代码生成器

Blockly 的大多数应用都要求将用户程序翻译为编程语言。此操作由 Blockly 在客户端执行。

生成代码

第一步是添加相关语言的生成器。Blockly 包含以下生成器：

  • JavaScript
  • Python
  • PHP
  • Lua
  • Dart

您可以通过以下方法之一导入和使用生成器。

模块

import {javascriptGenerator} from 'blockly/javascript';
import {pythonGenerator} from 'blockly/python';
import {phpGenerator} from 'blockly/php';
import {luaGenerator} from 'blockly/lua';
import {dartGenerator} from 'blockly/dart';

const jsCode = javascriptGenerator.workspaceToCode(workspace);
const pythonCode = pythonGenerator.workspaceToCode(workspace);
const phpCode = phpGenerator.workspaceToCode(workspace);
const luaCode = luaGenerator.workspaceToCode(workspace);
const dartCode = dartGenerator.workspaceToCode(workspace);

卸载

您必须先添加 Blockly，然后才能添加生成器。

<script src="https://unpkg.com/blockly"></script>
<script src="https://unpkg.com/blockly/javascript_compressed"></script>
<script src="https://unpkg.com/blockly/python_compressed"></script>
<script src="https://unpkg.com/blockly/php_compressed"></script>
<script src="https://unpkg.com/blockly/lua_compressed"></script>
<script src="https://unpkg.com/blockly/dart_compressed"></script>

const jsCode = javascript.workspaceToCode(workspace);
const pythonCode = python.workspaceToCode(workspace);
const phpCode = php.workspaceToCode(workspace);
const luaCode = luna.workspaceToCode(workspace);
const dartCode = dart.workspaceToCode(workspace);

本地脚本

您必须先添加 Blockly，然后才能添加生成器。

<script src="blockly_compressed.js"></script>
<script src="javascript_compressed.js"></script>
<script src="python_compressed.js"></script>
<script src="php_compressed.js"></script>
<script src="lua_compressed.js"></script>
<script src="dart_compressed.js"></script>

const jsCode = javascript.workspaceToCode(workspace);
const pythonCode = python.workspaceToCode(workspace);
const phpCode = php.workspaceToCode(workspace);
const luaCode = lua.workspaceToCode(workspace);
const dartCode = dart.workspaceToCode(workspace);

实时生成

生成代码是一项非常快的操作，因此频繁调用此函数没有坏处。一种常见的策略是通过向 Blockly 的更改事件添加监听器来实时生成并显示代码：

import {javascriptGenerator} from 'blockly/javascript';
function updateCode(event) {
  const code = javascriptGenerator.workspaceToCode(workspace);
  document.getElementById('textarea').value = code;
}
workspace.addChangeListener(updateCode);

如需了解详情，请参阅事件。