Polymer.dart 中国际化字符串中的 HTML 标记答案

【问题标题】：HTML Tags Within Internationalized Strings In Polymer.dartPolymer.dart 中国际化字符串中的 HTML 标记
【发布时间】：2014-01-19 00:51:57
【问题描述】：

我在 Polymer 元素中显示国际化字符串，如下所示：

<div>
  <span class="title">{{title}}</span>
  <br/><br/>
  <span class="subtitle">{{subtitle1}}</span>
  <br/>
  <span class="content">{{paragraph1}}</span>
  <br/><br/>
  <span class="subtitle">{{subtitle2}}</span>
  <br/>
  <span class="content">{{paragraph2}}</span>
</div>

...并具有以下飞镖代码：

@observable String title;
@observable String subtitle1;
@observable String paragraph1;
@observable String subtitle2;
@observable String paragraph2;

//...

void onUpdateLocale(_locale) {
  title = getTitle();
  subtitle1 = getSubtitle1();
  paragraph1 = getParagraph1();
  subtitle2 = getSubtitle2();
  paragraph2 = getParagraph2();
}

//...

getTitle() => Intl.message('MY TITLE', name:'title',
    desc: 'This is my title',
    args: [],
    examples: {'None' : 0});
getSubtitle1() => Intl.message('Subtitle 1', name:'subtitle1',
    desc: 'This is my first subtitle',
    args: [],
    examples: {'None' : 0});
getParagraph1() => Intl.message('This is my first paragraph',
    name:'paragraph1',
    desc: 'This is the my first paragraph',
    args: [],
    examples: {'None' : 0});
getSubtitle2() => Intl.message('Subtitle 2', name:'subtitle1',
    desc: 'This is my second subtitle',
    args: [],
    examples: {'None' : 0});
getParagraph2() => Intl.message('This is my second paragraph',
    name:'paragraph2',
    desc: 'This is the my second paragraph',
    args: [],
    examples: {'None' : 0});

有没有办法将title、subtitle1、paragraph1、subtitle2 和 paragraph2 组合成一个可观察变量，其中包含   和  标记的值？

【问题讨论】：

Bind content containing html tags 的可能重复项
谢谢，君特。你知道 safe-html 聚合物元素会是什么样子吗？

标签： internationalization dart dart-polymer dart-html

【解决方案1】：

更新

Dart Polymer 1.0 的即用型元素是bwu-bind-html

更新

Polymer 现在提供开箱即用的支持

 this.injectBoundHTML('<div>your HTML goes here ${someBoundFieldValue}</div>);

旧

这是我正在使用的<safe-html> 标签的代码。

library safe_html;

import 'dart:async';
import "dart:html";

import "package:polymer/polymer.dart";


@CustomTag("safe-html")
class SafeHtml extends PolymerElement  {

  @published String model;

  NodeValidator nodeValidator;
  bool get applyAuthorStyles => true;
  bool isInitialized = false;

  SafeHtml.created() : super.created() {
    nodeValidator = new NodeValidatorBuilder()
    ..allowTextElements();
  }

  void modelChanded(old) {
    if(isInitialized) {
      _addFragment();
    }
  }

  void _addFragment() {
    var fragment = new DocumentFragment.html(model, validator: nodeValidator);
    $["container"].nodes
    ..clear()
    ..add(fragment);

  }

  @override
  void attached() {
    super.attached();
    Timer.run(() {
      _addFragment();
      isInitialized = true;
    });
  }
}

<!DOCTYPE html>

<polymer-element name="safe-html"> 
  <template>
    <div id="container"></div>
  </template>

  <script type="application/dart" src='safe_html.dart'></script>

</polymer-element>

用法：

<safe-html model="{{someField}}></safe-html>

【讨论】：

谢谢，君特。当我将您的元素用作<safe-html model="{{myContent}}"><safe-html> 时，我收到以下错误并且内容没有采用样式。 Removing disallowed attribute Removing disallowed attribute Removing disallowed attribute Removing disallowed attribute Removing disallowed attribute 
您可以自定义NodeValidator。我添加了行 `..allowElement('SPAN', attributes: ['class']);` 作为示例（实际上没有尝试过 - 希望它仍然有效）
allowHtml5() 显然不包括“脚本元素、样式属性和任何脚本处理程序”（from API dartdoc）。
此元素的功劳归于stackoverflow.com/questions/19316300（刚刚再次偶然发现）