scratch 入门 - Githubissues

壹通用的计算概念

序列(sequence) 确定任务的一系列步骤
循环(loops) 运行相同的序列多次
并行性(parallelism) 相同时间内做不同的事情
事件(events) 一个事情的发生触发另外一个事情
条件(conditionals) 根据条件做出决定
operators 数学或者逻辑的表达
数据(data) 存储查找更新删除数据

贰扩展开发

一些参数


const ArgumentType = require('../../extension-support/argument-type');
const BlockType = require('../../extension-support/block-type');
const Cast = require('../../util/cast');
const log = require('../../util/log');
const nets = require('nets');
const languageNames = require('scratch-translate-extension-languages');
const formatMessage = require('format-message');

/**

Icon svg 会被显示在积木分类菜单, 下面采用data URI的形式.
@type {string} */ const menuIconURI = 'data:image/png;base64,省略==';

/**

Icon svg 会被显示在左边扩展积木栏, 采用data URI的形式.
@type {string} */ const blockIconURI = 'data:image/png;base64,省略==';

/**

The url of the translate server.
@type {string} */ const serverURL = 'https://translate-service.scratch.mit.edu/';

/**

How long to wait in ms before timing out requests to translate server.
@type {int} */ const serverTimeoutMs = 10000; // 10 seconds (chosen arbitrarily).

/**

类 for the translate block in Scratch 3.0.
@constructor */ class Scratch3TranslateBlocks { constructor () { /**
- Language code of the viewer, based on their locale.
- @type {string}
- @private */ this._viewerLanguageCode = this.getViewerLanguageCode();
  
  /**
- List of supported language name and language code pairs, for use in the block menu.
- Filled in by getInfo so it is updated when the interface language changes.
- @type {Array.<object.<string, string>>}
- @private */ this._supportedLanguages = [];
  
  /**
- A randomly selected language code, for use as the default value in the language menu.
- Properly filled in getInfo so it is updated when the interface languages changes.
- @type {string}
- @private */ this._randomLanguageCode = 'en';
  
  /**
- The result from the most recent translation.
- @type {string}
- @private */ this._translateResult = '';
  
  /**
- The language of the text most recently translated.
- @type {string}
- @private */ this._lastLangTranslated = '';
  
  /**
- The text most recently translated.
- @type {string}
- @private */ this._lastTextTranslated = ''; }
/**
- The key to load & store a target's translate state.
- @return {string} The key. */ static get STATE_KEY () { return 'Scratch.translate'; }
/**
- @returns {object} 扩展的元数据和扩展的积木. / getInfo () { this._supportedLanguages = this._getSupportedLanguages(this.getViewerLanguageCode()); this._randomLanguageCode = this._supportedLanguages[ Math.floor(Math.random() this._supportedLanguages.length)].value;
  
  return { id: 'translate', name: formatMessage({ id: 'translate.categoryName', default: 'Translate', description: 'Name of extension that adds translate blocks' }), blockIconURI: blockIconURI, menuIconURI: menuIconURI, blocks: [ { opcode: 'getTranslate', text: formatMessage({ id: 'translate.translateBlock', default: 'translate [WORDS] to [LANGUAGE]', description: 'translate some text to a different language' }), blockType: BlockType.REPORTER, arguments: { WORDS: { type: ArgumentType.STRING, defaultValue: formatMessage({ id: 'translate.defaultTextToTranslate', default: 'hello', description: 'hello: the default text to translate' }) }, LANGUAGE: { type: ArgumentType.STRING, menu: 'languages', defaultValue: this._randomLanguageCode } } }, { opcode: 'getViewerLanguage', text: formatMessage({ id: 'translate.viewerLanguage', default: 'language', description: 'the languge of the project viewer' }), blockType: BlockType.REPORTER, arguments: {} } ], menus: { languages: this._supportedLanguages } }; }
/**
- Computes a list of language code and name pairs for the given language.
- @param {string} code The language code to get the list of language pairs
- @return {Array.<object.<string, string>>} An array of languge name and
- language code pairs.
- @private */ _getSupportedLanguages (code) { return languageNames.menuMap[code].map(entry => { const obj = {text: entry.name, value: entry.code}; return obj; }); } /**
- Get the human readable language value for the reporter block.
- @return {string} the language name of the project viewer. */ getViewerLanguage () { this._viewerLanguageCode = this.getViewerLanguageCode(); const names = languageNames.menuMap[this._viewerLanguageCode]; const langNameObj = names.find(obj => obj.code === this._viewerLanguageCode); let langName = this._viewerLanguageCode; if (langNameObj) { langName = langNameObj.name; } return langName; }
/**
- Get the viewer's language code.
- @return {string} the language code. */ getViewerLanguageCode () { const locale = formatMessage.setup().locale; const viewerLanguages = [locale].concat(navigator.languages); const languageKeys = Object.keys(languageNames.menuMap); // Return the first entry in viewerLanguages that matches // one of the available language keys. const languageCode = viewerLanguages.reduce((acc, lang) => { if (acc) { return acc; } if (languageKeys.indexOf(lang) > -1) { return lang; } return acc; }, '') || 'en'; return languageCode; }
/**
- Get a language code from a block argument. The arg can be a language code
- or a language name, written in any language.
- @param {object} arg A block argument.
- @return {string} A language code. */ getLanguageCodeFromArg (arg) { const languageArg = Cast.toString(arg).toLowerCase(); // Check if the arg matches a language code in the menu. if (languageNames.menuMap.hasOwnProperty(languageArg)) { return languageArg; } // Check for a dropped-in language name, and convert to a language code. if (languageNames.nameMap.hasOwnProperty(languageArg)) { return languageNames.nameMap[languageArg]; } // Default to English. return 'en'; }
/**
- Translates the text in the translate block to the language specified in the menu.
- @param {object} args - the block arguments.
- @return {Promise} - a promise that resolves after the response from the translate server. */ getTranslate (args) { // Don't remake the request if we already have the value. if (this._lastTextTranslated === args.WORDS && this._lastLangTranslated === args.LANGUAGE) { return this._translateResult; }
  
  const lang = this.getLanguageCodeFromArg(args.LANGUAGE);
  
  let urlBase = ${serverURL}translate?language=; urlBase += lang; urlBase += '&text='; urlBase += encodeURIComponent(args.WORDS);
  
  const tempThis = this; const translatePromise = new Promise(resolve => { nets({ url: urlBase, timeout: serverTimeoutMs }, (err, res, body) => { if (err) { log.warn(error fetching translate result! ${res}); resolve(''); return ''; } const translated = JSON.parse(body).result; tempThis._translateResult = translated; // Cache what we just translated so we don't keep making the // same call over and over. tempThis._lastTextTranslated = args.WORDS; tempThis._lastLangTranslated = args.LANGUAGE; resolve(translated); return translated; });
  
  }); translatePromise.then(translatedText => translatedText); return translatePromise; } } module.exports = Scratch3TranslateBlocks;
```
- **开发你的第一个scratch 3.0 extension**
参考 [開發你的第一個 SCRATCH 3.0 EXTENSION](https://blog.everlearn.tw/scratch3/開發你的第一個-scratch-3-0-extension)
- **参考一些在线生成的**
https://github.com/KittenBot/scratch3-extension/blob/master/README_CN.md
```

mkdir Scratch
cd Scratch
git clone https://github.com/llk/scratch-gui
cd scratch-gui
npm install
npm start

http://localhost:8601/ 要应该可以看到scratch 3.0启动了。

利用 SCRATCH-VM 開發 SCRATCH 3.0 EXTENSION

再探 SCRATCH-VM 架構下的 SCRATCH 3.0 EXTENSION

Scratch 资源 Ereignisse 事件 Wenn flag angeklickt 当开始的旗被点击了 Wenn Taste [] gedrückt 当某个按键给按下了 Wenn diese Figur angeklickt Wenn das Bühnenbild zu [] wechselt Wenn Lautstärke > 10 Wenn ich Nachricht1 emfange sende Nachricht1 an alle sende Nachricht1 an alle und warte

Steuerung 控制

microbit扩展的写法 https://github.com/LLK/scratch-vm/blob/develop/src/extensions/scratch3_microbit/index.js