feat: offlineCache cachePolicy

Author: farfromrefug

src/https/request.android.ts

@@ -496,11 +496,16 @@ export function createRequest(opts: HttpsRequestOptions, useLegacy: boolean = tr
             case 'onlyCache':
                 cacheControlBuilder = cacheControlBuilder.onlyIfCached();
                 break;
+            case 'offlineCache':
+                cacheControlBuilder = cacheControlBuilder.onlyIfCached().maxStale(Number.MAX_VALUE, java.util.concurrent.TimeUnit.SECONDS);
+                break;
             case 'ignoreCache':
                 cacheControlBuilder = cacheControlBuilder.noCache();
                 break;
         }
         request.cacheControl(cacheControlBuilder.build());
+    } else if (opts.nativeCachePolicy) {
+        request.cacheControl(opts.nativeCachePolicy);
     }
 
     // const methods = {

src/https/request.ios.ts

@@ -1,6 +1,6 @@
 import { File, ImageSource, Utils } from '@nativescript/core';
 import { CacheOptions, HttpsFormDataParam, HttpsRequest, HttpsRequestOptions, HttpsResponse, HttpsSSLPinningOptions, HttpsResponseLegacy as IHttpsResponseLegacy } from '.';
-import { getFilenameFromUrl, HttpResponseEncoding, parseJSON } from './request.common';
+import { HttpResponseEncoding, getFilenameFromUrl, parseJSON } from './request.common';
 export { HttpResponseEncoding, addInterceptor, addNetworkInterceptor } from './request.common';
 
 let cache: NSURLCache;
@@ -388,13 +388,16 @@ export function createRequest(opts: HttpsRequestOptions, useLegacy: boolean = tr
             case 'noCache':
                 manager.setDataTaskWillCacheResponseBlock((session, task, cacheResponse) => null);
                 break;
+            case 'offlineCache':
             case 'onlyCache':
                 manager.requestSerializer.cachePolicy = NSURLRequestCachePolicy.ReturnCacheDataDontLoad;
                 break;
             case 'ignoreCache':
                 manager.requestSerializer.cachePolicy = NSURLRequestCachePolicy.ReloadIgnoringLocalCacheData;
                 break;
         }
+    } else if (opts.nativeCachePolicy) {
+        manager.requestSerializer.cachePolicy = opts.nativeCachePolicy;
     } else {
         manager.requestSerializer.cachePolicy = NSURLRequestCachePolicy.UseProtocolCachePolicy;
     }