如何在Polymer.dart元素中嵌入D3图表? [英] How to embed a D3 chart in a Polymer.dart element?

问题描述

浏览器:Dartium版本34.0.1847.0(258268)

Browser: Dartium Version 34.0.1847.0 (258268)

我想将D3嵌入Polymer.dart元素中，我才刚刚开始理清Dart和JS的交互方式.我首先从D3入门指南如何制作酒吧的HTML5/CSS3/JS创建普通HTML页面开始图表，以确保我的D3实施在Dartium中可用.

I want to embed D3 inside Polymer.dart elements and I'm just beginning to sort out how Dart and JS interoperate. I started by creating a vanilla HTML page using HTML5/CSS3/JS from D3's introductory tutorial on how to make a bar chart to be sure my D3 implementation worked in Dartium.

然后，我将D3代码移动到自定义聚合物元素(如下所示)及其配套的dart源文件(未显示)中.如何指示D3在阴影DOM中执行选择?

I then moved the D3 code into a custom polymer element (shown below) and its companion dart source file (not shown). How do I instruct D3 to perform its selection inside the shadow DOM?

<!-- D3 code copied from: http://bost.ocks.org/mike/bar/ -->
<polymer-element name="dart-js">
    <template>
        <!-- D3 style -->
        <style>
            .chart div {
                font: 10px sans-serif;
                background-color: steelblue;
                text-align: right;
                padding: 3px;
                margin: 1px;
                color: white;
            }
        </style>

        <content>
            <!-- D3 container -->
            <div class="chart">inside dart-js shadow-root</div>

            <!-- D3 JS -->
            <script type="application/javascript">
                console.log("inside content");

                var data = [4, 8, 15, 16, 23, 42];
                console.log("data: " + data); // data: 4,8,15,16,23,42

                console.log("select: <" + d3.select(".chart") + ">"); // select: <>

                // How do I instruct d3 to search inside the shadow DOM?
                d3.select(".chart")
                        .selectAll("div")
                        .data(data)
                        .enter().append("div")
                        .style("width", function (d) { return d * 10 + "px"; })
                        .text(function (d) { return d; })

            </script>
        </content>

    </template>
    <script type="application/dart;component=1" src="dart_js.dart"></script>
</polymer-element>

推荐答案

d3不能在shadowDOM中找到元素，但是您可以在Dart中查找该元素并将其传递给d3的select方法.

d3 can't find elements inside a shadowDOM but you look up the element in Dart and pass it to d3's select method.

类似的东西(未经测试)

something like this (not tested)

import 'dart:js' as js;

js.context['d3'].callMethod('select', [shadowRoot.querySelector('.chart')]);

有关Dart-JS-interop的更多信息: https://www.dartlang.org/articles/js-dart-interop/

more info about Dart-JS-interop: https://www.dartlang.org/articles/js-dart-interop/

这篇关于如何在Polymer.dart元素中嵌入D3图表?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！