Polymer

Question

我正在尝试像示例一样在我的应用程序中复制多个 iron-collapses，但运行出现问题： https://elements.polymer-project.org/elements/iron-collapse?view=demo:demo/index.html&active=iron-collapse

我得到的错误是：

[my-app::_createEventHandler]: listener method `_expandClicked('#collapse1')` not defined

标记

<a>
    <span>Parent Link 1</span>
    <paper-icon-button icon="expand-more" role="button" on-click="_expandClicked('#collapse1')"></paper-icon-button>
</a>
<iron-collapse id="collapse1">
    <a class="link" href="/view2">Sport F</a>
    <a class="link" href="/view3">Child C</a>
</iron-collapse>

函数

_expandClicked: function(selector) {
    document.querySelector(selector).toggle();
    // Don't propagate to the anchor link.
    event.preventDefault();
    event.stopImmediatePropagation();
}

有什么想法吗？谢谢！

Answer 1

设置事件侦听器可以读取的 annotated event listener, the value must be the method name only. You could pass a function argument as a data attribute 时。

// template
<paper-button on-tap="_toggleCollapse" data-selector="#collapse1">

// script
_toggleCollapse: function(e) {
  const selector = e.target.dataset.selector;
  this.$$(selector).toggle();
}

HTMLImports.whenReady(() => {
  "use strict";

  Polymer({
    is: 'x-foo',
    _toggleCollapse: function(e) {
      // Assume e.target is the paper-button or an immediate child
      const selector = e.target.dataset.selector || e.target.parentElement.dataset.selector;
      if (selector) {
        this.$$(selector).toggle();
      }
    }
  });
});

<head>
  <base href="https://polygit.org/polymer+1.6.1/components/">
  <script src="webcomponentsjs/webcomponents-lite.min.js"></script>
  
  <link rel="import" href="paper-button/paper-button.html">
  <link rel="import" href="iron-collapse/iron-collapse.html">
  <link rel="import" href="iron-icons/iron-icons.html">
</head>
<body>
  <x-foo></x-foo>

  <dom-module id="x-foo">
    <template>
      <style>
        :host {
          font-family: Roboto, Noto, sans-serif;
        }

        section {
          margin-top: 20px;
        }

        paper-button {
          background: #eee;
          width: 100%;
          text-transform: none;
          justify-content: flex-start;
          font-size: 18px;
        }
        
        .content {
          margin-left: 6px;
          padding: 15px;
          border: 1px solid #dedede;
          width: calc(100% - 34px);
          border: 1px solid #dedede;
          border-top: none;
          border-bottom-left-radius: 5px;
          border-bottom-right-radius: 5px;
          box-shadow: 0 2px 2px 0 rgba(0, 0, 0, 0.14), 0 1px 5px 0 rgba(0, 0, 0, 0.12), 0 3px 1px -2px rgba(0, 0, 0, 0.2);
        }
      </style>
      <section>
        <paper-button on-tap="_toggleCollapse" data-selector="#collapse1">
          <span>Collapse #1</span>
          <iron-icon icon="expand-more"></iron-icon>
        </paper-button>
        <iron-collapse id="collapse1">
          <div class="content">
            Lorem ipsum dolor sit amet, per in nusquam nominavi periculis, sit elit oportere ea, id minim maiestatis incorrupte duo. Dolorum verterem ad ius, his et nullam verterem. Eu alia debet usu, an doming tritani est. Vix ad ponderum petentium suavitate, eum eu tempor populo, graece sententiae constituam vim ex. Cu torquatos reprimique neglegentur nec, voluptua periculis has ut, at eos discere deleniti sensibus. Lorem ipsum dolor sit amet, per in nusquam nominavi periculis, sit elit oportere ea, id minim maiestatis incorrupte duo. Dolorum verterem ad ius, his et nullam verterem. Eu alia debet usu, an doming tritani est. Vix ad ponderum petentium suavitate, eum eu tempor populo, graece sententiae constituam vim ex. Cu torquatos reprimique neglegentur nec, voluptua periculis has ut, at eos discere deleniti sensibus.
          </div>
        </iron-collapse>
      </section>
      <section>
        <paper-button on-tap="_toggleCollapse" data-selector="#collapse2">
          <span>Collapse #2</span>
          <iron-icon icon="expand-more"></iron-icon>
        </paper-button>
        <iron-collapse id="collapse2">
          <div class="content">
            Pro saepe pertinax ei, ad pri animal labores suscipiantur. Modus commodo minimum eum te, vero utinam assueverit per eu, zril oportere suscipiantur pri te. Partem percipitur deterruisset ad sea, at eam suas luptatum dissentiunt. No error alienum pro, erant senserit ex mei, pri semper alterum no. Ut habemus menandri vulputate mea. Feugiat verterem ut sed. Dolores maiestatis id per. Pro saepe pertinax ei, ad pri animal labores suscipiantur. Modus commodo minimum eum te, vero utinam assueverit per eu, zril oportere suscipiantur pri te. Partem percipitur deterruisset ad sea, at eam suas luptatum dissentiunt. No error alienum pro, erant senserit ex mei, pri semper alterum no. Ut habemus menandri vulputate mea. Feugiat verterem ut sed. Dolores maiestatis id per.
          </div>
        </iron-collapse>
      </section>
    </template>
  </dom-module>
</body>

codepen

Polymer - 使用计算绑定的多个手风琴

Polymer - Multiple accordions using computed bindings

javascript

polymer-1.0