build: use Webpack for building frontend.

The dependencies have been updated with:
$ ./mvnw -Pfrontend frontend:npm -Dfrontend.npm.arguments='install --save-dev webpack webpack-cli babel-loader'
$ ./mvnw -Pfrontend frontend:npm -Dfrontend.npm.arguments='uninstall @babel/cli'

Fix #1455

Author: php-coder

src/main/frontend/package-lock.json

@@ -5,14 +5,16 @@
   "private": true,
   "dependencies": {},
   "devDependencies": {
-    "@babel/cli": "~7.10.1",
     "@babel/core": "~7.10.2",
     "@babel/preset-env": "~7.10.2",
-    "@babel/preset-react": "~7.10.1"
+    "@babel/preset-react": "~7.10.1",
+    "babel-loader": "~8.1.0",
+    "webpack": "~4.43.0",
+    "webpack-cli": "~3.3.12"
   },
   "scripts": {
-    "build": "babel src --out-dir ../../../target/classes/js",
-    "watch": "babel src --out-dir ../../../target/classes/js --watch"
+    "build": "webpack",
+    "watch": "webpack --watch"
   },
   "repository": {
     "type": "git",
@@ -31,11 +33,5 @@
     "url": "https://github.com/php-coder/mystamps/issues",
     "email": "[email protected]"
   },
-  "homepage": "https://github.com/php-coder/mystamps#readme",
-  "babel": {
-    "presets": [
-      "@babel/preset-react",
-      "@babel/preset-env"
-    ]
-  }
+  "homepage": "https://github.com/php-coder/mystamps#readme"
 }

src/main/frontend/package.json

@@ -167,3 +167,5 @@ class AddCatalogNumbersFormView extends React.PureComponent {
 		);
 	}
 }
+
+window.AddCatalogNumbersForm = AddCatalogNumbersForm;

src/main/frontend/src/components/AddCatalogNumbersForm.js

@@ -185,3 +185,5 @@ class AddCatalogPriceFormView extends React.PureComponent {
 		);
 	}
 }
+
+window.AddCatalogPriceForm = AddCatalogPriceForm;

src/main/frontend/src/components/AddCatalogPriceForm.js

@@ -132,3 +132,5 @@ class AddCommentFormView extends React.PureComponent {
 		);
 	}
 }
+
+window.AddCommentForm = AddCommentForm;

src/main/frontend/src/components/AddCommentForm.js

@@ -148,3 +148,5 @@ class AddReleaseYearFormView extends React.PureComponent {
 		);
 	}
 }
+
+window.AddReleaseYearForm = AddReleaseYearForm;

src/main/frontend/src/components/AddReleaseYearForm.js

@@ -174,3 +174,5 @@ class SeriesSaleImportFormView extends React.PureComponent {
 		)
 	}
 }
+
+window.SeriesSaleImportForm = SeriesSaleImportForm;

src/main/frontend/src/components/SeriesSaleImportForm.js

@@ -129,3 +129,5 @@ class ParticipantLink extends React.PureComponent {
 		)
 	}
 }
+
+window.SeriesSalesList = SeriesSalesList;

src/main/frontend/src/components/SeriesSalesList.js

@@ -29,7 +29,7 @@ class SimilarSeriesForm extends React.PureComponent {
 	handleSubmit(event) {
 		event.preventDefault();
 
-		const similarSeriesIds = CatalogUtils.expandNumbers(this.state.similarSeriesIds)
+		const similarSeriesIds = window.CatalogUtils.expandNumbers(this.state.similarSeriesIds)
 			.split(',')
 			.map(number => parseInt(number, 10))
 			.filter(number => !isNaN(number));
@@ -139,3 +139,5 @@ class SimilarSeriesFormView extends React.PureComponent {
 		)
 	}
 }
+
+window.SimilarSeriesForm = SimilarSeriesForm;

src/main/frontend/src/components/SimilarSeriesForm.js

@@ -0,0 +1,35 @@
+const path = require('path');
+
+const SRC_DIR = './src/components/';
+
+// @todo #1455 Remove export of components to window
+module.exports = {
+    mode: 'production',
+    entry: {
+        AddCatalogNumbersForm: SRC_DIR + 'AddCatalogNumbersForm.js',
+        AddCatalogPriceForm:   SRC_DIR + 'AddCatalogPriceForm.js',
+        AddCommentForm:        SRC_DIR + 'AddCommentForm.js',
+        AddReleaseYearForm:    SRC_DIR + 'AddReleaseYearForm.js',
+        SeriesSaleImportForm:  SRC_DIR + 'SeriesSaleImportForm.js',
+        SeriesSalesList:       SRC_DIR + 'SeriesSalesList.js',
+        SimilarSeriesForm:     SRC_DIR + 'SimilarSeriesForm.js'
+    },
+    output: {
+        path: path.resolve(__dirname, '../../../target/classes/js/components'),
+        filename: '[name].js'
+    },
+    module: {
+        rules: [
+            {
+                test: /\.js$/,
+                exclude: /node_modules/,
+                use: {
+                    loader: 'babel-loader',
+                    options: {
+                        presets: [ "@babel/preset-react", "@babel/preset-env" ]
+                    }
+                }
+            }
+        ]
+    }
+}