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- Cool_Drum
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1 post
Creating extensions for Scratch 3.0
when green flag clicked
when green flag clicked
- megastudios_keegan
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28 posts
Creating extensions for Scratch 3.0
how do you get to the place to make themCreating extensions for Scratch 3.0There is now official documentation regarding extensions!, but feel free to use this post to get you started
You'll want to start off by creating your extension's class, and register the extension - In my case, this would be ‘NitroBlock’class NitroBlock { //In both instances, NitroBlock will be the name in both instances } Scratch.extensions.register(new NitroBlock());
Next, we will be constructing block and menu definitions - We will continue to use ‘NitroBlock’ through this tutorialgetInfo() { return { "id": "NitroBlock", "name": "NitroBlock", "blocks": [ ], "menus": { //we will get back to this in a later tutorial } }; }
We are going to take a look at how blocks are constructed
For those of you that are familiar with extensions for Scratch 2.0, we will start off with this: - If not, you can ignore this['r', 'letters %n through %n of %s', 'substringy', '2', '5', 'hello world'] //breakdown below: ['r' = block type, 'letters %n through %n of %s' = block text, 'substringy' = block ID/opcode]{ "opcode": "substringy", //This will be the ID code for the block "blockType": "reporter", //This can either be Boolean, reporter, command, or hat "text": "letters [num1] through [num2] of [string]", //This is the block text, and how it will display in the Scratch interface "arguments": { //Arguments are the input fields in the block. In the block text, place arguments in square brackets with the corresponding ID "num1": { //This is the ID for your argument "type": "number", //This can be either Boolean, number, or string "defaultValue": "2" //This is the default text that will appear in the input field, you can leave this blank if you wish }, "num2": { "type": "number", "defaultValue": "5" }, "string": { "type": "string", "defaultValue": "hello world" } } },
We will put this newly constructed code into the blocks object above - My code will now look like thisclass NitroBlock { getInfo() { return { "id": "NitroBlock", "name": "NitroBlock", "blocks": [{ "opcode": "substringy", "blockType": "reporter", "text": "letters [num1] through [num2] of [string]", "arguments": { "num1": { "type": "number", "defaultValue": "2" }, "num2": { "type": "number", "defaultValue": "5" }, "string": { "type": "string", "defaultValue": "hello world" } } }, }], "menus": { //we will get back to this in a later tutorial } }; } Scratch.extensions.register(new NitroBlock());
Next we come to the most important part, the code that actually runs the blocks! - I am keeping this short and simple for tutorial's sake.//Make sure you name this function with with the proper ID for the block you defined above substringy({num1, num2, string}) { //these names will match the argument names you used earlier, and will be used as the variables in your code //this code can be anything you want return string.substring(num1 - 1, num2); //for reporters and Boolean blocks the important thing is to use 'return' to get the value back into Scratch. }
Place this new code below your getInfo() functionclass NitroBlock { getInfo() { return { "id": "NitroBlock", "name": "NitroBlock", "blocks": [{ "opcode": "substringy", "blockType": "reporter", "text": "letters [num1] through [num2] of [string]", "arguments": { "num1": { "type": "number", "defaultValue": "2" }, "num2": { "type": "number", "defaultValue": "5" }, "string": { "type": "string", "defaultValue": "hello world" } } }, }], "menus": { //we will get back to this in a later tutorial } }; substringy({num1, num2, string}) { return string.substring(num1 - 1, num2); }; }
Save this code to your computer as a js file, in my case it is NitroBlock_3.js
Congratz, you now have your extension code created!!
You can use this tutorial to add it your own personal copy of scratch
Or, you can host the extension with gh-pages, and go here to test it (provide your own url, don't use mine)
Here is the archived copy of my original post
- Boss_1s
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100+ posts
Creating extensions for Scratch 3.0
I tried npm install in the terminal but it gave me the following error:
> scratch-blocks@0.1.0 prepublish
> python build.py && webpack
Traceback (most recent call last):
File “/workspaces/scratch-blocks/scratch-blocks/build.py”, line 39, in <module>
raise Exception(“Blockly build only compatible with Python 2.x.\n”
Exception: Blockly build only compatible with Python 2.x.
You are using: 3.10.8 (main, Oct 5 2023, 20:05:15)
npm ERR! code 1
npm ERR! path /workspaces/scratch-blocks/scratch-blocks
npm ERR! command failed
npm ERR! command sh -c python build.py && webpack
npm ERR! A complete log of this run can be found in: /home/codespace/.npm/_logs/2023-10-20T17_34_08_713Z-debug-0.log
My browser / operating system: ChromeOS 14816.131.0, Chrome 103.0.0.0, No Flash version detected
I have already git cloned the …/google/closure-library repo on Github Codespace.
> scratch-blocks@0.1.0 prepublish
> python build.py && webpack
Traceback (most recent call last):
File “/workspaces/scratch-blocks/scratch-blocks/build.py”, line 39, in <module>
raise Exception(“Blockly build only compatible with Python 2.x.\n”
Exception: Blockly build only compatible with Python 2.x.
You are using: 3.10.8 (main, Oct 5 2023, 20:05:15)
npm ERR! code 1
npm ERR! path /workspaces/scratch-blocks/scratch-blocks
npm ERR! command failed
npm ERR! command sh -c python build.py && webpack
npm ERR! A complete log of this run can be found in: /home/codespace/.npm/_logs/2023-10-20T17_34_08_713Z-debug-0.log
My browser / operating system: ChromeOS 14816.131.0, Chrome 103.0.0.0, No Flash version detected
I have already git cloned the …/google/closure-library repo on Github Codespace.
- SteveMart5
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13 posts
Creating extensions for Scratch 3.0
beter blocks
when [ enter] key pressed
define <drop downs v>[numbers]
if <true v> then
end
- ExpungleCat2023
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13 posts
Creating extensions for Scratch 3.0
i thought this was dead ;-;
start sound [cave_noise v] :: sound hat
if <when flag clicked> then
run hat (move (10) steps :: hat) :: custom
pause [your mom v] for [a dillion] seconds :: control
end
- flappiepapie
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3 posts
Creating extensions for Scratch 3.0
They Should Make a Text Engine Extension
- khilfimango555
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15 posts
Creating extensions for Scratch 3.0
define (define(define))
define
(join [define] [])
- khilfimango555
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15 posts
Creating extensions for Scratch 3.0
play sound [cave_noise_minecraft.mp3]
if <when green flag clicked> then
Run hat <move 10 steps>
- win889888
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21 posts
Creating extensions for Scratch 3.0
<can we have more simple version plz also can it support Mac>
Last edited by win889888 (Dec. 25, 2023 16:46:05)
- Elliot3-0
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100+ posts
Creating extensions for Scratch 3.0
when green flag clicked
draw with pen [...]
we need this block
Last edited by Elliot3-0 (Dec. 25, 2023 16:52:17)
- legoscode
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25 posts
Creating extensions for Scratch 3.0
is there any good places to test out custom extensions other than sheeptesters mod and turbowarp?
- tugael06
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46 posts
Creating extensions for Scratch 3.0
I don't know, But get away from my face 
Let's make a dance block
First use this code:
Now click the Green flag button to start dancing forever!

Let's make a dance block

First use this code:
when green flag clicked
forever
move (34) stepsend
change y by (8)
glide (1) secs to x: (0) y: (0)
Now click the Green flag button to start dancing forever!
- tugael06
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46 posts
Creating extensions for Scratch 3.0
Let's make a block!
Use this block
define
Use this block
define
change y by (input)
glide (1) secs to x: (x position) y: (0)
- tugael06
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46 posts
Creating extensions for Scratch 3.0
Masha:
Good job Pablo! you said 39!
Also me:
Good job Pablo! you said 39!
Also me:
forever
stamp
- ggGamerpoke
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61 posts
Creating extensions for Scratch 3.0
if <when green flag clicked
end> then
- tugael06
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46 posts
Creating extensions for Scratch 3.0
Zoey:
<<(1) < (6)> and <key (space) pressed?>>