已解决：该问题与我的package.json有关。我检查了它，它在某种程度上是一个较旧的，没有我在帖子中链接的所有脚本和依赖项。但是，我仍然可以运行脚本并最初启动它，一切正常。不知怎的，它是从两个不同的package.json文件中读取的，我假设当热重新加载发生时，它是从旧的那个读取的？...我删除了更新旧文件，运行npm install并且一切正常好了。
在初始页面加载时，站点运行正常并加载正确的数据，但是当我尝试更改某些内容，并检查热重载是否正常时，会抛出这些错误。
Error: The selector "app" did not match any elements
at DomRenderer.selectRootElement (eval at <anonymous> (http://localhost:8080/js/vendor.js:1129:1), <anonymous>:196:23) [angular]
at DebugDomRenderer.selectRootElement (eval at <anonymous> (http://localhost:8080/js/vendor.js:2480:1), <anonymous>:47:56) [angular]
at selectOrCreateRenderHostElement (eval at <anonymous> (http://localhost:8080/js/vendor.js:748:1), <anonymous>:509:32) [angular]
at CompiledTemplate.proxyViewClass.View_AppComponent_Host0.createInternal (/AppModule/AppComponent/host.ngfactory.js:13:16) [angular]
at CompiledTemplate.proxyViewClass.AppView.createHostView (eval at <anonymous> (http://localhost:8080/js/vendor.js:2529:1), <anonymous>:121:21) [angular]
由于它是在初始加载时加载的，我只会发布我的package.json和webpack.config.js。
这是我的package.json。我在一个控制台中运行npm run watch，在另一个控制台中运行npm run start:hmr。
{
"name": "site-pinger",
"version": "1.0.0",
"description": "",
"author": "",
"license": "ISC",
"scripts": {
"clean": "rimraf node_modules doc dist && npm cache clean",
"clean-install": "npm run clean && npm install",
"clean-start": "npm run clean-install && npm start",
"watch": "webpack --watch --progress --profile",
"build": "rimraf dist && webpack --progress --profile --bail",
"server": "webpack-dev-server --inline --progress --port 8080",
"webdriver-update": "webdriver-manager update",
"webdriver-start": "webdriver-manager start",
"lint": "tslint --force \"src/**/*.ts\"",
"e2e": "protractor",
"e2e-live": "protractor --elementExplorer",
"pretest": "npm run lint",
"test": "karma start",
"posttest": "remap-istanbul -i coverage/json/coverage-final.json -o coverage/html -t html",
"test-watch": "karma start --no-single-run --auto-watch",
"ci": "npm run e2e && npm run test",
"docs": "typedoc --options typedoc.json src/app/app.component.ts",
"start": "npm run server",
"start:hmr": "npm run server -- --hot",
"postinstall": "npm run webdriver-update"
},
"devDependencies": {
"@angularclass/hmr": "^1.0.1",
"@angularclass/hmr-loader": "^3.0.2",
"@types/jasmine": "2.5.41",
"@types/node": "^6.0.38",
"@types/selenium-webdriver": "2.53.39",
"@types/lodash": "4.14.50",
"angular2-template-loader": "^0.6.0",
"autoprefixer": "^6.3.2",
"awesome-typescript-loader": "^3.0.0-beta.17",
"codelyzer": "2.0.0",
"copy-webpack-plugin": "^4.0.0",
"css-loader": "^0.26.1",
"extract-text-webpack-plugin": "^2.0.0-beta.4",
"file-loader": "^0.10.0",
"html-loader": "^0.4.0",
"html-webpack-plugin": "^2.8.1",
"istanbul-instrumenter-loader": "^0.2.0",
"jasmine-core": "^2.3.4",
"jasmine-spec-reporter": "^3.2.0",
"json-loader": "^0.5.3",
"karma": "1.4.1",
"karma-chrome-launcher": "^2.0.0",
"karma-coverage": "^1.0.0",
"karma-jasmine": "^1.0.2",
"karma-mocha-reporter": "^2.0.3",
"karma-remap-istanbul": "0.2.1",
"karma-sourcemap-loader": "^0.3.7",
"karma-webpack": "2.0.2",
"node-sass": "^4.5.0",
"null-loader": "0.1.1",
"postcss-loader": "^1.1.0",
"protractor": "^4.0.10",
"raw-loader": "0.5.1",
"remap-istanbul": "^0.6.4",
"rimraf": "^2.5.1",
"sass-loader": "^6.0.1",
"shelljs": "^0.7.0",
"style-loader": "^0.13.0",
"ts-helpers": "^1.1.1",
"tslint": "^4.3.1",
"tslint-loader": "^3.3.0",
"typedoc": "^0.5.1",
"typescript": "2.0.10",
"url-loader": "^0.5.6",
"webpack": "2.2.1",
"webpack-dev-server": "2.3.0"
},
"dependencies": {
"@angular/common": "~2.4.0",
"@angular/compiler": "~2.4.0",
"@angular/core": "~2.4.0",
"@angular/forms": "~2.4.0",
"@angular/http": "~2.4.0",
"@angular/platform-browser": "~2.4.0",
"@angular/platform-browser-dynamic": "~2.4.0",
"@angular/router": "~3.4.0",
"angular-in-memory-web-api": "~0.2.4",
"systemjs": "0.19.40",
"core-js": "^2.4.1",
"reflect-metadata": "^0.1.3",
"rxjs": "5.0.1",
"zone.js": "^0.7.4"
},
"repository": {}
}
这是我的webpack.config.js
// Helper: root() is defined at the bottom
var path = require('path');
var webpack = require('webpack');
// Webpack Plugins
var CommonsChunkPlugin = webpack.optimize.CommonsChunkPlugin;
var autoprefixer = require('autoprefixer');
var HtmlWebpackPlugin = require('html-webpack-plugin');
var ExtractTextPlugin = require('extract-text-webpack-plugin');
var CopyWebpackPlugin = require('copy-webpack-plugin');
/**
* Env
* Get npm lifecycle event to identify the environment
*/
var ENV = process.env.npm_lifecycle_event;
var isTestWatch = ENV === 'test-watch';
var isTest = ENV === 'test' || isTestWatch;
var isProd = ENV === 'build:watch';
module.exports = function makeWebpackConfig() {
/**
* Config
* Reference: http://webpack.github.io/docs/configuration.html
* This is the object where all configuration gets set
*/
var config = {};
/**
* Devtool
* Reference: http://webpack.github.io/docs/configuration.html#devtool
* Type of sourcemap to use per build type
*/
if (isProd) {
config.devtool = 'source-map';
}
else if (isTest) {
config.devtool = 'inline-source-map';
}
else {
config.devtool = 'eval-source-map';
}
if (!isTest) {
/**
* Entry
* Reference: http://webpack.github.io/docs/configuration.html#entry
*/
config.entry = isTest ? {} : {
'polyfills': './src/polyfills.ts',
'vendor': './src/vendor.ts',
'app': './src/main.ts' // our angular app
};
}
/**
* Output
* Reference: http://webpack.github.io/docs/configuration.html#output
*/
config.output = isTest ? {} : {
path: root('dist'),
publicPath: isProd ? '/' : 'http://localhost:8080/',
filename: isProd ? 'js/[name].[hash].js' : 'js/[name].js',
chunkFilename: isProd ? '[id].[hash].chunk.js' : '[id].chunk.js'
};
/**
* Resolve
* Reference: http://webpack.github.io/docs/configuration.html#resolve
*/
config.resolve = {
// only discover files that have those extensions
extensions: ['.ts', '.js', '.json', '.css', '.scss', '.html'],
};
var atlOptions = '';
if (isTest && !isTestWatch) {
// awesome-typescript-loader needs to output inlineSourceMap for code coverage to work with source maps.
atlOptions = 'inlineSourceMap=true&sourceMap=false';
}
/**
* Loaders
* Reference: http://webpack.github.io/docs/configuration.html#module-loaders
* List: http://webpack.github.io/docs/list-of-loaders.html
* This handles most of the magic responsible for converting modules
*/
config.module = {
rules: [
// Support for .ts files.
{
test: /\.ts$/,
loaders: ['awesome-typescript-loader?' + atlOptions, 'angular2-template-loader', '@angularclass/hmr-loader'],
exclude: [isTest ? /\.(e2e)\.ts$/ : /\.(spec|e2e)\.ts$/, /node_modules\/(?!(ng2-.+))/]
},
// copy those assets to output
{
test: /\.(png|jpe?g|gif|svg|woff|woff2|ttf|eot|ico)(\?v=[0-9]\.[0-9]\.[0-9])?$/,
loader: 'file-loader?name=fonts/[name].[hash].[ext]?'
},
// Support for *.json files.
{test: /\.json$/, loader: 'json-loader'},
// Support for CSS as raw text
// use 'null' loader in test mode (https://github.com/webpack/null-loader)
// all css in src/style will be bundled in an external css file
{
test: /\.css$/,
exclude: root('src', 'app'),
loader: isTest ? 'null-loader' : ExtractTextPlugin.extract({ fallback: 'style-loader', use: ['css-loader', 'postcss-loader']})
},
// all css required in src/app files will be merged in js files
{test: /\.css$/, include: root('src', 'app'), loader: 'raw-loader!postcss-loader'},
// support for .scss files
// use 'null' loader in test mode (https://github.com/webpack/null-loader)
// all css in src/style will be bundled in an external css file
{
test: /\.(scss|sass)$/,
exclude: root('src', 'app'),
loader: isTest ? 'null-loader' : ExtractTextPlugin.extract({ fallback: 'style-loader', use: ['css-loader', 'postcss-loader', 'sass-loader']})
},
// all css required in src/app files will be merged in js files
{test: /\.(scss|sass)$/, exclude: root('src', 'style'), loader: 'raw-loader!postcss-loader!sass-loader'},
// support for .html as raw text
// todo: change the loader to something that adds a hash to images
{test: /\.html$/, loader: 'raw-loader', exclude: root('src', 'index.html')}
]
};
if (isTest && !isTestWatch) {
// instrument only testing sources with Istanbul, covers ts files
config.module.rules.push({
test: /\.ts$/,
enforce: 'post',
include: path.resolve('src'),
loader: 'istanbul-instrumenter-loader',
exclude: [/\.spec\.ts$/, /\.e2e\.ts$/, /node_modules/]
});
}
if (!isTest || !isTestWatch) {
// tslint support
config.module.rules.push({
test: /\.ts$/,
enforce: 'pre',
loader: 'tslint-loader'
});
}
/**
* Plugins
* Reference: http://webpack.github.io/docs/configuration.html#plugins
* List: http://webpack.github.io/docs/list-of-plugins.html
*/
config.plugins = [
// Define env variables to help with builds
// Reference: https://webpack.github.io/docs/list-of-plugins.html#defineplugin
new webpack.DefinePlugin({
// Environment helpers
'process.env': {
ENV: JSON.stringify(ENV)
}
}),
// Workaround needed for angular 2 angular/angular#11580
new webpack.ContextReplacementPlugin(
// The (\\|\/) piece accounts for path separators in *nix and Windows
/angular(\\|\/)core(\\|\/)(esm(\\|\/)src|src)(\\|\/)linker/,
root('./src') // location of your src
),
// Tslint configuration for webpack 2
new webpack.LoaderOptionsPlugin({
options: {
/**
* Apply the tslint loader as pre/postLoader
* Reference: https://github.com/wbuchwalter/tslint-loader
*/
tslint: {
emitErrors: false,
failOnHint: false
},
/**
* Sass
* Reference: https://github.com/jtangelder/sass-loader
* Transforms .scss files to .css
*/
sassLoader: {
//includePaths: [path.resolve(__dirname, "node_modules/foundation-sites/scss")]
},
/**
* PostCSS
* Reference: https://github.com/postcss/autoprefixer-core
* Add vendor prefixes to your css
*/
postcss: [
autoprefixer({
browsers: ['last 2 version']
})
]
}
})
];
if (!isTest && !isTestWatch) {
config.plugins.push(
// Generate common chunks if necessary
// Reference: https://webpack.github.io/docs/code-splitting.html
// Reference: https://webpack.github.io/docs/list-of-plugins.html#commonschunkplugin
new CommonsChunkPlugin({
name: ['vendor', 'polyfills']
}),
// Inject script and link tags into html files
// Reference: https://github.com/ampedandwired/html-webpack-plugin
new HtmlWebpackPlugin({
template: './index.html',
chunksSortMode: 'dependency'
}),
// Extract css files
// Reference: https://github.com/webpack/extract-text-webpack-plugin
// Disabled when in test mode or not in build mode
new ExtractTextPlugin({filename: 'css/[name].[hash].css', disable: !isProd})
);
}
// Add build specific plugins
if (isProd) {
config.plugins.push(
// Reference: http://webpack.github.io/docs/list-of-plugins.html#noerrorsplugin
// Only emit files when there are no errors
new webpack.NoEmitOnErrorsPlugin(),
// // Reference: http://webpack.github.io/docs/list-of-plugins.html#dedupeplugin
// // Dedupe modules in the output
// new webpack.optimize.DedupePlugin(),
// Reference: http://webpack.github.io/docs/list-of-plugins.html#uglifyjsplugin
// Minify all javascript, switch loaders to minimizing mode
new webpack.optimize.UglifyJsPlugin({sourceMap: true, mangle: { keep_fnames: true }}),
// Copy assets from the public folder
// Reference: https://github.com/kevlened/copy-webpack-plugin
new CopyWebpackPlugin([{
from: root('src/public')
}])
);
}
/**
* Dev server configuration
* Reference: http://webpack.github.io/docs/configuration.html#devserver
* Reference: http://webpack.github.io/docs/webpack-dev-server.html
*/
config.devServer = {
contentBase: './src/public',
historyApiFallback: true,
quiet: true,
stats: 'minimal' // none (or false), errors-only, minimal, normal (or true) and verbose
};
return config;
}();
// Helper functions
function root(args) {
args = Array.prototype.slice.call(arguments, 0);
return path.join.apply(path, [__dirname].concat(args));
}
按照评论的要求添加代码之前和之后。
在：
import { Component } from '@angular/core';
@Component({
selector: 'app',
template: `<h1>Hello {{name}}</h1>`,
})
export class AppComponent { name = 'Angular'; }
后：
import { Component } from '@angular/core';
@Component({
selector: 'app',
template: `<h1>Hello {{name}}</h1>`,
})
export class AppComponent { name = 'Angula'; }
答案 0 :(得分：0)
基于选择器，在DOM中呈现的元素。
你应该小心
答案 1 :(得分：0)
对于我来说，出于某种原因，我在热重载时得到的相同，原因是在我的组件中调用了这个：
constructor(private changeDetectorRef: ChangeDetectorRef) {
}
...
this.changeDetectorRef.detectChanges();
我删除了对detectChanges()的调用后，热重新加载了。
我正在使用Angular 6.0.3。