如blockly文档的Code Generators章节里所说，用户在blockly编辑器中写好了程序之后(积木组合)，程序往往需要被转化为某一门编程语言（JavaScript, Python, PHP, Lua, Dart等），以便于执行它
比如我们在blockly开发之hello world(0)中写的这个程序
我们想运行它，以便检验你的数学能力
运行代码
分几个步骤
generate (从积木中生成代码)
原始版本
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<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Blockly Demo: Fixed Blockly</title>
<script src="../../blockly_compressed.js"></script>
<script src="../../blocks_compressed.js"></script>
<script src="../../msg/js/en.js"></script>
<style>
body {
background-color: #fff;
font-family: sans-serif;
}
h1 {
font-weight: normal;
font-size: 140%;
}
</style>
</head>
<body>
<h1><a href="https://developers.google.com/blockly/">Blockly</a> >
<a href="../index.html">Demos</a> > Fixed Blockly</h1>
<p>This is a simple demo of injecting Blockly into a fixed-sized 'div' element.</p>
<p>→ More info on <a href="https://developers.google.com/blockly/guides/configure-blockly/web/fixed-size">injecting fixed-sized Blockly</a>…</p>
<div id="blocklyDiv" style="height: 480px; width: 600px;"></div>
<xml id="toolbox" style="display: none">
<block type="controls_if"></block>
<block type="logic_compare"></block>
<block type="controls_repeat_ext"></block>
<block type="math_number"></block>
<block type="math_arithmetic"></block>
<block type="text"></block>
<block type="text_print"></block>
</xml>
<script>
var demoWorkspace = Blockly.inject('blocklyDiv',
{ media: '../../media/',
toolbox: document.getElementById('toolbox')}
);
</script>
</body>
</html>
|
增加的部分
参考: blockly/demos/generator/index.html
引入依赖
<script src="../../javascript_compressed.js"></script>
这个js文件的功能是用于生成<script src="../../blocks_compressed.js"></script>预定义的积木对应的js代码
此外通过引入其他语言模块，我们还可以将blocks_compressed.js预知的积木块生成python、Python, PHP, Lua, Dart等待
javascript_compressed.js需要在blockly_compressed.js之后被引用
生成代码
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function showCode() {
// Generate JavaScript code and display it.
Blockly.JavaScript.INFINITE_LOOP_TRAP = null;
var code = Blockly.JavaScript.workspaceToCode(demoWorkspace);
console.log(code);
}
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运行代码
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function runCode() {
// Generate JavaScript code and run it.
window.LoopTrap = 1000;
Blockly.JavaScript.INFINITE_LOOP_TRAP =
'if (--window.LoopTrap == 0) throw "Infinite loop.";\n';
var code = Blockly.JavaScript.workspaceToCode(demoWorkspace);
Blockly.JavaScript.INFINITE_LOOP_TRAP = null;
try {
eval(code);
} catch (e) {
alert(e);
}
}
|
添加按钮
添加两个按钮把事件关联起来
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<p>
<button onclick="showCode()">Show JavaScript</button>
<button onclick="runCode()">Run JavaScript</button>
</p>
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完整版本
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<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Blockly Demo: Fixed Blockly</title>
<script src="../../blockly_compressed.js"></script>
<script src="../../blocks_compressed.js"></script>
<script src="../../javascript_compressed.js"></script>
<script src="../../msg/js/en.js"></script>
<style>
body {
background-color: #fff;
font-family: sans-serif;
}
h1 {
font-weight: normal;
font-size: 140%;
}
</style>
</head>
<body>
<h1><a href="https://developers.google.com/blockly/">Blockly</a> >
<a href="../index.html">Demos</a> > Fixed Blockly</h1>
<p>This is a simple demo of injecting Blockly into a fixed-sized 'div' element.</p>
<p>→ More info on <a href="https://developers.google.com/blockly/guides/configure-blockly/web/fixed-size">injecting fixed-sized Blockly</a>…</p>
<p>
<button onclick="showCode()">Show JavaScript</button>
<button onclick="runCode()">Run JavaScript</button>
</p>
<div id="blocklyDiv" style="height: 480px; width: 600px;"></div>
<xml id="toolbox" style="display: none">
<block type="controls_if"></block>
<block type="logic_compare"></block>
<block type="controls_repeat_ext"></block>
<block type="math_number"></block>
<block type="math_arithmetic"></block>
<block type="text"></block>
<block type="text_print"></block>
</xml>
<script>
var demoWorkspace = Blockly.inject('blocklyDiv',
{ media: '../../media/',
toolbox: document.getElementById('toolbox')}
);
function showCode() {
// Generate JavaScript code and display it.
Blockly.JavaScript.INFINITE_LOOP_TRAP = null;
var code = Blockly.JavaScript.workspaceToCode(demoWorkspace);
console.log(code);
}
function runCode() {
// Generate JavaScript code and run it.
window.LoopTrap = 1000;
Blockly.JavaScript.INFINITE_LOOP_TRAP =
'if (--window.LoopTrap == 0) throw "Infinite loop.";\n';
var code = Blockly.JavaScript.workspaceToCode(demoWorkspace);
Blockly.JavaScript.INFINITE_LOOP_TRAP = null;
try {
eval(code);
} catch (e) {
alert(e);
}
}
</script>
</body>
</html>
|
run
以js运行
如果你回答对了:
如果你答错了:
延伸
我最近在写一份blockly的入门和进阶教程，这个官方教程也被我纳入其中，在教程的第二节blockly_2_generate_and_run_js，目前教程以源码的形式出现:wwj718/blockly_dev，还没写成博客。大家能阅读js的话，可以自行阅读。或者等我有空补上文章。
参考
