Completed the JS localization API document

docs/en/UI/AspNetCore/JavaScript-API/Localization.md

@@ -26,9 +26,15 @@ var str = abp.localization.localize('HelloWorld', 'Test');
 
 `HelloWorld` is the text to localize, where `Test` is the localization resource name here.
 
+### Fallback Logic
+
+If given texts was not localized, localization method returns the given key as the localization result.
+
 ### Default Localization Resource
 
-If you don't specify the localization resource name, it uses the **default localization resource** defined on the `AbpLocalizationOptions` (see the *Default Resource* section above). Example:
+If you don't specify the localization resource name, it uses the **default localization resource** defined on the `AbpLocalizationOptions` (see the [localization document](../../../Localization.md)).
+
+**Example: Using the default localization resource**
 
 ````js
 var str = abp.localization.localize('HelloWorld'); //uses the default resource
@@ -39,8 +45,99 @@ var str = abp.localization.localize('HelloWorld'); //uses the default resource
 If your localized string contains arguments, like `Hello {0}, welcome!`, you can pass arguments to the localization methods. Examples:
 
 ````js
-var str1 = abp.localization.getResource('Test')('HelloWelcomeMessage', 'John');
+var testSource = abp.localization.getResource('Test');
+var str1 = testSource('HelloWelcomeMessage', 'John');
 var str2 = abp.localization.localize('HelloWelcomeMessage', 'Test', 'John');
 ````
 
-Assuming the `HelloWelcomeMessage` is localized as `Hello {0}, welcome!`, both of the samples above produce the output `Hello John, welcome!`.
+Assuming the `HelloWelcomeMessage` is localized as `Hello {0}, welcome!`, both of the samples above produce the output `Hello John, welcome!`.
+
+## Other Properties & Methods
+
+### abp.localization.values
+
+`abp.localization.values` property stores all the localization resources, keys and their values.
+
+### abp.localization.isLocalized
+
+Returns a boolean indicating that if the given text was localized or not.
+
+**Example**
+
+````js
+abp.localization.isLocalized('ProductName', 'MyResource');
+````
+
+Returns `true` if the `ProductName` text was localized for the `MyResource` resource. Otherwise, returns `false`. You can leave the resource name empty to use the default localization resource.
+
+### abp.localization.defaultResourceName
+
+`abp.localization.defaultResourceName` can be set to change the default localization resource. You normally don't set this since the ABP Framework automatically sets is based on the server side configuration.
+
+### abp.localization.currentCulture
+
+`abp.localization.currentCulture` returns an object to get information about the **currently selected language**.
+
+An example value of this object is shown below:
+
+````js
+{
+  "displayName": "English",
+  "englishName": "English",
+  "threeLetterIsoLanguageName": "eng",
+  "twoLetterIsoLanguageName": "en",
+  "isRightToLeft": false,
+  "cultureName": "en",
+  "name": "en",
+  "nativeName": "English",
+  "dateTimeFormat": {
+    "calendarAlgorithmType": "SolarCalendar",
+    "dateTimeFormatLong": "dddd, MMMM d, yyyy",
+    "shortDatePattern": "M/d/yyyy",
+    "fullDateTimePattern": "dddd, MMMM d, yyyy h:mm:ss tt",
+    "dateSeparator": "/",
+    "shortTimePattern": "h:mm tt",
+    "longTimePattern": "h:mm:ss tt"
+  }
+}
+````
+
+### abp.localization.languages
+
+Used to get list of all **available languages** in the application. An example value of this object is shown below:
+
+````js
+[
+  {
+    "cultureName": "en",
+    "uiCultureName": "en",
+    "displayName": "English",
+    "flagIcon": null
+  },
+  {
+    "cultureName": "fr",
+    "uiCultureName": "fr",
+    "displayName": "Français",
+    "flagIcon": null
+  },
+  {
+    "cultureName": "pt-BR",
+    "uiCultureName": "pt-BR",
+    "displayName": "Português",
+    "flagIcon": null
+  },
+  {
+    "cultureName": "tr",
+    "uiCultureName": "tr",
+    "displayName": "Türkçe",
+    "flagIcon": null
+  },
+  {
+    "cultureName": "zh-Hans",
+    "uiCultureName": "zh-Hans",
+    "displayName": "简体中文",
+    "flagIcon": null
+  }
+]
+````
+

docs/en/docs-nav.json

@@ -447,6 +447,10 @@
                   "text": "Overall",
                   "path": "UI/AspNetCore/JavaScript-API/Index.md"
                 },
+                {
+                  "text": "Localization",
+                  "path": "UI/AspNetCore/JavaScript-API/Localization.md"
+                },
                 {
                   "text": "AJAX",
                   "path": "UI/AspNetCore/JavaScript-API/Ajax.md"