refactor(ImageUrl): extract exposeResourcesToView() method.

Addressed to #927

No functional changes.

Author: php-coder

src/main/java/ru/mystamps/web/Url.java

@@ -141,15 +141,14 @@ public static Map<String, String> asMap(boolean production) {
 		map.put("SUGGEST_SERIES_CATEGORY", SUGGEST_SERIES_CATEGORY);
 
 		if (serveContentFromSingleHost) {
-			// Constants sorted in an ascending order.
+			ImageUrl.exposeResourcesToView(map);
+			
 			map.put("BOOTSTRAP_CSS", BOOTSTRAP_CSS);
 			map.put("BOOTSTRAP_JS", BOOTSTRAP_JS);
 			map.put("CATALOG_UTILS_JS", CATALOG_UTILS_JS);
 			map.put("COLLECTION_INFO_JS", COLLECTION_INFO_JS);
 			map.put("DATE_UTILS_JS", DATE_UTILS_JS);
 			map.put("FAVICON_ICO", FAVICON_ICO);
-			map.put("GET_IMAGE_PAGE", ImageUrl.GET_IMAGE_PAGE);
-			map.put("GET_IMAGE_PREVIEW_PAGE", ImageUrl.GET_IMAGE_PREVIEW_PAGE);
 			map.put("JQUERY_JS", JQUERY_JS);
 			map.put("MAIN_CSS", MAIN_CSS);
 			map.put("PARTICIPANT_ADD_JS", PARTICIPANT_ADD_JS);
@@ -158,15 +157,29 @@ public static Map<String, String> asMap(boolean production) {
 			map.put("SERIES_ADD_JS", SERIES_ADD_JS);
 			map.put("SERIES_INFO_JS", SERIES_INFO_JS);
 		} else {
-			// Use a separate domain for our own resources
-			// Constants sorted in an ascending order.
+			// This is a simplest decorator around Map that modifies inserted URLs by prepending
+			// a host for static resources to them.
+			//
+			// I don't want to use ForwardingMap (Guava) or TransformedMap (commons-collections)
+			// as we don't have them in dependencies and I don't want to add them either just for
+			// a few lines of code.
+			//
+			// NOTE: this implementation won't work as expected when a caller uses putAll(),
+			// putIfAbsent() or modifies a map by other ways.
+			Map<String, String> resourcesMap = new HashMap<String, String>(map) {
+				@Override
+				public String put(String key, String value) {
+					// Use a separate domain for our own resources
+					return map.put(STATIC_RESOURCES_URL + key, value);
+				}
+			};
+			
+			ImageUrl.exposeResourcesToView(resourcesMap);
+			
 			map.put("CATALOG_UTILS_JS", STATIC_RESOURCES_URL + CATALOG_UTILS_JS);
 			map.put("COLLECTION_INFO_JS", STATIC_RESOURCES_URL + COLLECTION_INFO_JS);
 			map.put("DATE_UTILS_JS", STATIC_RESOURCES_URL + DATE_UTILS_JS);
 			map.put("FAVICON_ICO", STATIC_RESOURCES_URL + FAVICON_ICO);
-			map.put("GET_IMAGE_PAGE", STATIC_RESOURCES_URL + ImageUrl.GET_IMAGE_PAGE);
-			// CheckStyle: ignore LineLength for next 1 line
-			map.put("GET_IMAGE_PREVIEW_PAGE", STATIC_RESOURCES_URL + ImageUrl.GET_IMAGE_PREVIEW_PAGE);
 			map.put("MAIN_CSS", STATIC_RESOURCES_URL + MAIN_CSS);
 			map.put("PARTICIPANT_ADD_JS", STATIC_RESOURCES_URL + PARTICIPANT_ADD_JS);
 			map.put("SERIES_ADD_JS", STATIC_RESOURCES_URL + SERIES_ADD_JS);

src/main/java/ru/mystamps/web/feature/image/ImageUrl.java

@@ -17,19 +17,27 @@
  */
 package ru.mystamps.web.feature.image;
 
+import java.util.Map;
+
 /**
  * Image-related URLs.
  *
  * Should be used everywhere instead of hard-coded paths.
  *
  * @author Slava Semushin
  */
+@SuppressWarnings("PMD.CommentDefaultAccessModifier")
 public final class ImageUrl {
 
-	public static final String GET_IMAGE_PAGE         = "/image/{id}";
-	public static final String GET_IMAGE_PREVIEW_PAGE = "/image/preview/{id}";
+	static final String GET_IMAGE_PAGE         = "/image/{id}";
+	static final String GET_IMAGE_PREVIEW_PAGE = "/image/preview/{id}";
 
 	private ImageUrl() {
 	}
 
+	public static void exposeResourcesToView(Map<String, String> resources) {
+		resources.put("GET_IMAGE_PAGE", GET_IMAGE_PAGE);
+		resources.put("GET_IMAGE_PREVIEW_PAGE", GET_IMAGE_PREVIEW_PAGE);
+	}
+	
 }