在反应组件内使用自定义对象 [英] Use custom object inside react component

问题描述

我想我真的没有得到这个概念。我想在react组件中创建一个自定义对象。自定义对象本身会创建新元素。

I guess I really don't get the concept. I want to create a custom object inside a react component. The custom objects itself creates new elements.

例如：我有一个自定义对象

For example: I have a custom object

function LabelEditor(canvas, width, height) {

    this.canvas = canvas;
    this.canvas.width = width;
    this.canvas.height = height;
    this.canvas.id = 'mainEditor';
    this.canvas.getContext('2d');

    console.log('hi ' + this.canvas.width  + ' / ' + this.canvas.height);

    this.getCanvas = function() {
        return this.canvas;
    };
}

现在我想访问此对象创建的属性，函数和元素反应组件内部，如下所示：

Now I want to access the properties, functions and the elements created by this object inside a react component, something like this:

var Editor = React.createClass({
    render: function() {
        return (
            <div>{this.props.editor.getCanvas()}</div>
        );
    }
});

React.render(
    <Editor editor={new LabelEditor(React.DOM.canvas, 500, 500)} />,
    document.getElementsByTagName('editor')[0]
);

但道具，州和某事的每一个组合现在都失败了。

But every combination of props, state and something have failed by now.

这背后的想法是，我想用fabric.js构建一个编辑器，但想在 React.js中使用它申请。 fabric.js 功能将包含在自定义对象中，并带有控制操作的界面。我想只使用React作为可视部分， LabelEditor -object将作为控制器，而 fabric.js 作为某种模型，提供一个可绘制的画布。

The idea behind this is, I want to build an editor with fabric.js, but want to use it inside a React.js application. The fabric.js functionality will be wrapped inside a custom object with an interface to control the actions. I want to use React only as the visual part, the LabelEditor-object will as a controller, and the the fabric.js as some sort of model, providing a drawable canvas.

推荐答案

下面是我如何构造代码（查看此JSBin 以获得有效的演示）。基本上，编辑器组件呈现< canvas> ，您将在 componentDidMount（）中实例化LabelEditor。你使用 React.findDOMNode（）因为< canvas> 在 render（）表示虚拟DOM，您需要找到相应的DOM。现在， LabelEditor 可以进行绘图。

Below is how I would structure the code (See this JSBin for a working demo). Basically, Editor component renders <canvas> and you would instantiate your LabelEditor in componentDidMount(). You use React.findDOMNode() because <canvas> in render() represents a virtual DOM and you would need to find the corresponding DOM. Now, LabelEditor can do the drawing.

function LabelEditor(canvas, width, height) {
  this.canvas = canvas;
  this.canvas.width = width;
  this.canvas.height = height;
  this.canvas.id = 'mainEditor';

  // Draw something
  var ctx = this.canvas.getContext('2d');
  ctx.fillStyle = "#A0EBDD"
  ctx.fillRect(30, 30, 150, 150);
}

var Editor = React.createClass({
  componentDidMount: function() {
    var canvas = React.findDOMNode(this.refs.canvas);
    this._editor = new LabelEditor(canvas, this.props.width, this.props.height);
  },

  render: function() {
    return (
      <canvas ref="canvas"></canvas>
    );
  }
});

React.render(
  <Editor width={500} height={500} />,
  document.getElementById('editor')
);

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