Allow adding and removing resource Ids from a Localization. (#197)

* Allow adding and removing resource Ids from a Localization.

* Rename onLanguageChange to onChange

Author: zbraniecki

fluent-dom/src/dom_localization.js

@@ -45,8 +45,8 @@ export default class DOMLocalization extends Localization {
     };
   }
 
-  onLanguageChange() {
-    super.onLanguageChange();
+  onChange() {
+    super.onChange();
     this.translateRoots();
   }
 

fluent-dom/src/localization.js

@@ -24,6 +24,16 @@ export default class Localization {
       new CachedAsyncIterable(this.generateMessages(this.resourceIds));
   }
 
+  addResourceIds(resourceIds) {
+    this.resourceIds.push(...resourceIds);
+    this.onChange();
+  }
+
+  removeResourceIds(resourceIds) {
+    this.resourceIds = this.resourceIds.filter(r => !resourceIds.includes(r));
+    this.onChange();
+  }
+
   /**
    * Format translations and handle fallback if needed.
    *
@@ -134,14 +144,14 @@ export default class Localization {
   }
 
   handleEvent() {
-    this.onLanguageChange();
+    this.onChange();
   }
 
   /**
    * This method should be called when there's a reason to believe
    * that language negotiation or available resources changed.
    */
-  onLanguageChange() {
+  onChange() {
     this.ctxs =
       new CachedAsyncIterable(this.generateMessages(this.resourceIds));
   }