Polymer 2 新页面获取 404

Question

我已经按照聚合物指南创建了一个新页面：https://www.polymer-project.org/2.0/start/toolbox/create-a-page。但是当我点击导航菜单项 "New view" 时，我得到 "Oops you hit a 404. Head back to home." 而不是我的新视图。我尝试编辑现有页面，一切似乎都正常，但我的新页面却不行。我的文件和教程一模一样，我查了很多。

我的-app.html:

<!--
@license
Copyright (c) 2016 The Polymer Project Authors. All rights reserved.
This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
Code distributed by Google as part of the polymer project is also
subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
-->

<link rel="import" href="../bower_components/polymer/polymer-element.html">
<link rel="import" href="../bower_components/app-layout/app-drawer/app-drawer.html">
<link rel="import" href="../bower_components/app-layout/app-drawer-layout/app-drawer-layout.html">
<link rel="import" href="../bower_components/app-layout/app-header/app-header.html">
<link rel="import" href="../bower_components/app-layout/app-header-layout/app-header-layout.html">
<link rel="import" href="../bower_components/app-layout/app-scroll-effects/app-scroll-effects.html">
<link rel="import" href="../bower_components/app-layout/app-toolbar/app-toolbar.html">
<link rel="import" href="../bower_components/app-route/app-location.html">
<link rel="import" href="../bower_components/app-route/app-route.html">
<link rel="import" href="../bower_components/iron-pages/iron-pages.html">
<link rel="import" href="../bower_components/iron-selector/iron-selector.html">
<link rel="import" href="../bower_components/paper-icon-button/paper-icon-button.html">
<link rel="import" href="my-icons.html">

<link rel="lazy-import" href="my-view1.html">
<link rel="lazy-import" href="my-view2.html">
<link rel="lazy-import" href="my-view3.html">
<link rel="lazy-import" href="my-new-view.html">
<link rel="lazy-import" href="my-view404.html">

<dom-module id="my-app">
  <template>
    <style>
      :host {
        --app-primary-color: #4285f4;
        --app-secondary-color: black;

        display: block;
      }

      app-drawer-layout:not([narrow]) [drawer-toggle] {
        display: none;
      }

      app-header {
        color: #fff;
        background-color: var(--app-primary-color);
      }

      app-header paper-icon-button {
        --paper-icon-button-ink-color: white;
      }

      .drawer-list {
        margin: 0 20px;
      }

      .drawer-list a {
        display: block;
        padding: 0 16px;
        text-decoration: none;
        color: var(--app-secondary-color);
        line-height: 40px;
      }

      .drawer-list a.iron-selected {
        color: black;
        font-weight: bold;
      }
    </style>

    <app-location
        route="{{route}}"
        url-space-regex="^[[rootPath]]">
    </app-location>

    <app-route
        route="{{route}}"
        pattern="[[rootPath]]:page"
        data="{{routeData}}"
        tail="{{subroute}}">
    </app-route>

    <app-drawer-layout fullbleed narrow="{{narrow}}">
      <!-- Drawer content -->
      <app-drawer id="drawer" slot="drawer" swipe-open="[[narrow]]">
        <app-toolbar>Menu</app-toolbar>
        <iron-selector selected="[[page]]" attr-for-selected="name" class="drawer-list" role="navigation">
          <a name="view1" href="/view1">View One</a>
          <a name="view2" href="/view2">View Two</a>
          <a name="view3" href="/view3">View Three</a>
          <a name="new-view" href="/new-view">New View</a>
        </iron-selector>
      </app-drawer>

      <!-- Main content -->
      <app-header-layout has-scrolling-region>

        <app-header slot="header" condenses reveals effects="waterfall">
          <app-toolbar>
            <paper-icon-button icon="my-icons:menu" drawer-toggle></paper-icon-button>
            <div main-title>My App</div>
          </app-toolbar>
        </app-header>

        <iron-pages
            selected="[[page]]"
            attr-for-selected="name"
            fallback-selection="view404"
            role="main">
          <my-view1 name="view1"></my-view1>
          <my-view2 name="view2"></my-view2>
          <my-view3 name="view3"></my-view3>
          <my-new-view name="new-view"></my-new-view>
          <my-view404 name="view404"></my-view404>
        </iron-pages>
      </app-header-layout>
    </app-drawer-layout>
  </template>

  <script>
    class MyApp extends Polymer.Element {
      static get is() { return 'my-app'; }

      static get properties() {
        return {
          page: {
            type: String,
            reflectToAttribute: true,
            observer: '_pageChanged',
          },
          routeData: Object,
          subroute: String,
          // This shouldn't be neccessary, but the Analyzer isn't picking up
          // Polymer.Element#rootPath
          rootPath: String,
        };
      }

      static get observers() {
        return [
          '_routePageChanged(routeData.page)',
        ];
      }

      _routePageChanged(page) {
        // If no page was found in the route data, page will be an empty string.
        // Default to 'view1' in that case.
        this.page = page || 'view1';

        // Close a non-persistent drawer when the page & route are changed.
        if (!this.$.drawer.persistent) {
          this.$.drawer.close();
        }
      }

      _pageChanged(page) {
        // Load page import on demand. Show 404 page if fails
        var resolvedPageUrl = this.resolveUrl('my-' + page + '.html');
        Polymer.importHref(
            resolvedPageUrl,
            null,
            this._showPage404.bind(this),
            true);
      }

      _showPage404() {
        this.page = 'view404';
      }
    }

    window.customElements.define(MyApp.is, MyApp);
  </script>
</dom-module>

我的新-view.html:

<!-- Load the Polymer.Element base class -->
<link rel="import" href="../bower_components/polymer/polymer-element.html">

<dom-module id="my-new-view">
  <!-- Defines the element's style and local DOM -->
  <template>
    <style>
      :host {
        display: block;

        padding: 16px;
      }
    </style>

    <h1>New viewwww</h1>
  </template>
  <script>
    // Your new element extends the Polymer.Element base class
    class MyNewView extends Polymer.Element {
      static get is() { return 'my-new-view'; }
    }
    //Now, register your new custom element so the browser can use it
    customElements.define(MyNewView.is, MyNewView);
  </script>
</dom-module>

Answer 1

所有接缝都很好，就像您指向 polymer-project 的页面一样，但您唯一需要更正的地方。如果您想使用 lazy-import 导入您的页面，您需要在 <dome-module> 和 <template> 之间移动此行，例如：

... 
<!--import all necessary library ABOVE as you did and PLUS below  -->
<link rel="import" href="../lazy-imports-mixin.html">
...
<dom-module id="my-app">
    <link rel="lazy-import" group="lazy" href="my-view1.html">
    <link rel="lazy-import" group="lazy" href="my-view2.html">
    <link rel="lazy-import" group="lazy" href="my-view3.html">
    <link rel="lazy-import" group="lazy" href="my-new-view.html">
    <link rel="lazy-import" group="lazy" href="my-view404.html">
  <template>
...

并扩展 Polymer.LazyImportsMixin 的这个元素：

class MyApp extends Polymer.LazyImportsMixin(Polymer.Element) {...

请参考 here

中的 lazy-load 语法

或者您可以简单地在同一个地方导入页面，但没有 lazy-import，例如：

<link rel="import" href="my-view1.html">
<link rel="import" href="my-view2.html">
<link rel="import" href="my-view3.html">
<link rel="import" href="my-new-view.html">
<link rel="import" href="my-view404.html">

Answer 2

实际上是函数 _pageChanged 执行导入，惰性导入只是为了欺骗 linter。

话虽这么说，但除非服务器有问题，否则我不明白为什么它不起作用。

如果您浏览到您的 my-new-view.html 页面，会出现 404 吗？如果是这样，则该页面未被提供。还要查看您的控制台，看看它是否抛出错误。

Answer 3

我猜错误出在函数 __Pagechanged 和链接函数中。请参阅：这取决于您的页面名称 my- 'page '... 我想您应该将页面设为 'my-number_of_page_-view ' 或重写起始代码

Polymer 2 新页面获取 404

Polymer 2 new page getting 404

html

polymer

polymer-2.x