glad this is stickied. Any idea how to compile?

Eh, no one seems to read stickies. As for how to compile, look in the first post. I added instructions yesterday.

davidkt wrote:

Thanks!!!!!!!