Merge pr ionic-team#692 Support Range requests for reading local files

Author: Arik

src/ios/IONAssetHandler.m

@@ -17,17 +17,18 @@ - (instancetype)initWithBasePath:(NSString *)basePath andScheme:(NSString *)sche
     return self;
 }
 
-- (void)webView:(WKWebView *)webView startURLSchemeTask:(id <WKURLSchemeTask>)urlSchemeTask
-{
-    NSString * startPath = @"";
-    NSURL * url = urlSchemeTask.request.URL;
-    NSString * stringToLoad = url.path;
-    NSString * scheme = url.scheme;
-
+- (void)webView:(WKWebView *)webView startURLSchemeTask:(id <WKURLSchemeTask>)urlSchemeTask {
+    NSString * startPath = @""; // Initialize startPath
+    NSURL * url = urlSchemeTask.request.URL; // Extract URL from the request
+    NSString * stringToLoad = url.path; // Get the path component of the URL
+    NSString * scheme = url.scheme; // Get the scheme of the URL
+    // Check if the URL's scheme matches the custom scheme
     if ([scheme isEqualToString:self.scheme]) {
+    // If the path starts with "/_app_file_", strip this prefix
         if ([stringToLoad hasPrefix:@"/_app_file_"]) {
             startPath = [stringToLoad stringByReplacingOccurrencesOfString:@"/_app_file_" withString:@""];
         } else {
+        // Otherwise, build the path relative to self.basePath
             startPath = self.basePath ? self.basePath : @"";
             if ([stringToLoad isEqualToString:@""] || [url.pathExtension isEqualToString:@""]) {
                 startPath = [startPath stringByAppendingString:@"/index.html"];
@@ -38,28 +39,74 @@ - (void)webView:(WKWebView *)webView startURLSchemeTask:(id <WKURLSchemeTask>)ur
     }
     NSError * fileError = nil;
     NSData * data = nil;
-    if ([self isMediaExtension:url.pathExtension]) {
-        data = [NSData dataWithContentsOfFile:startPath options:NSDataReadingMappedIfSafe error:&fileError];
-    }
-    if (!data || fileError) {
-        data =  [[NSData alloc] initWithContentsOfFile:startPath];
-    }
-    NSInteger statusCode = 200;
-    if (!data) {
-        statusCode = 404;
+    NSString * mimeType = [self getMimeType:url.pathExtension]; // Get MIME type based on file extension
+       NSInteger statusCode = 200; // Default to 200 OK status
+       NSURL * localUrl = [NSURL URLWithString:url.absoluteString]; // Create a URL object
+       id response = nil;
+
+       NSFileManager *fileManager = [NSFileManager defaultManager];
+       if (![fileManager fileExistsAtPath:startPath]) {
+           // File not found, return 404
+         statusCode = 404;
+         response = [[NSHTTPURLResponse alloc] initWithURL:localUrl statusCode:statusCode HTTPVersion:nil headerFields:@{ @"Content-Type" : mimeType, @"Cache-Control": @"no-cache" }];
+         [urlSchemeTask didReceiveResponse:response];
+         [urlSchemeTask didFinish];
+         return;
+      }
+
+    // Check for Range header
+    NSString *rangeHeader = [urlSchemeTask.request valueForHTTPHeaderField:@"Range"];
+    NSUInteger fileLength = (NSUInteger)[[fileManager attributesOfItemAtPath:startPath error:nil] fileSize];
+
+    if (rangeHeader) {
+        NSRange range = NSMakeRange(NSNotFound, 0);
+        if ([rangeHeader hasPrefix:@"bytes="]) {
+            NSString *byteRange = [rangeHeader substringFromIndex:6];
+            NSArray<NSString *> *rangeParts = [byteRange componentsSeparatedByString:@"-"];
+            NSUInteger start = (NSUInteger)[rangeParts[0] integerValue];
+            NSUInteger end = rangeParts.count > 1 && ![rangeParts[1] isEqualToString:@""] ? (NSUInteger)[rangeParts[1] integerValue] : fileLength - 1;
+            range = NSMakeRange(start, end - start + 1);
+        }
+
+        if (range.location != NSNotFound) {
+            // Ensure range is valid
+            if (range.location >= fileLength) {
+                statusCode = 416; // Requested Range Not Satisfiable
+                response = [[NSHTTPURLResponse alloc] initWithURL:localUrl statusCode:statusCode HTTPVersion:nil headerFields:@{ @"Content-Type" : mimeType, @"Content-Range": [NSString stringWithFormat:@"bytes */%lu", (unsigned long)fileLength], @"Cache-Control": @"no-cache" }];
+                [urlSchemeTask didReceiveResponse:response];
+                [urlSchemeTask didFinish];
+                return;
+            }
+
+            NSFileHandle *fileHandle = [NSFileHandle fileHandleForReadingAtPath:startPath];
+            [fileHandle seekToFileOffset:range.location];
+            data = [fileHandle readDataOfLength:range.length];
+            [fileHandle closeFile];
+
+            statusCode = 206; // Partial Content
+            NSString *contentRange = [NSString stringWithFormat:@"bytes %lu-%lu/%lu", (unsigned long)range.location, (unsigned long)(range.location + range.length - 1), (unsigned long)fileLength];
+            response = [[NSHTTPURLResponse alloc] initWithURL:localUrl statusCode:statusCode HTTPVersion:nil headerFields:@{ @"Content-Type" : mimeType, @"Content-Range": contentRange, @"Content-Length": [NSString stringWithFormat:@"%lu", (unsigned long)range.length], @"Cache-Control": @"no-cache" }];
+        }
     }
-    NSURL * localUrl = [NSURL URLWithString:url.absoluteString];
-    NSString * mimeType = [self getMimeType:url.pathExtension];
-    id response = nil;
-    if (data && [self isMediaExtension:url.pathExtension]) {
-        response = [[NSURLResponse alloc] initWithURL:localUrl MIMEType:mimeType expectedContentLength:data.length textEncodingName:nil];
-    } else {
-        NSDictionary * headers = @{ @"Content-Type" : mimeType, @"Cache-Control": @"no-cache"};
+
+    if (!response) {
+        // Load entire file if no range is requested
+        data = [NSData dataWithContentsOfFile:startPath options:NSDataReadingMappedIfSafe error:&fileError];
+        if (!data || fileError) {
+            data =  [[NSData alloc] initWithContentsOfFile:startPath];
+        }
+
+        if (!data) {
+            statusCode = 404;
+        }
+
+        NSDictionary *headers = @{ @"Content-Type" : mimeType, @"Cache-Control": @"no-cache" };
         response = [[NSHTTPURLResponse alloc] initWithURL:localUrl statusCode:statusCode HTTPVersion:nil headerFields:headers];
-    }
-    
+    }   // Send response and data to the WKWebView
     [urlSchemeTask didReceiveResponse:response];
-    [urlSchemeTask didReceiveData:data];
+    if (data) {
+       [urlSchemeTask didReceiveData:data];
+    }
     [urlSchemeTask didFinish];
 
 }